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Gontents

Proceedings of a Wolffish Culture Workshop

Wolffish Culture: A Productive Partnership- A workshop held at Rimouski, Quebec, June 2002Laura Halfyard and Linda Hiemstra, associate editors

lntroductiontotheworkshop ' ""'6Laura Halfiard

Marketing and Supply lssues

Evaluation of the potential of marine and anadromous fish for cold-water maricultureinQuebec ""'9

Nathalie Le Frangois, Hdline Lemieux and Pierre Blier

Marketing issues and opportunities for farmed wolffish in the United States and Europe .

H. Johnson and L. Halfyard

Cultured wolfifsh (Anarhichas minor) - A potential species for exclusive restaurants? .

Roger Richardsen and Jan J. Johansen

"Gettingtoknowyourproduct" ""'17L.C. Halfyard

Extraction of high-valued biomolecules to diversify mariculture production of wolffish .

Nathalie Le Frangois and Pierre Blier

Culture and Research

Status of wolffish broodstock studies in Quebec

Nathalie Le Frangois and Jean-Denis Dutil

Management of wolffish broodstock

Helge Tveiten

Bull. Aquacul. Assoc. Canada 102-2 (2002)

25

Factors affecting survival and growth during early life stages of spotted wolffish( Anarhichas minor Olafsen)

LB. Falk-Petersen

Biochemical analysis of egg quality and first-feeding condition of thecommon wolffish, An arhichas lupu s

L.C. Halfilard and C.C. Parrish

Susceptibility of spotted wolffish to infectious diseases and use of immunoprophylaxis

S. Espelid

Tolerance, growth and haloplasticity of Atlantic wolffish (Anarhichas lupus) exposedto low and intermediate salinities

Nathalie Le Frangois, Simon Lamarre and Pierre Blier

Special Repoil

Canadianfreshwateraquaculture:Adevelopmentperspective. . . .42M. Gauthier, H. Mercille, M. Parent, J.-F. Thifuult and A. Dumass

Columns

President'smessage ... 5Shawn Robinson

Theviewfromhere-Broodstockgenetics:Awarningtothewise . . . 46Tim Jackson

Departments

AQUA-L, the AAC discussion list . . . 16SustainingmembersoftheAAC .....23

Newaquaculturebooks .....24

DonorstotheStudentEndowmentFund .....41

Calendar - aquaculture courses, workshops, and trade shows. . . . . . 48

29

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39

Bull. AquacuL. Assoc. Canada 102-2 (2002)

President's Column

t is my hon-our and plea-sure to take

up the presiden-tial leadership ofthe Aqua- cultureAssociation ofCanada, an or-ganisation thathas been activelyinvolved with theaquaculture in-

dustry since its inception in 1984. From the time Iwas elected to the board of directors in 1997, I havehad a first-hand view of how the organisation is ac-tiveiy involved in the promotion of information rele-vant to the burgeoning aquaculture industry throughits meetings and publications. I have also seen howit has helped develop new professionals through itsactive student program. Several of the students whoI'rave been involved with our association have goneon to become executive board members of the AACand of other international aquaculture organisations.As president, I will attempt to keep to the long-termobiectives of our association and to maintain andstrengthen our commitment to those goals.

Over the last 18 years many changes have oc-cured in the marine food production industries. Inone sense we are experiencing the curse "May youlive in intere.sting times". Over the course of twogenerations in Canada, we have seen a plateau in theoverall catches from wild harvest fisheries and shiftsin wealth llom the pelagic and groundfish sectors tothe invertebrate sector, notably crustaceans. Thesalmon culture industry has grown on both coasts toproduce almost half a billion dollars of product inthe year 2000 and has essentially entered the matu-ration phase of a cornmodity market. Trout, Arcticchar, halibut, cod, haddock and other culture indus-tries are either scaling up or are in development asthe demand for food increases on a national and in-temational basis. On the shellfish side, mussels andoysters still dominate aquaculture production, but anorder of magnitude less than irnfish. Several othershellfish species are being contemplated and investi-gated. Some groups are now looking at the conceptofintegrated culture using ecologicai principles intheir systems design. Not surprisingly, consideringthe globally-connected world we live in, all of theabove changes are being reflected to various extents

on a world-wide basis.In some ways we are simply following the course

of development of terrestriai agriculture with issuessuch as the intensification ofproduction, zoning,employment, environment and the social shift froma hunter-gather society to one based on farming.The big difference is the speed at which all this ishappening: years vs. centuries. This is a time whenthere are many lessons to be learned, some new andsome old.

We have just finished our l9'h annual meeting andit continued to build on the long tradition ofsuc-cessful meetings that the AAC is known for. Therewas a large international contingent at the meetingin Charlottetown as the First International MusselForum was held within the Aquaculture CanadaoMframework. It was an undeniable success and a sub-stantial amount of information was exchanged dur-ing and after the various talks. This is an aspect thatI would like to encourage and continue to build onfor future meetings: the collaboration of variousaquaculture groups for the centralisation of informa-tion exchange. Organisations such as the AAC, theCanadian Aquaculture Industry Alliance, AquaNet,provincial aquaculture associations, govemmentsand universities should consider co-ordinating theiractivities on a semi-regular basis so that integratedconferences could bring a wide diversity of infor-mation to the meeting delegates.

In the upcoming year, in addition to the prepara-tion for the next AAC meeting in Victoria, BC (Oc-tober 29-November 1, 2003) we will be working onways to continue the development of studentswithin aquacuiture and to build brrdges with otherorganisations. It looks to be a very busy year and Iam looking forward to working with all the mem-bers ofthe board, the association office, and the voi-unteers from the membership. These are a dedicatedand hardworking group of volunteers and we arelucky, as an association, to have them donate theirtirne and talents. They are also very approachable,and so ifyou have any issues or ideas that are rele-vant to the association, please do not hesitate tocontact them or myself.

Shawn Robinson.Biological Station, DFO, St. Andrews

( e -mail ro bins onsm@ mar. dfo - mpo. g c. c a,tel 506 529-5932)

Bull. Aquacul. Assoc. Canada 102-2 (2002)

From the workshop coordinator

n early June 2002, a 2-day workshop entitledWolffish Culture: A Productive Partnershipwas held in Rimouski, Quebec. The event was

hosted jointly by govemment, research and industrypafiners fiom Quebec, Newfoundland and Norway.Support came from many provincial govermentsources in Quebec, including MAPAQ (Ministdre de1'Agricr.rlture, des P6cheries et de l'Alimentation duQu6bec), DEC (D6veloppement Economique deCanada) and SODIM (Soci6t6 pour le d6veloppementde f industrie maricole). Support was also providedby AquaNet, the National Research Council and theNewfoundland Department of Fisheriesand Aquaculture. Support from Nor-waywas provided by the Norwegian Industrialand Regional Development Fund. Work-shop coordination and facilities were pro-vided by the Universit6 du Qu6bec dRirnouski, the Marine Institute of Memo-rial University of Newfoundland, and theUniversity of Tromso. The Aquaculture

Partners in the "joys"ofcoordinating thelvorkshop were Laura Halfyard, MI-MUNlleft;, Nathalie Le Frangois, uaraq-uqaR(centre) and Helge Tveiten NFH-Univer-sity of Tromso.

Cu lture:Partnership

Association of Canada supported the workshop bypublishing these proceedings.

The workshop provided an opportunity lor theaquaculture industry and research community todiscuss various aspects of wolffish culture, incir-rd-ing the culture strategies and technology used dur-ing the production cycle of the spotted (Anarhichosntinor) and common wolffish (A. luptrs). Private in-terests involved in wolffish cultivation present atthe event were Akvaplan-niva and Troms Steinbitof Nor-way, Marifin Inc. of Quebec, and Atlantic

Wolff ishA Productive

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L&The gathering of the "wolffish crew' for the First Wolffish Culture Workshop (Photo: M. B6langer)

Bull. Aquacul. Assoc. Canada 102-2 (2002)

Agrifoods Ltd. of Newfoundland.

The workshop provided a forum for presentationand discussion of various marketing issues includ-ing the European and North American marketniches for wolffish fillets and leather products, po-tential names for the product, problem offat deposi-tion in the tissues, consumer preferences for tasteand texture, and marketing strategies.

A banquet and seafood demonstration provided in-sight into the potential of this highquality white-fleshed product as ahigh-end restaurant food and as aquality leather product. Marketing Commonstrategies will need todelve into these variousoptions to increase theeconomic returns ofwolffi sh crrlture. particu-larly since the culturetechnology is. at present.primarily reliant on ex-pensive land-based sys-tems.

Dr-rring the past 20 years,research into culture

Spotted wolffish(Photo: Memorial Uni-versity)

methods has enabled the successful completion ofthe full life-cycle of wolffish in captivity. Issuesthat need to be addressed in the future include: dif-ferences in the culture performance of the spottedand common wolffish, and the refinement of culturetechniques for the various life stages to improve ef-ficiencies and to reduce the timeline of the produc-tion cycle. Growth needs to be improved throughdevelopments in feeds and feeding methods, by op-timizing environmental conditions, and by monitor-ing health risks. Improvements in broodstock nutri-

wolffish (A. Lupus) (Photo: Memorial University)

Bill. Aquacul. Assoc. Canada 102-2 (2002)

tion, genetics and reproductive strategies shouldalso increase egg quality and survival rates.

Much of the technology used for wolffish culturehas been adapted from existing salmonid and marinefinfish technology, particularly raceway andland-based tank systems. The financial feasibility ofculturing wolffish in the various rearing systems,however, needs to be investigated to improve infor-mation available to investors. Also, the industry willneed to develop in a controlled manner to keep themarketing, hatchery production and grow-outphases synchronized. Private sector investment willalso be required to promote the development of thisindustry.

