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JOURNAL OF THEWORLD AQUACULTURE SOCIETY

Vol. 32, No. 1March, 2001

Reproductive Performance of Macrobrachium rosenbergiiFemales in Captivity

RONALDO O. CAVALLII , PATRICK LAVENS, AND PATRICK SORGELOOS

Laboratory of Aquaculture & Artemia Reference Center, Ghent University, Rozier 44,Ghent 9000 Belgium

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Abstract.-The breeding frequency, fecundity, egghatchability, larval output and viability of pond-reared,mature Macrobrac:hiwn ro.~enbergii females were in-dividually followed up during l80 d. Sexually matureprawns were maintained under controlled laboratoryconditions (28.7 C and 12-h ligh£ld) in a 190-L fresh-water recirculation system and fed a formulated diet.Ovarian development. moulting and spawning eventswere checked daily. At least six consecutive moultswere recorded for each of the l8 females. The duration

of the intermoult period averaged 27.5 d and was notaffected by ovarian development or spawning, but in-termoult periods followed by spawning had signifi-cantl:l' lower growth rates. From a total of 126 moult-ing events recorded, egg laying successfully followed76 (60.3%) of them. The number of eggs per spawn(NES) varied from 26.587 to 74,775 for femalesweighing 20.0 to 55.8 g. The relationship betweenNES and female size (W; in g) was found to be NES= 484 + 1454W (rl = 0.74). Results suggest that thenumber of viable larvae produced per egg clutch maybe increased by in vitro incubation. as the losses ofeggs, which usually occur under in vivo incubation. areprevented. The present study illustrates that under ad-equate and stable rearing conditions, M. rosenbergiifemales are able to spawn up to five times during 180d, in comparison to three to five times per year asreported for wild prawn populations.

The freshwater prawn Macrobrachiumrosenbergii is native to the Indo-West Pa-cific region (Holthuis 1980), but because ithas several characteristics considered to be

appropriate for culture, it has been trans-ferred to almost every continent. To date,the culture of M. rosenbergii either forcommercial purposes or research activitieshas been reported in a total of 77 countries(New 1995). Prawn farming has consider-able economic importance, particularly inAsia (China, Thailand, Vietnam, Taiwan,

I Corresponding author's present address: Funda~aoUniversidade Federal do Rio Grande, Departmento deOceanograt1a. CP 474. Rio Grande, RS 9620l-900"Brazil.

Bangladesh, and India) and in Latin Amer-ica (Ecuador and Brazil). World productionin 1997 was estimated at 60,995 metric tons(FAO 1999).

Hatchery production of M, rosenbergiipostlarvae requires reliable sources of egg-bearing females. For many hatcheries lo-cated in tropical regions, year-round avail-ability of larvae is guaranteed by the use ofegg-bearing females obtained from cultureponds or, within the natural distributionrange of this species, from rivers, lakes andestuaries. Under temperate and sub-tropicalconditions, however, the usual practice is toselect adult males and females during fallharvests and to maintain them indoors intemperature-controlled environments dur-ing winter. Unfortunately, although several

-'studies provided valuable information re-garding broodstock management (Ling1969; Wickins and Beard 1974; Chow1982; Malecha 1983; O'Donovan et al.1984; Chavez Justo et al. 1991; Damrong-phol et al. 1991; Daniels et al. 1992), amore fine-focused approach dealing specif-ically with the performance of captive M.rosenbergii broodstock has not been con-sidered. In addition, to our knowledge nodata on the frequency of spawning and re-maturation of individual female prawns isavailable. Furthermore, with the exceptionof Wickins and Beard (1974), most studiesfailed to provide information on the repro-ductive performance of captive stocks.

The present paper reports on the breedingfrequency, fecundity, hatching rate, larvaloutput and viability of a pond-reared stockmaintained under strictly controlled labo-ratory conditions for 6 months. The resultsare discussed in relation to those availablefrom field and laboratory studies.

o Copyright by the World Aljuaculture Society 21XJI

60

REPRODUCTIVE PERFORMANCE OF fHACROBRACHIUM 61

TABLE I. Compositiol! of the experimental diet (% dry weight).

a Sigma. USA.b Rieber & Son. Norway." Protein Technologies International. Belgium.

d Vandermoortele. Belgium., E50. Inve Aquaculture. Belgium.

f Primex. Norway.

g Roche. Belgium.

h Emulpur N. Lucas Meyer. Germany.