Wolffish culture shows promise for regions of Can-ada and Norway that have high-quality seawater andthe necessary infrastructure support. Ofparticular in-terest are suitable locations with the space forland-based systems, relatively cold temperatures, anda labour force to support the industry and foster eco-nomic growth. This workshop provided an oppoftu-nity for representatives of industry, govemment andresearch to discuss the various aspects ofwolffish cu1-ture and to plan collaborative activities for the contin-ued growth of this emerging industry.

- Laura C. HafuardM ar ine I nstitute, M emo rial U niv e rs iN

Workshop Sponsors

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Evaluation of the Potential of Marine and Anadromous Fishfor Cold-water Mariculture in Quebec

Nathalie Le Frangois, Hiline Lemieux and Pierre Blier

Concern about overexploitation ofwild aquatic resources, slow recovery ofthe groundfish fisheries, and the need to encourage the diversification ofthemariculture industry in Quebec (Canada) provides a strong incenfive to ex-plore the potential of marine and anadromous fish species for cold-watermariculture. Starting from a list of over 40 indigenous fish of potential com-mercial interest, a biotechnical review was initiated. Technical sheets foreach species were produced and aquaculture-based selection criteria weredeveloped for the three approaches to aquaculture development (completeproduction cycle (egg to egg), on-growing, and stock enhancement). On thebasis of the required biological parameters, species were ranked accordingto their degree of suitability for each type of culture. The final classificationanalysis for fish cultured through the complete production cycle positionedthe Atlantic wolffish as the top candidate species (score of 91%o), followedby spotted wolff,rsh and Arctic char (scores of 87%). Growth rate, optimaltemperature for growth, minimal lethal temperature, duration of the weaningperiod, 1arva1 size, and feed requirements were the determining criteria. Theinclusion of four species of cultured salmonids (salmon, trout, Arctic charr,and brook charr) in the evaluation procedure allowed the validation of themethod and comparison among species of their suitability for mariculture.

lntroduction

A wide array of marine fish species (t: a7) found inthe coastal environment of Quebec were evaluated fortheir potential use in diversifying the aquaculture in-dustry.(r) This paper is presented in the form of a casestucly of a cold-water maritime region with underde-veloped aquaculture potential. There has been a pro-nounced decline in landings from the traditional fish-ery in Quebec, so there is a need for economic diversi-fication in the maritime regions of the province. Que-bec's 12 000 km coastline is characterizedby extremetemperature conditions and extensive ice coverage.Mariculture activity is cur-rently limited to cultivationof rnussels and scallops. A few commercial and re-search initiatives on marine fish cultr-rre have been at-tempted, including the on-growing of juvenile codand winter flounder taken from the commercial fish-ery, and the on-growing of cultured brook charr j tlve-niles in seawater. Presently there are no marine fishculture facilities in operation. There is, however, ahealthy freshu,ater salmonid culture industry produc-ing rainbow trout, Arctic charr, and brook charr. Theemerging mariculture industiy in Quebec will be ableto rely on the high-caliber research facilities and solidscientific expertise that exist in the province.

The provincial govemment, in collaboration withthe aquaculture industry and research and universityrepresentatives, developed a strategic plan foraquaculture development in 2000.(') Part of the planinvolved the evaluation of the potential of marinefinhsh species for mariculture development in Que-bec. The objective ofthe evaluation was to conduct aversatile, ob jective, large-sca1e study examining threeprincipal mariculture production strategies: completeproduction cycle (egg to egg), stock enhancement,and on-growing ofjuveniles. The evaluation involvedthe use of well-defined criteria appropriate for Que-bec's environmental and economic situation to (i)identify the species with the most potential for cuiti-vation, (ii) clearly assess the potential for risk associ-ated with a given species, (iii) identify n&D needs, and(iv) provide the basis for concerted action by the fi-nancial, government and research communities to de-velop marine fish mariculture in the province.

Materialand Methods

The first step in developing the strategic plan foraquaculture development was the compilation of a listof 47 fish species based on the description of thedemersal fish assernblage for the east coast of North

Bull. Aquacrl. Assoc. Ctutatla 102-2 (2002)

America(3) and completed using the reference bookAtlantic Fishes of Canada.$t The list was reviewedand refined by several mariculture and fisheries ex-perts. The list was not exhaustive, but was comprisedof a wide array of fish species in order to clearly testthe outcomes of the proposed selection procedures.Technical sheets containing relevant information oncriticai aspects ofinterest in assessing the potential ofthe fish for each type of aquaculture was developedfor each species. The species were then subjected to aselection procedure that involved two stages ofselec-tion, followed by a final classification of the suitabil-ity of the species for mariculture. The first stage of se-lection used simple, unequivocal and discriminatingcriteria of primary importance in Quebec's environ-mental, technicai and economic context. In this firstselection, a species was either rejected or directed to-ward a specific mariculture scenario in which the spe-cies was subjected to a second stage ofselection.

The species that appeared most suitable for each ofthe production strategies (complete cyc1e,on-growing, or stock enhancement) were subrrittedfor a closer evaluation oftheir potential using criteriaspecific to each strategy. At this second stage ofse-lection, the species was either rejected or submittedto a final classification procedure. The final stepidentified species showing the strongest mariculturepotential. Each criteria had a maximal score that con-sidered its relative importance in a given culture situ-ation and its prospects for development. Three fixedrange ofvalues were used for each criteria and the to-tal score was then reported in terms of percentage. Alack of information about the species did not influ-ence the final score, but allowed the rapid identifica-tion of areas of knowledge that were inadequate andcould benefit from research efforts.

Results and Discussion

The final ranking of species deemed suitable for thecomplete-cycle production strategy (the only scenariopresented in this paper) identified the Atlanticwolffish and the spotted wolffish as the marine fishspecies with the most potential for culture in Quebec(scores of 91o/" and 87o/o, respectively). The spottedwolffish ex aequowith Arctic charr (87%). The smalldifference in the score between the two wolfish spe-cies is likely attributable to the difference in the R&oeffort expended on the two species: 10 to 15 years forAtlantic woiffish and 5 to 7 years for spotted wolfish.Despite its lower ranking, the spotted wolffish dis-plays a faster growth rate than the Atlantic wolffish.

Wolfish are the only marine fish species that rankedhigher than most salmonid species, and this occurreddespite their short history as aquaculture species andthe lack of refinement of aquaculture practices. The

main characteristics that favour wolffish for mari-culture are their high tolerance of cold temperature,rapid growth under culture conditions (fish reach 2.5kg in l8 months at 6"to 10'C), resistance to diseaseand suboptimal water qrlality, tolerance of high rear-ing densities ( I 00 kg/m'.y, feed conversion rates thatare similar to salmonids, low complexity of the rear-ing technology (similar to salmoniculture), no re-quirement for live prey because the juveniles are ro-bust and there are no larvai stages, high flesh yield(.45-50%), no directed fisheries, decline of naturalpopulations worldwide, and the availability of Nor-wegian expertise in both the private and researchsectors. Commercial production in Norway willreach I 0 lonnes in 2002.After the selection procedure and prioritization of

the species, the following research priorities wereidentified for wolffish:

1. Technology transfer2. Broodstock collection and juvenile prodr-rction3. Nutrition and reproductive physiology4. Optimization of growth5. Enhancement of prospects for profitability6. Market analysis7. Adapting technologies used with other speciesto lower production costs

The evah-ration program was developed in collabo-ration with Norway (Akvaplan-niva, the University inTromso and the Norwegian Institute of Fisheries andAquaculture Research), Newfoundland (Marine In-stitute and Ocean Science Centre of Memorial Uni-versity of Newfoundland) and Fisheries and OceansCanada (Maurice Lamontagne Institute).

References

l. Le Frangois NR, Lcmicux H, Blier P. 2002. Aqua. Rcs. 33:95- I 08

2. MAPA. 2002. Politique quibdcoise des pd.ches et deI'aquacuhure QSBN 2-550-36301-9). 00-0099, p. 31.Bibliothdquc nationale du Qu6bcc.

3. Mahon R, Brown SK, Zwanenburg KCT, Atkinson DB, BujaKR, Claflin L, Howcll GD, Monaco ME, O'Boylc RN,Sinclair M. 1998. Can. J. Fish. Aquat. Sci. 55: 1704-1738.

4. Scott WB, Scott MG. 1998. Cun. Bull. Fish. Aquut. Sci. 219731 p.

lr{athalie Le Frangois is a researcher at theUniversitd du Qudbec d Rimouski/MAPAQ, CentreAquacole Marin de Grande-Riviire, 6, rue du Parc,Grande-Riviire, Qudbec G)C 1V0 (telephone1 I B-385-225 I (ext. 222), e-mail nathalie.le.francois@ globetrotter.net). Hdline Lemieux is withthe Department of Biology, Universitd du Qudbec dRimouski. Piete Blier is Professor and Head of theDepartment of Biology, Universitd du Qudbec dRimouski.

t0 Bull. Aquacul. Assoc. Canada 102-2 Q002)

Marketing lssues and Opportunitiesfor Farmed Wolffish in the United States and Europe

H. Johnson and L.C. Halfyard

Market infomation suggests that farmed wolffish fillet products would beranked high compared to many other marine species. Wolffish is a leanwhite-fleshed fish with a market niche similar to Dover sole, halibut,monkfish and sea bass. Value-added fillets would be the primary product,but secondary products (e.g., fish leather) and improvements in farming ef-ficiencies should increase the financial returns. Development of marketingstrategies should include defining the name of the product, promoting theproduct to up-scale restaurants, and distinguishing farmed wolffish fromthe wild product.

lntroduction

Aquaculture accounts for approximately 20%o of thetotal world supply of seafood products and is pro-jected to increase to -30"/o by the year 2025. Fish con-sumption in the United States is about 7 kg per capitaand the population is presently about 214 million.Seafbod imports now exceed the net domestic land-ings and Canada is the lead supplier of seafood to theUS marketplace, with value-addedprocessing increas-ing (e.g., cooked and srnoked fi1lets).

The US seafood situation will be affected bylong-term supply constraints, periodic oversupply,and an increased reliance on aquaculture products.Population growth will drive demand for aquacultureproducts and seafood, but environmental groups willalso apply pressure on the aquaculture industry. TheEU seafood market presently has a 3.1 million tradedeficit and, with the decline in supply of North Atlan-tic groundfish species, there is increased interest incultured species. In Er-rrope and some high-end sectorsof the us market, chefs are familiar with wolffish fromthe traditional fishery. Approximately 50,000 metrictons of wild wolffish product comes into the Europeanand American marketplace from Iceland, Russia, theUnited States, Canada, and other countries.

Wolffish Markets

The four Ps of marketing are product, price, place,and promotron. Questions to be asked include: Whatproduct does the r,r,olffish substitute for, in what formwill the market r.vant wolffish, what will the marketpay for wo1ffish, what volume will the market absorb,where wili wolffish be so1d, and how should wolffishbe promoted? Generally the American consumer pre-

fers a seafood product that is skinless, boneless andtasteless! Wolffish is a Iean, pearly white fleshed fishwith a mild sweet taste and firm texture that can sub-stitute for Dover so1e, halibut, monkfish or sea bass.The marketing niche for wild wolffish is aboutus$4.50 per pound ($9.90 per kilogram) (Fig. 1),which is comparable to the results of a recent Euro-pean wolffish marketing study indicating wolffishwould sell for $9-$12 per kilogram.

Preferred products for the US market will probablybe fresh boneless fillets, graded by size. There rnay bea market for a smaller fillet than is currentiy being ob-tained from wild fish (which often produce fi1lets toolarge for single-serving portions). A smailer fillet sizecould also reduce the production cycie for farmedwo1ffish.

Over the past l0 years there has been a substantialdrop in the price of farmed salmon due to increasedglobal production and availability, as well as reducedoperating costs on the farms. Itwouldbe expected thatcost reductions in wolffish farming could be gainedby reducing operating costs and improving feed man-agement strategies.

Identification of the different marketing niches forwolffish products would probably initially be directedto high-end restaurants in both Europe and the UnitedStates. Up-scale supermarkets, supermarket chains,and fish markets may be other venues for select prod-ucts. Finally, value-added products may be developedfor certain sectors. Issues that must be addressed tosuccessfully market wolffish include clearly definingthe name of the product, setting up direct sales organi-zations, promoting to up-scale restaurants, and creat-ing a'buzz' in the seafood sector. Some confusionmay exist as to how to promote wolffish and whatname to use (e.g. wolffish, Atlantic wo1ffish, striped

11BulL. Aquacul. Assoc. Canada 102-2 (2002)

Wolffish Fillet PriceWhere will it fit in the market?

Chilean Sea Bass

Monkfish

Arctic Charr

Hybrid Striped Bass

Wild Wolffish

Orange Roughy

Flounde r

Haddock

Alantic Cod

Turbot

Catfish

Allantic Salmn

Tilapia

Aaska Polluck

$2.00 $4.00 $6.00 $10.00

Per Pou

Figure 1. Various seafood products and US market prices compared with the expectedfillet price(US$ per pound) for wolffish.

wo1ffish, ocean catfish, spotted wolffish, and loup demer). Other examples of this problem have been ad-dressed by developing a distinct name for the product,such as Patagonian toothfish for the Chilean sea bassand goosefish for monkfish. Some of this marketingeffort on wolffish is already being done by an Euro-pean company, Aquanor, which is marketing wildwolffish as 'Loup de mer', but care must be taken todistinguish farmed wolffish from wild product.

It is recommended that the aquaculture industry de-velop incrementally to match market demands to pro-duction volumes. Also, reducing production costs byirnproving feed conversion rates, growth rates, andfillet yield will help alleviate risks when market pricesfluctuate. Farmed wolffish products must be differen-tiated fiom wildwolffish, but generic promotion simi-lar to that used by the US catfish industry would proba-bly foster greater market growth.

There appears to be a market for wolffish in theUnited States but it needs to be developed. Americanseafood lovers like variety and uniqueness and

wolffish would provide another choice on the menu.In his presentation, Chef Roy Butterworth high-lighted the importance of promotion of the product torestaurants and particularly to new culinary chefs wholike to try different products. Supermarket demon-strations, in-store cooking classes and special ban-quet/dinner presentations will help increase knowl-edge of wolffish in the American and European mar-kets.

Howard Johnson is president of H.M. lohnson &Associates, P.O. Box 688, Jacksonville, Oregon97530, USA (telephone 541 899-4975, fax 511899 -497 6, e - maiL howard@ hmj. c om, w eb sitewww.hmj.com). kura C. Halfyard is anaquaculture instructor /researcher with the Schoolof Fisheries, Marine Institute, Memorial Universityof Newfoundland, P.O. Box 4920, St. John's, NFAl C 5R3 (telephone 709 778-0363, fax 7097 7 8 - 0 5 3 5. e - ma i I I a u ra. h alfyo rd @ m i. m u n. c a ).

12 Bull. Aquacul. Assoc. Canada 102-2 (2002)

Cultured Wolffi sh (Anarhichas minor) -A Potential Species for Exclusive Restaurants?

Roger Richardsen and Jan A. Johansen

A market test of cultured wolffi,sh (Anarhichas minor) was done within a se-lected range of exclusive restaurants in Norway, Germany and France. Thestudy indicated that spotted wolffish has good market potential. Respon-dents appreciated the freshness and long shelf-life of the fish. The firm tex-ture ofthe fish was regarded as both an advantage and a disadvantage: theproduct can withstand a lot of pre-treatment and heating in the kitchen, butthe flaky texture of cod and other white fish species was preferred by chefs.The large amounts of mucus (slime) on the skin and the visible fat in the fil-lets lowered the chef s overall positive impression of wolffish. Therefore,the industry still needs to develop feeding and production strategies to fu1lymeet the needs of the market. The most interesting market segments forwolffish should be the hotel and restaurant sector, which could function as agate opener to the consumer in the long run.

lntroduction

The spotted wolffish (Anarhichas minor) is a marinespecies considered to have potential for aquaculture.Research and development have succeeded in demon-strating the fish is suitable for intensive fish farming.Spotted wolffish thrive and grow rapidly at 1ow tem-peratlres, and coastal areas of the North Atlantic seemappropriate for farming this species. The first wolffishcultured in northem Norway will be marketed in2002.

The coastal population in Norway previously con-sidered the spotted lvoiffish to be a low value species,but this has changed considerably during the last de-cade. Today the fish is a common item on menus inNorwegian restaurants. and future supplies from thefarming industry could provide advantages in themarketing of the species. The market price for wild-caught spotted wolffish varies seasonally and the sup-ply is very unstable,('r due to the fact that the fish isiriinly tuk".r as a by-catch in cod fisheries.(') The fluc-tuating catch causes supplies to be unpredictable forchefs and other customers who require a reliable sup-ply of fresh product. The majorrty of wild-caughtspotted wolffish is marketed frozen, so the sensoryquality of the product does not satisfy qual-ity-conscioLrs customers such as chefs inwhite-tablecloth restaurants.(3) Fresh spotted wolffi shwould meet these demands and would be appreciatedby customers.(''a)

Methods of Analyses

The purpose of the market/product test study was toidentify the market position for farmed spottedwolffish in a few European markets by evaluating theperception ofprofessional chefs ofthe sensory quai-ity, price, and convenience of wolffish.

The spotted wolffish used in this test was cultured byTroms Steinbit as, Norlhern Norway. The fish wereshipped gutted, head on, and in sizes that varied be-trveen 3.5 and 5.5 kg. Each participating restaurant re-ceived a 20-kg box of wolffish, fresh chilled in ice forfurther preparation and testing. The restaurants alsoreceived a questionnaire for evaluating the product.A11 together, 32 white-tablecloth restaurants in Nor-way (13), France (10), and Germany (9) participatedin the study. The restaurants were recruited by theNorwegian Seafood Export Council and chosen be-cause of their requirement for high-qualify products.The chefs were interviewed in depth 1-2 weeks afterreceiving the test material.

Perception of Sensory Quality

As shown in Figure 1, the chefs consider whole, gut-ted spotted wolffish as a very fresh fish. Furlher, theprofiles show that a high average score rvas given oneach product attribute except for the natural presenceof slime (mucus). The results from the interviews in-dicate that the relatively high quantity of slime on thefish confused chefs with little or no experience in pre-paring the product. They considered the slime to be an

Bull. Aquacul. Assoc. Canada 102-2 (2002) IJ

indicator of low quality, so a lower score was given.The interviews indicated that chefs experienced inpreparing wolffish associated the high slime contentwith freshness and quality. In addition, experiencedchefs commented that the slime was different frommucus that appears on fish that have begun to deterio-rate. In general, the overall evaluation of the profileanalysis indicates that the chefs liked the quality ofthefish.

As Figure 2 indicates, the Norwegian chefs were sat-isfied with the quality of a prepared meal of wolffish.But futher analyses indicated that fwo product attrib-utes lowered the overall impression of the sensoryquality of the fish. Firstly, more than half the respon-dents perceived the taste of wolffish as being too neu-tral, lacking a distinctive fish taste and having taste el-ements of crustaceans. Secondly, some chefs consid-ered the consistency or texture of the flesh as "tooclosed" or firm. Those chefs preferred a more open orflaky texture, which provides an opportunity to addspice,juice, and/or sauces to the fishbefore serving.

Estimates of Price and Product Categories

Table I indicates the price chefs were willing to payfor whole gutted and fillet products from spottedwolffish. Be aware, however, that these indicativeprices are at the consumer level and are not a farm gateprice. Half the chefs preferred whole, gutted product

to fillets. Time-saving preparation is the main argu-ment in favor of fillets, while the desire for qualitycontrol guides the preference for whole product.