, Federa. Belgium.

Materials and Methods

Origin of Animals

Adult M. rosenbergii obtained frompond-reared sources in Thailand were trans-ported to the Laboratory of -Aquaculture,Ghent University, Belgium. After arrival,prawns were gradually acclimated to 28 C.They were maintained in a freshwater re-circulation system at 28 C and a 12-h light!12-h dark photoperiod for 2 mo before thebeginning of the experiment. During thisperiod they were fed a shrimp broodstockdiet (Inve Technologies N.V., Belgium). Atthe beginning of the experiment, all femaleswere sexually mature and males were of theblue-claw (BC) morphotype (Kuris et al.1987). Wet weight and total length of thefemales were 26.2 :t 5.1 g and 14.5 :t 5.7cm, males were 40.2 :t 5.2 g and 15.5 +

1.1 cm, respectively. '-

Experimental Conditions

Prawns were maintained in three separaterecirculation units, each containing one

150-L holding tank and one 40-L biologicalfilter. To allow the individual follow up offemales, the holding tank was divided intonine compartments, each housing one Ma-crobrachium adult (total of six females andtwo males per tank). The ninth compart-ment contained the water evacuation pump.Approximately 20% of the water was ex-changed daily after the removal of wastesand uneaten feed. During the experiment,the' levels of NH4+-N; N02-N and NO)"-Nwere kept under 0.2, 0.06 and 100 mgIL,respectively. Freshwater was maintained at28.7 :t 0.8 C and the photoperiod was setat 12-h light!12-h dark (Chavez Justo et al.1991). Three 18-W fluorescent lampsplaced 0.9 m above the water level of eaChholding tank provided a light intensity of600 Ix. An additional group of males waskept under similar conditions. Theseprawns replaced any male that died duringthe course of the experiment.

A formulated diet (Table 1) containing

44% crude protein and 9% total lipids was

Ingredients % Ingredients %

Casein" 15 Attractant (protein extract)f 3.6Lobster mealh 14 Starch" 22.82Soy protein isolate" 8.75 Cellulose" 1.82

Squid mealh 5 Kappa-carrageenan" 5Shrimp mealh 2.5 Astaxanthin 1.25Crab mealb 2.5 Cholesterola 0.6Threoninea 0.8 De-oiled soy lecithinh IValinea 0.65 Choline chloride" I

Lysinea 0.9 Mineral mix' 4Histidine" 0,45 Vitamin mix' 2

Argininea I Ascorbyl polyphosphate 0.27Leucinea 0.4 dl-a-tocopherol acetate' 0.04Iso-Ieucinea 0.16 Butylated hydroxy toluene' 0.005

Soybean oild 2.15 Butylated hydroxyanisole' 0.005Fish oil' 2.33

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62 CA VALL! ET AL.

offered in excess twice a day (0930 and1800). Every morning excess feed andwastes were siphoned out, and aerated andpre-heated freshwater was added to refillthe experimental units. At the same time<the occurrences of moults and mortalitywere recorded.

..

Evaluation Parameters

Ovarian development, moulting andspawning events were checked daily over180 d. Ovarian development was classifiedaccording to colour, size, and outline of theovaries as described by Chang and Shih(1995). Provided that the newly moulted fe-male had developed ovaries, it was isolatedwith a hard-shelled male for mating during3 h. Seven days later, eggs were manuallyremoved from the abdomen of the female.

The total (somatic) wet weight of the fe-males was then assessed after blotting. Sim-ilarly, prior to weighing, the excess surfacewater from the egg clutch was removed byblotting. Three egg sub-samples wereweighed and counted to det~rmine the totalnumber of eggs per clutch:

Moults were classified as non-reproduc- /

tive moults, if during the intermoult periodno ovarian development occurred, or pre-mating moults, if mating and egg layingfollowed. The duration (D; in d) and theinstantaneous growth rate (G = (lnW:! -InWI)/(T:! - TI); where WI and W:! =weight at time TI and T:!, respectively) ofthe intermoult periods preceding non-repro-ductive and pre-mating moults were evalu-ated.