Choice of Future Productand Market Strategy

Our results indicate that chefs perceive the spottedwolffish as a product with strong attributes, some ofwhich will be of major importance when culturedwolffish are introduced into the market place. A ma-jority of the respondents considered the reiativelyhigh amount of slime/mucus on the skin to be a nega-tive attribute. Experienced chefs recognized that rnu-cus is typically present on extremely fresh, chilledspotted wolffish. This characteristic of fresh wolffishshould therefore be communicated to avoid miscon-ceptions about the quality of the product. One of thestrongest product attributes of the fish seems to be theextreme length of the shelf life. Exclusive restaurantsconsider freshness one of the most important productattributes and this feature of wolffish should beemphasised in market communications.

Further, the relatively high amount of visible fat hada negative effect on the overall positive impression ofwolffish. Farmers may have to reduce the fat content,either by starving the fish prior to slaughtering or byreducing the fat content of the feed. The market re-search indicated that chefs generally find that all

Bad freshness

Bad texture

Wrong skin colour

Slimy skin

Dim skin surface

Bad smell

Dislike

Good freshness

Good texture

Proper skin colour

Naturalslime content

Bright skin surface

Fresh smell

Like12

r Norway ffi34France o

56Germany

Figure 1. Profile analysis of whole, gutted spotted wolffish

l4 Bull. Aquacul. Assoc. Canada 102-2 (2002)

Table 1. Estimates of the prices chefs are willing to pay for spottedwolffish.

Price per Kilogram of Product

Product Norway Germany FranceGutted with head on

Fillets

us$6.40

us$8.00

us$7.40

us$ I 0.80

us$7.40

us$ i 1.60

farmed fish are too fatty. A change in the feed formulawould probably be a good approach to produce a cul-tured fish that is similar to wild-caught fish.

Another finding of the study was that culturedwolffish lack the characteristic taste of wild-caughtfish. Some of the chefs evaluated the neutral taste as anelement of uncertainty when they considered whetherthey would buy the fish in the future. This point could,however, be a strong positive attribute in market areassuch as the United States. The only way to alter theperceived taste ofthe flesh is to change the feed for-rnula by including ingredients that are part of the natu-ral food ofthe species.

Several respondents evaluated the texture of theproduct as firm cornpared with seabass(Dicentrarchus labrax') and Atlantic cod (Gadusmorhua). However, some chefs considered the firmstrncture ofthe fillet as an advantage ifthe fish are be-

ing barbecued or exposed to a long lasting heat treat-ment such as during banquets. The firm texfure of theflesh appears to be a product strength and should beemphasised in fufure market promotions.

Farmers should be aware that chefs have an underly-ing negative attitude to fish farming and the quality offarmed fish. Fish farmers, trade associations, and ex-porters have a considerable challenge to improve thecustomer's trust of the industry. Infomation on cul-tured products and communication to the publicshould be based on factual information and documen-tation ofproduct quality and safety in the food pro-duction chain.

This study indicates that spotted wolfhsh has goodmarket potential. The product seems to be ranked on ahigh level, comparable to product like farmed Atlan-tic salmon (Salmo salar). The most interesting marketsegments should be the hotel and restaurant sector,

Tastes bad

Dry

Bad texture

Badappearance

Wrong whitecol0ur

Dislike

Tastes good

Juicy

Good texture

Goodappearance

Proper whitecolour

Like234r Norway o Germany

56ffi France

Figure 2. Profile analysis of prepared meal from spotted wolffish

aa

*aa"

o

?oo

oa

a

aao?Ii!$rffir

flrItra

6twI%INStrar

aa

oo

a

oo

oO

ao

Bull. Aquacul. Assoc. Canada 102-2 (2002) t5

which could function as a gate opener to the consumerin the long run. The quality attributes indicate a partic-ular potential as a "banquet fish" which could be astrong driver of market demand.

References

1. Foss L, Ostli J. 1998. Fraproduksjon til marked:Institusj oneel, o rganisatoriske og markedsme s sige.forholdved oppdrett av marine arter (From production to market: In-stitutional, o rganizational and market unditktns.for cultureof marin species). Report number 9, Norwegian Institute ofFisheries and Aquaculture, Tromso (in Norwegian).

2. Midling K. 199 1. Stamfiskhold og produksjon av steinbityngel(Broodstock and production tf wolffish juvenlle.r). WorkingPaper, Norwegian Institute of Fisheries and Aquaculture,Tromso (in Norwegian).

3. Hansen B. 1998. Det ekslusive restaurantsegmentet I Tyskland.Analyse av .faktorer som har betydning.for markedsfsoring avoppdrettet.flekksteinbit (Exclusive restaurants in Germany :

Analysis of important.factors .for marketing woffish to themarket segment. MSc Thesis, Norwegian College of FisheriesScience, Tromso (in Norwegian).

4. Strsmmesen l. 1998. Marketsmuligheter.for oppdrettet.flekksteinbit? En kvalitativ analyse av eklusive restauronter ILondon (Market possibilities.for cultured wolffish? A qualita-tive analysis within exclusive restaurdnts in London. MScThesis, Norwegian College ofFisheries Science, Tromso (inNorwegian).

Roger Ricardsen and Jan. A. Johnasen are re-searchers at the Norwegian Institute of Fisheriesand Aquaculture, N-9292, Breivika, Tromss, Nor-way (telephone + 47 77 62 90 00,fax + 47 77 629 I 00, e - mail ro g er. ri chards en @ fi s fforsk. no rut.no ).

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t6 Bull. Aquacul. Assoc. Canada 102-2 (2002)

"Getting to Know Your Product"

L.C. Hafuard

"Getting to know your product" was one of the themes of the wolffishworkshop, which was highlighted by an excellent demonstration byChef Roy Butterworth, an award-winning Canadian chef from NewBrunswick. Fresh Norwegian farmed wolffish, produced by TommaMarin, was filleted, prepared and presented in a superb dinner featur-ing roasted wolffish.

Other marketable products from wolffish include leather items madefrom the skin, value-added products such as smoked wolffish, andpossibly biomolecular products.

Chef Roy Butterworth indicated that the high-end restaurant sector isreceptive to seafood products that are unique, mild tasting and verywhite. He also felt that wolffish showed promise for the banquet ser-vice sector since it has a high level of stability when cooked, which isespecially critical as delays often cause concem for the chefabout thethe potential for overcooked or dry dinners!

Opportunities to promote wolffish include demonstrations to variousculinarians, especially those in high-end restaurants, and supermarketin-store cooking classes.

Farmed Norwegian spotted wolffish flown fresh from Tomma Marin, Norway (M. B6langer photo).

I

BuLl. Aquacul. Assoc. Canada 102-2 (2002) I7

Lively discussions of wolffishproduct by the Norwegian, Ca-nadian, and US crew. L to r:Laura Halfyard, Helge TveitenInger Andreassen, HowardJohnson, and Lars OlavSparboe (M. B6langer photo).

The beauty of wolffish leather products wassported by Norwegian researcher SigrunEspelid from FiskeriForskning, who also en-joyed receiving one of the first servings ofroasted wolffish served with wild mushrooms,port wine balsamic syrup, sweet potato andsummer sayory crisp (L.C. Halfyard photo).

Chef Roy Butterworth from NewBrunswick preparing and servingfarmed spotted wolffish to JoeBrown from Memorial University ofNewfoundland, one hungry re-searcher who enjoyed the five-stargourmet meal! (M. B6langer, photo)

18 BulL. Aquacul. Assoc. Canada 102-2 (2002)

The Quebec wolffish crew and 'the slaves' who ran around doing numerous things during the workshop! (L to r:Jean Claude Blais, Marifin Inc., Bruno Archer, Marifin Inc., Nathalie Le Frangois, Simon Lamarre, andDelphine Ditlecadet) (M. B6langer photo).

I ++er dinner rvolffish joke ... What do you get when you feed a wolffish?The finger!!! (L to r:l Stk;:lx\s- =\--\:S-..NS\N\.,..-

Extraction of High-Value Biomoleculesto Diversify Mariculture Production

of Wolffish

Nathalie Le Frangois and Pierre Blier

The profit margin of aquaculture operations based exclusively on flesh pro-duction is vulnerable to fluctuations in market prices and feed, labor and,/orenergy costs, an obstacie to new finfish mariculture initiatives. This projectproposes to evaluate the economic potential of extracting high-valuebiomolecules from cultivated fish to enhance the profitability ofaquaculture. This type ofinformation could encourage interest from privateinvestors in developing the mariculture potential of Quebec's maritime re-gions. The Atlantic and spotted wolfflrsh (Anarhichas lupus and A. minor)have been identified as marine fish species with high potential for cultiva-tion in Quebec's environmental conditions. We propose to evaluate andcompare both species for seasonal and size-related variations in 1) produc-tion of antifreeze proteins, 2) content and properties of antimicrobialpolypeptides, and 3) content and kinetic properties ofdigestive enzymes.

lntroduction

In the Province of Quebec (Canada), there is grow-ing interest in marine fish farming, as the coastal envi-ronment offers an abundance ofrearing sites. The pro-vincial and federal governments are activeiy support-ing the development of mariculture (scallops, mus-sels, finfish, etc.), but there is still no marine-basedproduction of fish in Quebec. The spotted and Atlanticwolffish (Anarhichas minor and A. lupus, respec-tively) have been identified as species with high po-tential in Quebec's environmental conditions.(1)Wolffish are tolerant of the cold, resistant to diseaseand stress, are able to withstand low oxygen as well aslow salinity conditions, and can be reared at very highdensities. They hatch fully developed and readily feedon commercial formulations, so live prey is not re-quired. Because oftheir sedentary habit, they convertmost of their energy to growth and grow rapidly incaptivity. Unlike marine fish species such as Atlanticcod (Gadus morhua) and Atlantic halibut(Hippoglossus hippoglossus), the culture of wolffishis similar to that of salmonids (fecundity, size of eggsand lawae, acceptance of formulated feeds, survival,rearing requirements), making technology transfer tothe wolffish industry easily conceivable.

Wolffish are not targeted by commercial fisheries(by-catch) in Canada and the catches elsewhere(mainly Iceland) can be deficient during the year, pro-

viding opportunities to establish a niche market sup-plied by year-round aquaculture production. Popuiarin Europe, wolffish is a quality product that has neverbeen strongly targeted in North America. Recently,wolffish was given the Gold Award for the best newproduct at the 2000 Intemational Boston SeafoodShow. It features long, thick, white-fleshed fillets,that are delicate in taste, firm in texture, boneless, par-asite-free and rich in omega-3 fatty acids. Norway iscurrently the only producer of cultured wolffish andthere are pre-commercial spotted wolffish farms inthe region of Tromso. Newfoundiand and Quebec areboth presently involved in R&D activities on spottedand Atlantic wolffish, in collaboration with Norway.Iceland and Chile are also interested in these novelmariculture species.

In the aquaculture sector, a company's profitabilitydepends on production costs and market price, whichis subject to regular fluctuations. Therefore, productdiversification could stabilize and potentially in-crease returns. There are three biomolecules thatcould be exffacted lrom wastes of the aquaculrure in-dustry: antifreeze proteins lerl;,(2) antimicrobialpolypeptides (atrar),(3) and digestive enzymes (or;.t+lGiven their numerous applications in diverse biotech-nological fields and, consequently, their high marketprices, these biomolecules could confer a substantialadded value to the basic aquaculture product.

The originality ofthis approach to aquaculture di-

20 Bull. Aquacul. Assoc. Canada 102-2 (2002)

lntegrated Approach for the Evaluation of thePotential for Commercialization of High-Valued

Biomolecules within an Aquaculture Production Cycle

Aquaculture

{}Energy

FacilitiesFeed

l.lan power

0Production

costs

oAntifreeze

protein

FoodsCryopreservation

CryosurgeryResearrh

Biomass

0Biomoleculee>Graction

nuAntimicrobialpolypeptides

Food preservationVaccines &antibiotics

u

Digestiveenzymes

Foods &supplementsDetergentsResearch

FleshLeather

nuNiche

marketsnu

Marketvalue

Financial feasibilitystudy

0Technical and financial

reports

0R&D

versification is in the integration of the possibilitiesfor diversification early in the process ofestablishinga new industry. This conference paper is aimed at thepotential of antifreeze proteins only.

Antifreeze Proteins (AFPs)

Several species of cold-water marine fishes produceantifreeze proteins (,trts) to avoid fieezing of their

tissues. Until now, four AFP forms have been charac-terised.(5) These proteins are over 500x more effectiveat depressing the freezing point of tissue than otherblood osmolytes. They can also modify or suppressgrowth of ice crystals, inhibit recrystallisation, andprotect membranes against cold-induced damage.AFPs are expected to have many applications and arepresently being actively studied. Possible uses forAFPs include incorporation into frozen foods (e.g.,

Addedvalue

0

Bull. Aquacul. Assoc. Canada 102-2 (2002) 21

dairy products) to prevent recrystallisation of ice crys-tals already present in the product (to preserve theoriginal texture), and as cryoprotectants in cell cul-ture, and gamete and organ cryopreservation. Anotherpotential biomedical application lies in cryosurgery.This special technique uses AFps to kill cancerouscells by affecting their action on crystal growth.

The principal source of AFps is plasma from marinefish species living rn cold water. Such fish can haveAFP concentrations ranging from I to 30 g/L ofplasma. The average price of antifreeze proteins isS500lmg. According to predicrions from R F ProleinCanada,(') demand for this resource will soon exceedproduction capacity, so a number of researchers areattempting to develop large-scale aFp production byusing genetic methods such as recombinant DNA.However, reticence about genetically modified or-ganisms (cuos) and the limit imposed by the naturalresource itself could provide a marketing niche fornaturally-derived arps and other biomolecules fromthe aquaculture industry.

Atlantic wolffish synthesize type III AFp in theirblood, the best ofthe three types tested in protectingbovine oocytes from cold-induced damage. AFp pro-duction by wolffish could ailow the rearing of thisspecies in sea cages or net-pens allyear long in Que-bec. ln most fish that have been found to synthetizeAFP, two abiotic factors influence the production ofthe biomoiecule: water temperature and, principally,photoperiod. Atlantic cod (Gadus morhua) and thewinter flounder (Pseudo- pleuronectes americanus)produce AFP seasonally, while the ocean pout(.Macrozoarces americanus) produces AF-pyear-round, although production is higher during thewinter than the summer. Little is known about the pat-tem of production of arp in wolffish. To assess the po-tential of AFp production by a wolffish aquacultureoperation aimed at the biomolecule market, produc-tion should be characterised throughout the year. Con-sidering that intra-species AFP production variationsexist, the difference between species and the effect ofage and size ofthe fish on protein production shouldbe evaluated.

Perspectives

With recent developments in marine biotechnologyand identification of this development axis as a prior-ity for eastern Quebec, the efficient use of by-productsoriginating from fisheries and aquaculture activities

should be assessed. However, before entrepreneurscan include extraction and purification ofhigh-valuebiomolecules in their business plans, more informa-tion is needed on the potential for production ofthesebiomolecules from aquaculture operations, access tomarkets, and the value of these biomolecules. There-fore, technical and biological feasabiiiry studies onbiomolecule extraction, plus an integrated marketanalysis, should be initiated.

This study is parl of a larger-scale project on theevaluation and feasibility of extracting high-valuedbiomolecules from residual biomass produced by awolffi sh culture facility.

Objectives

. Characterize the physiological response ofcold re-sistance in both Atlantic and spotted wolffish, and

. Determine the annual pattern ofproduction ofAFp.

Sub-objectives

. Evaluate the influence of fish age and seawatertemperafure on AFP production,

. Evaluate inter- and intraspecific differences in AFpproduction, and

. Measure the effect of AFP production onenergy metabolism.

References

l. Le Frangois NR, Lemieux ll, Blier P. 2002. Aqua. Res. 33:95- l 08.

2. Fletcher GL, Goddard SV, Wu Y. 1999. Chemtech30(6): I 7-28.

3. Hancock, REW. 2000. Opin. lnvest. Drugs 9(8):1723-1729.4. Srmpson BK. Sequerra-Munoz A. Haard NF. lgqq. h: En, v-

cloltedia ol'Food Science oncl Technology, 2nd ed. 1FJ FrancisEditor), Vol.3, p. 1525-1534. John Wiley and Sons Inc. Ny.

5. A/F Protein Canada website http://www.afprotein.com

Nathalie Le Frangois is a researcher at theUniversite du Qubbec c) Rimouski/MAPAQ, CentreAquacole Marin de Grande-Rividre, 6, rue du Parc,Grande-Rividre, Quebec, Canada G)C lV0 (tele-phone 4l 8-385-225 I (222), fax 4 I 8-385-3343,emai I nathal ie. le.francois @),globetro tter. net). PieweBlier is Professor and Head of the Department ofBiology, Universite du Quebec d Rimouski.

Bull. Aquacul. Assoc. Canada 102-2 (2002)

Status of Wolffish Broodstock Studiesin Quebec

Nathalie Le Francois and Jean-Denis Dutil

In 1999, research and development activities on theAtlantic and spotted wolffish (Anarhichas lupus andA. minor) were initiated in Quebec, Canada. There isinterest in these species because of their potentiai usein diversiflring the mariculture industry.

Broodstock wolffrsh collected by local fishermen inthe spring and fall season form two captive wildpopu-lations that are being maintained at Centre AquacoleMarin in Grande-Rividre and at the MauriceLamontagne Institute in Mont-Joli. The populationsconsist of 60 spotted wolffish and 20 Atlanticwo1ffish. At Centre Aquacole Marin, optimization ofthe rearing facilities has made it possible to providethe relatively low temperatures that the broodstock re-quire during the summer months. A method to moni-tor eggs maturation in maturing wolffish females hasbeen developed using echography technology. Thespawning behavior of the female fish has been care-fully observed and documented.

Routine veterinary evaluation of the health of thebroodstock is being done and no outbreaks of disease

Sustaining Members of AAC

Malaspina University-Col1ege

BC Salmon Farmers Association

Office of the Commissionerfor Aquaculture Development

Pacific National Group

Creative Salmon Company Ltd.

Truefoam Ltd.

have occur:red. Cicaterization problems (scarring)have occurred in the fish in the weeks following cap-ture, but in most cases it was adequately controlled.

Several wolffish released eggs in 2000 and 200 1 , butnone of the eggs were ferlilized. Poor egg quality isstrspected to be responsible for the results. In 2002,the broodstocks can be considered to be stabilized andare being maintained in near optimal conditions, in-cluding exposure to seawater temperature that is iessthan 10'C throughout the year. Improvements in theenvironmental conditions in which the broodstock arebeing held are expected to have a positive effect onegg quality and make it possible to pursue upcomingR&D initiatives on the juvenile stages of the spottedwolffish. Cryopreservation techniques have beenevaluatedin orderto stabilize the sperm supply duringfertilization trials. A commercial cryopreservationproduct currently available in Europe has been identi-fied as promising.

Incubation and on-growing ofjuveniles has been suc-cessfully realized using egg masses of Atlanticwolffish obtained from the wild. Currently, over fivehundred 3+ juvenile Atlantic wolffish are being heldin Quebec and a large proportion ofthis captive popu-lation are sexually mature. Fertilization trials on thesefish will be initiated in the coming year.

At this stage, preparation of a majorproposal aimed atthe development of hormonal techniques to followovarian maturation of both species of wolffish is thesubj ect of our efforls to secure funding for wolffish re-search.