Egg Hatchability

Hatching rates were estimated in vitro in200-mL glass cones. A single egg clutch,weighed to contain 100-200 eggs, was add-ed to the hatching cones. Natural (33 gIL)seawater diluted to 6 gIL with deionisedwater was exchanged daily with pre-heatedwater. Water temperature was 28.2 :t 1.1 Cand gentle aeration was provided. The eggswere not disinfected throughout the incu-bation period. The hatching rate was deter-

mined byand dead

hatching.

counting the number of larvaeeggs approximately 24 h after

Larval Viability

Larval viability was estimated by cultur-ing newly hatched larvae for 8 d. The larv-iculture set-up consisted of six 20-L cylin-der-conical tanks connected to a single re-circulation system containing a settlementsump and a submerged biological filter witha volume of 125 L. An upwelling systemwith a water flow rate of 0.33 L/min was

used and gentle aeration was applied to allrearing tanks. Fluorescent lamps provided750 Ix at the water surface for 12 hid. One

thousand newly hatched larvae from eachspawn were transferred into one tank (den-sity of 50 per L). Sea water was diluted to12 g/L with deionised water and maintainedat 28.0 :t 1.0 C. Artemia franciscana nau-plii (Great Salt Lake strain) were offered ata density of 10-15/mL from day 2 to day7. On day 8, the culture was terminated andthe surviving larvae were counted.

Statistical Analyses

Duration of the intermoult periods, therespective growth rates, and reproductiveperformance parameters were analysed byanalysis of variance (one-way ANOVA)and, where appropriate, Tukey's honest sig-nificant difference (HSD) test was applied.Differences were considered to be signifi-cant at 5%. In an attempt to identify thefactors responsible for differences in repro-ductive performance, regression analysis offemale size against the number of eggs pro-duced per spawning event and per femalebody weight was also performed. All dataare presented as means :t SD.

Results

From the 18 females stocked, three

deaths were recorded, which represented asurvival rate of 83.3%. Males suffered a

higher mortality rate. From the six malesinitially stocked, five died during the courseof the experiment, resulting in a survival

- --- ----

1 ...REPRODUCTIVE PERFORMANCE OF MACROBRACHlUM 63

TABLE2. Reproductive perfonnance ofM. rosenbergiifemales maintained in captivity for 180 d according totheir spawning order. Within rows, superscript letters indicate significant differences (P < 0.05).

rate of only 16.7%. A high mortality ofmales was also observed during the accli-mation period. A few days preceding death,males appeared weak, lethargic, stoppedfeeding, and were unable to maintain bodyposture. Epibiont fouling of the carapacewas also noticed.

The experimental design enabled us toindividually follow the reproductive cycleof M. rosenbergii females during at least sixconsecutive intermoult periods. Femalestook an average of 27.5 :t 4.7 d to moult.

Egsisp."" -41.3.'.+ ,.s.t W

(,'-0.74)I

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Female weight (g)

B Eusla - I WJJI - 6.016 BW

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Female weight (g)"-

FIGURE1. Regression lines and respective 95% con-fidence limits betWeen female body weight (W) andnumber of eggs per spawning event (A), and numberof eggsper female body weight (B).

Although no significant difference in theduration of the intennoult periods in rela-tion to the preceding moult was detected(26.8 :t 4.8 and 28.0 :t 4.3 d for the non-reproductive and pre-mating moults, re-spectively), the instantaneous growth ratewas significantly higher in non-reproduc-tive moults (4.43 :t 1.97 mg/d) than in pre-mating moults (2.61 :t 1.62 mg/d).

From a total of 126 moulting events re-corded, 76 of them (60.3%) were associatedwith reproduction, i.e., an egg clutch wasobserved on the abdomen of the females 1

or 2 d after moulting. The average numberof spawns per female during the experi-mental period was 4.2 (:t 1.2), whereas fivefemales were able to spawn five times dur-ing the course of the experiment (Table 2).However, the females did not retain allclutches. From the 76 clutches observed, 13

(17.1 %) were lost 1 to 3 d after spawning.The number of eggs per spawning event

varied considerably between individuals,ranging from 26,587 to 74,775 eggs (meanof 46,512 :t 11,220 eggs). The number ofeggs per spawn increased significantly withfemale size (Fig. lA) and spawning order(Table 2). The relationship between thenumber of eggs per spawning event (NES)and female size (W; in g) was found to beNES = 484 + 1,454 W (r = 0.74). Theregression between female size and eggproduction efficiency (number of eggs perfemale weight; eggs/g) resulted in a low re-lationship coefficient (r = -0.04; Fig. IB).