Nathalie Le Frangois is a researcher at theUniversiti du Quibec d Rimouski/MAPAQ, CentreAquacole Marin de Grande-Riviire, 6, rue du Parc,Grande-Riviire, Quibec Canada. GOC lVO (tele-phone 4l 8-385-225 I (ext. 222), fnr 4l 8-385-3343,e - mai I nat hali e. I e.franc o is @ g lo b etrott e r. ne t ).Jean-Deruis Dutil is a researcher at the MauriceLamontagne Institute, Fisheries and Oceans Can-ada, Mont-J oli, Quebec.

,

.:i

BulL. Aquacul. Assoc. Canada 102-2 (2002) 23

New Publications

Rural Aquaculture, P Edwards, DC Little, & H De-maine, eds., CABI Publishing, 368p., 2002. Hard-cover, ISBN 0-85199-565-9, US$90.00. Addresseskey issues in aquaculture and rural development, in-cluding case studies from several countries in south-east Asia. Topics range from production and techni-cal issues to social aspects and R&D methodology(www. cabi- publishing. org,&ookshop)

Nutrient Requirements and Feeding of Finfish forAquaculture, CD Webster & CE Lim, eds. CABIPublishing, 2002. Hardcov er, 448p., ISBN 0- 8 5 1 99-519-5, US$140.00. Book provides information onnutrient requirements, feed formulations and feedingpractices ofspecies cultured aroundthe world. Chap-ters have detailed feeding information on specificspecies (www. cabi-publishing.org/bookshop).

Diseases and Disorders of Finfish in Cage Culture,PTK Woo, DW Bruno & LHS Lim, eds. CABI Pub-lishing, 2002. Hardcover, 400p., ISBN 0-85199-443-1, US$149.00. Book is an authoritative refer-ence to infectious and noninfectious diseases ofcoldand warm water finfish in cage culture. Intended foraquaculturists, consultants, pathologists and re-searchers (www.cabi-publishing. org,&ookshop).

Aquaculture and Fisheries Biotechnology, by RADunham, 2002,CABI Publishing. 380 p., hardcover,ISBN 0-85199-596-9, US$100.00. Book gives anoverview of the rapidly advancing area of genetic im-provement of fish for aquaculture and related fisher-ies. Topics covered include polyploidy, sex reversaland breeding, cloning and nuclear transplantation,biochemical genetics, gene mapping, isolation andcloning, transgenic fish, and commercial applica-tions. (website www.cabi-publishing. org/bookshop)

Responsible Fisheries in the Marine Ecosystem, MSinclair & G Valdimarsson, eds., 2002, CABI Pub-lishing. 400p., hardcover, ISBN 0-85199-633-7,US$140.00. Book was developed from an interaa-tional conference in Iceland in October 2001. Con-tents include a globai overview of marine capturefisheries, legal protection for marine ecosystems, andincorporating ecosystem considerations in fisheriesmanagement. (www.cabi-publishing.org,&ookshop).

Fish Hatchery Management, 2"o ed., GA Wede-meyer, ed., American Fisheries Society, 2002.751p.Epanded from the first edition, it includes topics onhatchery operation, production, water issues, trans-portation, stocking, open systems, semi-controlledsystems, broodstocks and spawning, nutrition andfeeding, and fish health. Available from the Ameri-can Fisheries Society (e-mail afspubs@ pbd.com).

Biological Indicators of Aquatic EcosystemHealth, SM Adams, ed.,2002, American FisheriesSociety. 520 p. Book provides information for de-signing and applying bioindicators in the field to as-sess the health of aquatic organisms and ecosystems.For information e-maii afspubs@pbd.com.

Arctic Charr Aquaculture, by G Johnston, 2002,Iowa State University Press. 304 p., hardcover, ISBN0-85238-212-3, US$92.99. Provides the practicaland theoretical information to successfully cultureArctic charr. Gives a general overview of the subject,a practical guide for a producer operating an Arcticcharr farm, and the business of commercially produc-ing Arctic charr. Iowa State University Press (tel 51529 2 -0 1 40, fax 5 1 5 292 -3 3 48, w ebsite isupress. com).

The Icelandic f isheries: Evolution and Manage-ment of a Fishing Industry by Ragnar Arnason,2001, Iowa State University Press. 192p., hardcover,ISBN 0-8523 8-210-3, US$84.95. This book gives anoverview of the Icelandic economy, the developmentphases and position of the fishery. It also discussesthe catching, processing, and marketing aspects oftheindustry and examines the success of the Icelandicfisheries management system. Iowa State UniversityPress. (tel 515 292-0140, website isupress.com).

Conservation of Fresh Water tr'ishes: Options forthe Future, by Maria Collares-Pereira, Ian G. Cowx,& Manuela Coelho, 2002, lowa State UniversityPress. 4'72 p., hardcover, ISBN 0-85238-286-3,US$144.99. Book provides a wide range of viewpoints from specialists around the world on key issuesoffish conservation such as environmental pressures,introduced species, and over-fishing. Iowa State Uni-versity Press (tel 515 292-0140, fax 515 292-3348,website isupress.com).

a/ Bull. Aquacul. Assoc. Canada 102-2 (2002)

Management of Wolffish Broodstock

Helge Tveiten

This article summarises results of srudies on the management of wolffishbroodstock covering several aspects ofthe reproductive cycle ofmale andfemale fish: temperature requirements, photoperiod manipulation of matu-ration and spawning, endocrine regulation, and hormonal stimulation ofsperm production. Exposure of cornmon wolffish (Anarhichas lupus L.) tohigh temperature during ovarian growth (12oC versr-rs 4oC or 8'C) resultedin delayed ovulation, reduced egg productlon, and low egg survival. An in-crease in temperature from 4"C to 8"C or l2'C during the breeding season(time of final oocyte maturation and ovulation) delayed ovulation and re-duced the survival of eggs to the eyed stage from l3o/o at4"C,to 48oh at 8oC,and 8% at 12"C. Sperm quality did not differ between the groups, irrespec-tive of whether fish were exposed to the various temperature treatments dur-ing the sLrmmer months or during the breeding season in late autumn. Com-puter assisted sperm analysis (CASA) was used to examine the motility char-acteristics of spotted wolffish (Anarhichas minor) sperrn. Sperm motilitywas greatest in solutions of 200 to 500 mOsm, decreased rapidly below 200mOsm, and declined more slowly above 500 mOsm. Gonadotropin releas-ing hormone analogue (GnRHa) treatment had little effect on sperm qualityin spotted wolffish. There was, however, a trend for fish given the highestdose of GnRHa to produce active sperm over a longer period of time thanfish in the control group. More than two years of photoperiod manipulationwere required to shift broodstock to a reproductive cycle that was 6 monthsor,rt of phase with the normal breeding period. The effect of photoperiod onthe timing of ovr.rlation was reflected in a coresponding temporal change inplasrna sex steroid hormones.

lntroduction

This arlicle summarises results of studies on thelnanagement of wolffish broodstock carried out at theUniversity of Tromss, Norway. It includes publisheddata and preliminary results from recent experimentson several aspects of the reproductive cycle in bothmale and female fish: temperature requirelnents,photoperiod rnanipulation of maturation andspawning, endocrine regulation, and hormonal stirnu-lation of sperm production.

Effects of Temperature on theReproductive Biology of Common Wolffish

The effects oftemperature on reproductive develop-ment in the common wolffisli were studied in groupsof rnale and female fish subjected to a range of tem-perature treatments during different stages ofthe re-productive cycle. Exposure to high temperature dur-ing ovarian growth (12oC versus 4oC and 8"C) had anegative effect on egg production (lower fecundity

and sn.raller eggs) and egg sr.rrvival (Fig. 1).(r) As aconseqllence, total reproductive oLrtput was reducedin fish exposed to high temperature. Elevated ten-rper-ature also aff-ected the time of fina1 maturation: ovula-tion was delayed by about 4 and 5 weeks in groups offish exposed to 8"C and 12"C compared to the fish inthe 4oC groLrp (Fig. 2). Temperature exposrre causedternporal shifts in sex steroid profiles. In fish exposedto SoC and l2'C, the peaks ofboth testosterone andoestradiol- 17p were delayed by 4 weeks in cornpari-son with those held at 4'C throughout the experiment(Fig. 2).('z) These differences coresponded to shifts intiming of ovulation. The results indicate that repro-ductive endocrine homeostasis in wolffish is influ-enced by temperature treatment during ovarian recru-descence, and that temperature experienced at thisstage of the reproductive cycle also inflr.rences thetiming of ovulation.

Effects of temperature on egg survival were lrorepronounced when fish were exposed to higher tem-peratures during final oocyte maturation and ovula-tion than during ovarian growth. An increase in tem-

Bull. AEracul. Assoc. Canada 102-2 (2002) 25

Figure l. Egg diameter (a), absolute fecundity (b), fertilization rate(c), and egg survival to the eyed stage (d) of common wolffish ex-posed to different temperatures during vitellogenesis. Box-plotsshow average (a-c) or median (d), and the mid, 507o, and 80 % of thevalues. Values that are not significantly different (P > 0.05) sharecommon superscripts. The number of fish in each group is indi-cated above the boxes. [from Journal ofFish Biology 55:809-819]

peratllre from 4oC to SoC or 12oC during the breedingseason delayed ovulation and reduced the survival ofeggs to the eyed stage (from l3o/o at 4oC, to 48o/o at8"C, and 8o/o at12"C) (Figs. 3, +; ;.(3) the high mortal-ity of eggs from fish exposed to I2"C was associatedwith a high incidence of abnormal cell cleavage dur-ing the early stages of development. In eggs from fishexposed to 8"C, the increase in mortality occurred atthe eyed stage and was independent of fertilizationrate and early cell cleavage (Fig. ). Although egg sur-vival decreased with increasing temperature, survivalwas also related to the length of time that individualbrood fish had been exposed to elevated temperaturesprior to ovulation.