Spawning order I II III IV V

Number of spawns retained 18 17 12 11 5Eggs per spawning event 40,466 b 46,428 ab 50,229 ab 47,604 ab 57,238 a

::!:7.963 ::!:11,724 ::!:10,435 ::!:9,588 ::!:15,803Eggs per female weight 1,466 1,424 1,528 1.338 1.519

(eggs/g) ::!:160 ::!:246 ::!:163 ::!:239 ::!:193Hatching rate 83.2 82.4 86.3 87.3 97.7

(%) ::!:14.4 ::!: 18.9 ::!:8.6 ::!:8.1 ::!:2.2

Larval survival to day 8 86.1 89.0 89.1 92.3 89.8(%) ::!:9.3 ::!:6.8 ::!:9.6 ::!:6.1 ::!:5.4

80000 ,

70000A

c60000

..c. 50000"5i.... 40000101

30000

2200

2000

'800

'600

'400....101 '200

'000

800

80015

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The number of eggs per female }Veightwasnot significantly affected by spawning order(Table 2).

From the 63 spawns incubated in vitro,four groups of fertilised eggs were discard-ed because of high accumulation of debrison the surface of the eggs probably due tobacterial and/or fungal infections, and fivedid not hatch due to the lack of aeration

overnight. The remaining 54 groups of eggsresulted in viable larvae. Mean hatchingrates were consistent and always above82%. Egg hatchability did not vary signif-icantly with spawning order (Table 2). Sur-vival of larvae after 8 d of culture was alsorelatively high (Table 2), ranging from70.0% to 100% (overall mean of 89.1 % +

8.0%).

Discussion

Development in sexually mature M. ro-senbergii females involves the physiologi-cal processes of moulting, somatic growth,and ovarian development. If somaticgrowth dominates developJIlent, intermit-tent, non-reproductive moults take place.When ovarian development is emphasised,--a pre-mating moult is followed by matingand egg laying (Ling 1969) and, as a con-sequence, somatic growth is sacrificed atthe expense of ovarian development. Ac-cordingly, a decline in the growth rate offemales entering sexual maturity is often re-ported (Ra' anan et al. 1990; Chavez Justoet al. 1991) and agrees with our observationthat intermoult periods followed by egg lay-ing had decreased growth rates.

In the natural environment, M. rosenber-gii may spawn 3 to 4 times per year (Ling1969) or more than 4 times (Rao 1991).Wickins and Beard (1974) reported that onefemale maintained in captivity spawned 4times in 170 d, indicating the reproductivepotential of this species when maintainedunder appropriate rearing conditions. Thisis in line with our results, where femalesdemonsti-ated a capacity to breed up to 5times over 180 d. Differences in female size

between these studies probab~y partially ex-

plain the differences in breeding frequency,but one can assume that stable, optimal en-vironmental conditions and a more bal-anced nutrition may also play a significantrole. Furthermore, the fact that the eggs

. were removed may also have a positive im-pact on the performance of the females,possibly through an increase in breedingfrequency (Pandian and Balasundaram1982; Damrongphol et al. 1991).

Within a group of sexually mature M. ro-senbergii females, not all moulting eventsare associated with reproduction. Damrong-phol et al. (1991) stated that most maturefemales emphasise ovarian development,but not all moults are followed by a recep-tive period. Similarly, in our study femalesset priority for reproduction, and 60.3% ofthe moults were followed by mating andegg laying. This is in accordance. with Gra-ziani et al. (1993), who observed that60.6% of the moults of captive Macro-brachium carcinus females were followedby egg laying, and Pandian and Balasun-daram (1982), who reported that 61% of M.nobilii females spawned following a moult.However, the occurrence of consecutivebreeding is known to vary seasonally. WildM. rosenbergii females from India showedpeak reproductive activity during the sum-mer months of August to October (Rao1991). Similarly, 90% of M. rosenbergii fe-males collected in Israeli ponds during thewarmer breeding season were observed tocarry eggs (O'Donovan et al. 1984).

Some females dropped the eggs 1-3 dafter spawning, indicating the lack of fer-tilisation (Ling 1969; Wickins and Beard1974). The reasons for this are not clearlyunderstood, but it might be that the timespan between the pre-mating moult andmating was not adequate. Ling (1969) re-ported that newly moulted females are re-ceptive to males from 3 to 6 h after the pre-mating moult, while Chow (1982) foundthat receptivity for artificial inseminationlasts for 10 to 15 h following a pre-matingmoult. It is possible that when females andmales were placed together the. receptive

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REPRODUCTIVE PERFORMANCE OF MACROBRACHIUM 65

period had already occlHTed. Other possibleexplanations include the disturbance causedby human presence or the incapacity ofsome males to successfully mate or to pro-duce quality sperm.

A high mortality of BC males was ob-served in this study. Prior to death, malesappeared weak, displayed a lethargic be-haviour, their carapaces were covered withepibionts, and they were unable to maintainbody posture. Similar symptoms have alsobeen reported by Daniels (1993). Brock(1993) suggested that the mortality of pond-reared BC males might be due to a terminalanecdysis termed "terminal growth." In itsadvanced stage of development, males with"terminal growth" would present symp-toms similar to those presented by our BCmales. Daniels et al. (1992) recommendedthat both sexually active BC males and or-ange-claw (OC) males should be stocked tooffset the mortality rate of males that occurover a long holding period in captivity.Though OC males have no immediate re-productive role, they will eventually turninto a BC male, which represents the finalstage of male development.

The efficiency of egg production, i.e., thenumber of eggs produced per female unitbody weight, may be age a..ndJorsize de-pendent and is generally assumed to in-crease with female size (Malecha 1983). Inour study, the efficiency of egg productionwas found not to be significantly affectedby female size. Costa and Wanninayake(1986) and Rao (1991) reported that in wildpopulations of M. rosenbergii froII1-SriLan-ka and India, respectively, smaller femalesproduced a higher number of eggs per unitbody weight. A similar trend has also beendemonstrated in the shrimp Penaeus mon-odon (Villegas et al. 1986). In contrast, Pa-tra (1976), Ang and Law (1991) and Cavalliet al. (2000) found that the number of eggsper body weight increased with M. rosen-bergii female size. Therefore, as severalstudies present contrasting results, the effi-ciency of egg production clearly remains asubject of investigation. Essential subjects

on this line of studies are, for instance, toinvestigate environmental, genetic, and nu-tritional factors that might cause differentpatterns of body size-fecundity relation-ships. The efficiency of egg production infemales of different size classes will surelydepend on several of those factors.

From a reproductive perspective, the se-lection of smaller females for hatchery usemight be considered an advantage, as theyhave a higher moulting frequency, hence ahigher breeding frequency, and perhaps amore efficient egg production. However,even if smaller females were more efficient

in terms of egg production per body weight,in a hatchery situation the production ofeggs per unit time is crucial. Consequently,hatchery operators usually select the largerfemales for reproduction because fecundityis linearly related with female weight, asclearly demonstrated in several studies (Pa-tra 1976; Malecha 1983; Costa and Wan-ninayake 1986; Ang and Law 1991; Rao1991).

While the number of freshly laid eggs perfemale represents its "realised reproduc-tion," the number of eggs in late stages ofdevelopment is closer to the "actual repro-duction," i.e., the number of larvae pro-duced. The latter is usually lower amongcarideans (Corey and Reid 1991). For cap-tive M. rosenbergii, Wickins and Beard(1974) suggested that egg losses during invivo incubation could amount to 31% of theeggs initially deposited in the brood cham-ber. Malecha (1983) observed that egg-car-rying females maintained in ponds had alower fecundity than those maintained inthe laboratory. Ang and Law (1991) alsodemonstrated that under pond conditionsfemales present a decrease in the number ofeggs with incubation time. Egg losses..wereconsidered to be partially due to their con-sumption by females, to the continualsloughing off of dying eggs due to epizo-otic infestations and to the loose nature ofthe larger grey eggs, which would renderthem more prone to physical losses. Pre-venting the decrease in egg numbers by

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66 CA V ALL! ET AL.