Temperature within the range used in our studies didnot have any clear effect on the reproductive per-formance of male fish. Plasma concentrations of sexsteroids associated with spermiation were low (< 2.0ng/ml-) and there was no indication that steroidconcentrations were affected by temperature. Thennmber of spermiating fish, sperm concentration, andsperm motility did not differ between the groups,

12"C

5.0 to 9.0, but was lower at pH 4.5. Sperm motilitywas greatest in solutions of 200 to 500 mOsm, but de-clined above 500 mOsm, and decreasedrapidly below200 mOsm. The unusual characteristics of wolffishsperm may relate to the fish's spawning strategy,which involves mixing of the sperm with eggs that arecontained in a gelatinous mass.

Effects of Gonadotropin Releasing HormoneAnalogue (GnRHa) on Sperm Quality ofSpotted Wolffish

The effects of GnRHa treatment on spenn qualitywere examined by treating sexually mature male fishwith 0 (control), 50 and 150 pg GnRHa,&g grvenintraperitonally in cholesterol pellets containing 5%ococonut butter. Fish were sampled after l, 2, 4 and 6weeks. GnRHa treatment did not result in any signifi-cant change in sperm volume, activity, or density. Infish given the highest dose, however, there was a tran-sient 54% increase in sperm volume after one week.

irrespective of whether fish wereexposed to the temperaturetreatments during the summermonths or during the breedingseason. We did not observe anyeffect of temperature on fertiliza-tion rates, indicating thattemperature did not influence theability of sperm to initiate cellcleavage.

Unusual Characteristics ofSperm of the WolffishAnarhichas minor

Unlike the sperm of most teleosts,those of the wolffish are motile onstripping and can retain activity forat least 2 days. The sperm lose mo-tility when exposed to sea water.Computer assisted sperm analysis(CASA) was used to examine therrrotility characteristics of wolffishsperm. Straight line velocity (vsr-),beat cross frequency (acr), andpercent motility were the most sen-sitive indicators of movement.Sperrn trajectories differed fromthose of other teleosts. Wolffishsperm display large side-to-sidemovements of the sperm head andan irregular trajectory. This may bean adaptation to swirnming in theviscous gelatinous egg mass. Mo-tility was unaffected by pH from

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Figure 2. Timing of ol,ulation (upper panel), plasmaoestradiol-17B concentrations (mean t S.E.) (midpanel), and testosterone concentrations (lower panel)in female common wolffish exposed to different tem-peratures during ovarian recrudescence (a = no differ-ence between groups; b = 4oC different from 8oC andl2oC;c = 4oC and 8oC differentfrom L2"C; d = 8"C dif-ferent from 4oC, but not from 12oC; f = 8"C differentfrom L2'C, but not from 4oC. The number of maturingfish were 14, 18 and 18 in the 4'C,8oC and 12"C groups,respectively. [from Journal of Fish Biology 59:374-3E5]

There was also a hend for fish given the high-est dose of GnRHa to produce active spermover a longer period of time than fish in thecontrol group. Sperm density decreased grad-ually over time in fish from all treatmentgroups.

Year-round Supplies of Eggs and Fry:Using Photoperiod to ManipulateMaturation and Spawning

It is advantageous to be able to manipulatematuration and spawning time so that eggs andfry are produced year-round. Manipulation ofmaturation might also benefit the grow-out ofwolffish if maturation could be prevented andthe reduced flesh quality associated with mat-uration avoided. Our aim was to alter spawn-ing time of the spotted wolffish in an attemptto establish spring and autumn spawningbroodstocks (i.e., 6 months out of phase withthe normal cycle). Under normal light andtemperature cycles the broodfish usuallybreed during late autumn. One group of spot-ted wolffrsh, previously exposed to continu-ous light, was subjected to two seasonal lightcycles compressed into 9 months, and thereaf-ter to a simulated natural light regime. Thisgave a photoperiod regime that was 6 monthsout of phase with that experienced by fish heldunder natural photoperiod conditions. Bothgroups were held at ambient temperature (4"to8"C).

During the first breeding period, after 3 to 4months of photoperiod manipulation, only afew fish ovulated and there was only a smalladvancement in the timing of ovulation in fishexposed to the compressed light cycle. To-wards the end of the second compressed lightcycle, ovulation commenced in July in fishexposed to the compressed light cycles, andthe breeding period was advanced by 3 to 4months compared to that of fish exposed to thenatural light cycle. The effect ofphotopenodon the timing of ovulation was reflected in cor-responding temporal changes in plasma sexsteroid hormones. During the secondreproductive cycle, under which the fish wereexposed to a simulated natural light cycle 6months out of phase with the natural lightregime, ovulation started in April, 6 monthsearlier than in fish exposed to a natural lightcycle.

Thus, over 2 years of photoperiod manipula-tion were required to establish broodstockshowing 6-month shifts in the timing of the

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Bull. Aquacul. Assoc. Canada 102-2 (2002) 27

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breeding period. The effectof photoperiod ffeatment isexpected to be influencedby the photoperiodic historyof the fish, the direction ofchange of photoperiod, andthe timing of photoperiodicchange relative to the stageof the reproductive cycle.As such, it may be possibleto establish broodstocks thatspawn out-of-phase witheach other using photoper-iod manipulations of shorterduration, but this remains tobe investigated.

This study forms part ofproject numbers108087/120 and1 4 1 77 5/1 20 supported bythe Norwegian ResearchCouncil.

References

1. Tveiten H, Johnsen HK.1999. J. Fish Biol.55:809-8 19.

2. Tveiten H, Solevag SE.,Johnsen. HK. 2001 . "f.Fish Biol.58: 374-385.

3. Tveiten H, Johnsen HK.2001. J. Fish Biol.59:374-385.

Helge Tveiten is aresearcher at theInstitute ofAquatic Re-sources and Envi-ronmental Biol-ogy, NorwegianCollege of FisheryScience, Univer-sity of Troms/,Breivika, N-9037Tromsl, Norway(telephone 47 7764 60 00, far 4777 64 60 20,email helget@nft.uit.no).

60

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Figure 3. Influence of temperature experienced during the spawning seasonon the cumulative percentage of ovulated female common wolffish overtime. [from Journal of Fish Biology 58:374-385]

4"C 8"C 12"C 4'C 8'C 12'C

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Survival to theeyed stage

Figure 4. Fertilization rate (mean t SE), and percentages of normally cleaved eggs, sur-vival of eggs to the eyed stage and to hatch from female common wolffish exposed to dif-ferent temperatures during the spawning season (n=10, 10 and 9 in the 4'C, 8oC and12'C groups, respectively). Eggs were incubated at a temperature of 6"C. Values thatare not significantly different (P > 0.05) are given common designation. [from Journalof Fish Biology 58:374-3851

28 Bull. Aquacul. Assoc. Canada 102-2 (2002)

Factors Affecting Survival and Growthof Early Life Stages of Spotted Wolffish

(An arh i chas m i nor Olafsen)

I.B. Falk-Petersen

Incubation temperature affects egg developmental rate, yolk consumption,incubation time, and survival, and final size and survival of spottedwolffishlarvae. The highest survival during egg incubation, hatching, andstart-feeding occurred in egg batches incubated at constant 6'C. The size ofnewly hatched larvae was positively correlated with initial egg size and thelargest larvae hatched from eggs incubated at 4'C. Hatching may represent acritical phase: both premature and postmature hatching result in high mor-tality during early larval life. Disinfectants affect egg survival and thehatching process. Handling or transportation influence egg survival and theearly egg stages are the most sensitive to such stress. Strong light is detri-mental to eggs. The 2l-24 mm well-developed larvae start feeding on for-mulated feed and Artemia soon after hatching. Mortality duringstart-feeding varies between batches and with temperature, and is related tothe temperature during egg incubation and the disinfection procedure usedon the eggs. The highest survival during start-feeding was registered at SoC(96%) in groups originating from eggs incubated at 6oC. Initial daily growthrates were highest at both l2"C atd l4'C. A newly-developed formulatedfeed increased survival and growth of larvae and early juveniles comparedto those reared on various other commercial feeds andArtemia sp. The com-mercial feed Marin nutra (Skretting) also produced high growth rates andgood survival during the start-feeding period.

lntroduction

The spotted wolffish Anarhichas minor Olafsenwith its rich and tasty fillets, popular skin, and rapidgrowth rates in captiviry, is a promising candidate forcold-water aquaculture. A production line for spottedwolffish has been established based on several yearsof active research on the biology of the species at theNorwegian College of Fishery Science, University.o.fTromsi, in cooperation wiih R&D companies.(l-*)Wolffishes were introduced as potential new speciesfor cultivation l5 years ago andbiological studies onthe common wolffish (A. lupus) were initiated.Growth rates of the spotted wolffish appear to bebetter than those of the common wolffish,{')so the fo-cus has now changed.In1992193, we collected adultspotted wolffish from the Barents Sea and establisheda broodstock at the Aquaculture Research Station,University of Tromss. The first eggs hatched in 1994and the offspring from this and later generations arenow contributing to the broodstock population atTroms Steinbit A/S, the only egg and juvenile produc-

tion plant established in our area.(l)Successful production of high quality eggs and lar-

vae depends upon favourable environmental condi-tions for the broodstock as well as during the longegg-incubation phase, the start-feeding phase and theearly growth phases. Wolffish juveniles can bestocked at high densities in shallow raceways andthey grow well under favourable conditions.(6-8)Un-der culture conditions the fish are apparently social,despite the fact they are probably territorial duringmost of the year in nature. Wolffish broodstock havebeen fed both salmon and marine fish feed, but the re-cent development of a more optimal formulatedfloating dry feed has given promising results.

Broodstock individuals collected from the BarentsSea, and their offspring grown in the facility, have anapparently normal reproductive cycle in captivity.The spawning season extends from July until January,with spawning occurring primarily in October andNovember in fish kept at normal seasonal seawatertemperature (varying from 3"to 10"C) and daylength.(t) The spawning period can be extended with

Bull. Aquacul. Assoc. Canada 102-2 (2002) 29

photoperiod manipulation of the reproductive cycle.Temperatures that are too high during the final phaseof oogenesis may effect egg quality. In addition, hightemperatures may induce outbreaks of atypicalfurunculosis (caused by Aeromonas sp.).

Temperature is the major factor influencing the de-velopmental rate and survival of fish, and optimal en-vironmental conditions are important for successfulcultivation.(e) Yolk is generally utilized faster athigher temperatures. The efficiency with which yolkis transformed into body tissue and the effect of tem-perature on yolk utilization probably are importantdeterminants of early survival. The presentprojecthasfocused on the survival and developmental biology ofeggs incubated at various temperatures, the hatchingperiods and survival oflarvae hatching at different de-velopmental stages,{o) the efficiency of various eggdisinfectants and concentrations,(r0)as well as experi-ments with various start feeds and start-feeding tem-peratures.(3'a) In addition the sensitivity of the eggs tomechanical disturbance (transport) at various devel-opmental stages has been investigated and a few ex-periments have been carried out to study the effects oflight intensity during egg incubation.

Materialand Methods

Shortly after ovulation, female wolffish werestripped and the eggs were fertilizedby careful mixingwith sperm from one to three males. Fertilized eggswere left for 4 to 6 hours before being transferred to20-L upstream incubation units, 2-L experimentalunits or larger raceway incubation systems. Eggs werecarefully spread apart to prevent them from stickingtogether. The 5- to 6-mm eggs were incubated at vari-ous temperatures in darkness and routinely disin-fected for 5 minutes with 150 PPmglutaraldehyde.('''o) The fertilized eggs were trans-fened to incubation units in triplicate or duplicategroups. They were held at selected temperature re-gimes from 2o to SoC, treated with various concentra-tions of disinfectants, and incubated at high or lowlight intensities. Mortality, yolk utilization, develop-ment rate, hatching success, larval size, first-feedingsuccess, and growth of larvae were recorded. Deadand decaying eggs were noted and removed at fre-quent intervals.

Spotted wolffish larvae arc 21-24 mm long and welldeveloped when they start feeding soon after hatch-ing. They accept formulated dry feed as well asArtemia (or combinations of the two). Larvae weretransferred to shallow mini-raceways for start-feedingexperiments at various temperature regimes usingboth commercial and "new" feeds.

Results

I n cub ati on te m pe ratu re

Good egg batches have shown - 100% fertilizationrate and survival rates have been between 60 and 80%during the 800 to 960 degree-day (dd) incubation pe-riod.(r-a) The low fertilization rates in some eggbatches presented a practical problem as the eggs de-generated and became infested with bacteria. Fertil-ization problems occurred in some cases when the eggquality was generally good.

The survival ofeggs during the long incubation pe-riod was significantly different between groups at thethree incubation temperatures and was best in batchesincubated at constant 6oC (1-4) or at ambient tempera-tures which decreased from 6-8oC to 3oC duringincubation. A constant temperature ofSoC also gavegood results, while low temperature (constant 2'C)was disastrous, and results from 4oC have been vari-able. Most of the egg mortality occurs during the pe-riod from 150 to 300 degree-days. In some cases,there also has been high mortality during the hatchingperiod; postmature hatching often results in dead em-bryos or low survival immediately after hatching.

Incubation time decreased with increasing tempera-ture, but the number of degree-days required for com-pletion of egg development increasedwith increasingtemperature.(l-4) Time to the peak hatching period was

- 940 dd (17 weeks) at 8oC, -910 dd (22 weeks) at6"C and -850 dd (30 weeks) at 4"C. Morphologicaldifferences reflecting variations in differentiationwere noted among larvae originating fiom the differ-ent temperature groups. Transfer of yolk to embry-onic tissue appeared to be most efficient at 4"C.(4) Sizeof the visible yolk at peak hatching otherwise variedbetween egg batches and also with temperature. Thelargest larvae hatched from the eggs incubated at thelower temperatures.(a)

Some egg batches developed more synchronouslythan others. Within each batch, hatching took placeover several weeks, but there was always a relativelysharp peak in hatching from which most of the viableoffspring recruited. Premature hatching may be in-duced in eggs resting in microzones with low oxygentension. Temperature elevations, short disruptions inthe water supply, or mechanical disturbances also in-duced premature hatching. Lowering the temperaturefrom 8'C to 6'C has in some cases inhibited hatchingin batches with such tendencies. In addition to the sizeand weight differences caused by incubation tempera-ture there is an increase in embryo length and particu-larly weight with time of hatching.(rr)

30 Bull. Aquacul. Assoc. Canada 102-2 (2002)

Egg disinfectants

Disinfection of eggs with 150 ppm glutaraldehydefor 5 minutes the first day after fertilization and there-after once or fwice per month until -600 dd increasedsurvival until hatching.(1-a) Treatment with 300-1200ppm glutaraldehyde twice per month increased sur-vival during the egg phase, but inhibited hatching andresulted in 87-100 o/o mortality, compared to -60 ohmortality, but normal hatching, in untreated controls.Treatment with the iodophor buffodin (1.5-2%) alsoreduced mortality during incubation and did not in-hibit the hatching process.('')

The frequency ofdisinfection also affected survivalof eggs. Disinfection twice a month appeared to im-prove survival until hatching at the temperaturestested.(11) There was a tendency towards higher num-bers of prematurely hatched larvae in eggs disinfectedtwice a month compared to those ffeated once amonth. The survival curves reflected a combination ofeffects caused by incubation temperature and disin-fection frequency. Survival was lowest at the lowestincubation temperature (4"C).

Mechanical disturbancesand light intensity

Morlality during the egg stage and at hatching wasalso caused by mechanical disturbances during theearly incubation period. The eggs were.most sensitiveduring early cleavage and gastrulation.( ") Exposure toconstant high light intensities during incubation re-sulted in total mortality of the eggs within the firstmonth and medium light intensities resulted in verylow survival at hatching.

Feedingand temperature

Wolffrsh larvae can be fed formulated feed particlesimmediately after hatching. A newly developed for-muiated feed produced by H.K. Strand,Fiskeriforskning (feed based on fish liver residues,squid meal, immunostimulants, attractant, vitaminsand binders (alginate/dextrin)) has increased survivaland early growth of both common and spottedwolffish compared to some commercial feeds andArtemia sp.(e'r) 11r. commercial feed Marin nutra(Skretting) has also resulted in high growth rates andgood survival, and a newly tested feed from Danafeedhas shown even more promising results.

Experiments on start-feeding of larvae held at vari-ous temperatures (6o to 16' C) showed that larvalgrowth rates increased with temperature up to l4oC,but survival was lower at the higher temperatures. Inone experiment, mean wet weight and mean survival

of spotted wolffish larvae 0-63 days post-hatchingwere compared among groups fed dry feed (commer-cial marine fish feed from Skretting) at ambient sea-sonal temperature and constant temperatures (6o, 8o,1 0o and I 2"C). Growth was best at I 2'C, but mortalitywas significantly higher at this temperature. In an-other experiment, mean wet weight and mean sur-vival were compared during 0-63 days post-hatching,fed dry feed at variable temperatue regimes (the first30 days constant temperafures of 8o, 1 0o, 12o, 14" and16oC were used, thereafter all groups were regulatedto constant 8'C). Individual growth rates increasedwith increasing temperatues up to l4'C, but at 16oCgrowth was retarded. Survival was low in both the16'C and l4"C groups, intermediate in the l2'C and10'C groups, and best in the 8'C g.oup.(')

In general, yolk reserves are completely exhaustedafter -3 weeks in feeding larvae. After 4 weeks mostnon-feeding individuals are dead. The number of un-successful feeders varied between batches and thereasons for the variations are obscure. Early survivalhas b een between 8 0% and 9 6Yo in the best group s. (7)

Temperature historyof eggs

Water temperature during egg incubation affectedsubsequent larval growth and survival. Studies ongrowth of spotted wolffish larvae hatched from eggsincubated at different temperatures (4", 6" and 8"C)showed that early growth from hatching until 42 dayspost-hatching at SoC was better in the groups originat-ing from eggs incubated at the lower temperatures.Survival during firslfeeding was highest among lar-vae originating from the 6"C group, and lowestamong those from the 8'C group.(')

Hatching time

Mortality during the 10 weeks of start-feeding washigher among prematurely and postmaturely hatchedindividuals.(10)

Histological studies

Wolffish larvae hatch at an advanced developmentalstage with apparently functional organ and tissueanatomy and histology.(r4-r6) Histomorphologicalstudies of developing larvae have been conducted inconnection with various feeding experiments. Cleardifferences were noted in liver histology and subcuta-neous and intramuscular fat accumulation in wolffishlarvae fed various diets and rations.(6'17)

Bull. Aquacul. Assoc. Canada 102-2 (2002) -tl

Cooperation Model

I would like to point to the successful cooperationmodel among R&D partners in Tromso (TromsSteinbit Ltd., Akvaplan-niva, NFH/ University ofTromso, Norwegian Institute of Fisheries andAquaculture Ltd.), which efficiently has brought cul-tivation of spotted wolffish to its present stage. Con-tributions and expertise ofthe partners are:. Reproductive biology, eggs and larvae (I.IFH, Uni-

versity of Tromss, Troms Steinbit). Fish health Q.Jorwegian Institute of Fisheries and

Aquaculture and NFH, UiTo; Troms Steinbit). Fillet quality (NFH, UiTo; Troms Steinbit). Marketing (NFH,UiTo, Norwegian Institute of

Fisheries and Aquaculture Ltd., Eksportutvalgetfor fisk, Akvaplan-niva, Troms Steinbit

There have been regular seminars for