manually collecting them after spawningfollowed by in vitro incubation might in-crease the number of larvae released from

an egg clutch. For instance, our resultsshow that around 1,450 eggs can be pro-duced for each gram of female weight.Considering a hatching rate of 86%, itwould be possible to obtain around 1,250larvae per gram of female body weight.This procedure would mean a substantialincrease over the 1,000 or 450 larvae pergram of female weight proposed by Newand Singholka (1982) and Malecha (1983),respectively. The advantages of applyingthis methodology consist not only in the po-tential increase in the number of larvae pro-duced, but also in relieving females fromthe task of incubation, which increases theirreproductive output by an increased breed-ing frequency, as demonstrated for M. no-bilii (Pandian and Balasundaram 1982) andM. rosenbergii (Damrongphol et al. 1991).

However, the use of in vitro incubationmight also present some constraints. Al-though eggs of Macrobrachium have al-ready been successfully incubated under .-various systems and conditions (Balasun-daram and Pandian 1981; Mathavan andMurugadass 1988; De Caluwe et al. 1995;Das et al. 1996; Cavalli et al. 1999), the riskof microbial infections increases becausenon-viable eggs, which are usually lost dur-ing in vivo incubation (Malecha 1983; Angand Law 1991), are retained in in vitro in-cubation. Furthermore, anti-microbial se-cretions, thought to be produced by the in-cubating females (Fisher 1983), are not pre-sent. Recently, however, a protocol for thedisinfection of M. rosenbergii eggs usingformaldehyde, hydrogen peroxide and amixture of antifungallantibiotic productshas ,been made available (Caceci et al.1997). It still remains to be experimentallydemonstrated whether these larvae are asviable as those from in vivo incubation. Ca-ceci et al. (1997) found that larvae from invitro hatching were morphologically indis-tinguishable from those hatched out natu-rally. The high larval survival rates ob-

served in this study are also an indicationof the viability of the larvae obtainedthrough in vitro incubation.

Acknowledgments

This work was supported by The Brazil-ian Council for Science and Technology(CNPq) through a doctoral grant to R. Cav-alli (Proc. 200796/96-8). Thanks are due toMr. Nopadol Phuwapanish, Department ofFisheries, Thailand, for providing theprawns, and to Mathieu Wille and Alexan-der Van Halteren for their technical assis-

tance. We are also grateful to Dr. WilliamDaniels, Delaware State University, USA,and Dr. Rocio Robles, University of Cadiz,Spain, and an anonymous reviewer for theirvaluable comments and suggestions.

Literature Cited

Ang, K. J. and Y. K. Law. 1991. Fecundity changesin Macrobrachium rosenbergii (de Man) duringegg incubation. Aquaculture and Fisheries Man-agement 22: 1-6.

Balasundaram, C and T. J. Pandian. 1981. In vitroculture of Macrobrachium eggs. Hydrobiologia77:203-208.

Brock, J. A. 1993. A synopsis of pathology, diseases,and production problems of cultured Macrobrach-ium, with an emphasis on experiences in Hawaiianprawn farming. Pages 361-391 in J. P. McVey,editor. CRC handbook of mariculture, volume I.CRC Press, Inc., Boca Raton, Florida, USA.

Caceci, T., C. B. Carlson, T. E. Toth, and S. A.Smith. 1997. In vitro embryogenesis of Macro-brachium rosenbergii larvae following in vivo fer-tilization. Aquaculture 147:169-175.

Cavalli, R. 0., P. Lavens, and P. Sorgeloos. 1999.Performance of Macrobrachium rosenbergiibroodstock fed diets with different fatty acid com-position. Aquaculture 179:387-402.

Cavalli, R. 0., G. Menschaert, P. Lavens, and P.Sorgeloos. 2000. Maturation performance, off-spring quality and lipid composition of Macro-brachium rosenbergii females fed increasing lev-els of dietary phospholipids. Aquaculture Inter-national 8:41-58.

Chang, C. F. and T. W. Shih. 1995. Reproductivecycle of ovarian development and vitellogeninprofiles in the fres~water prawn, Macrobrachiumrosenbergii. Invertebrate Reproduction and De-velopment 27: 11-20.

Chavez Justo, C., K. Aida, and I. Hanyu. 1991. Ef-fects of photoperiod and temperature on moulting,

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,..REPRODUCTIVE PERFORMANCE OF MACROBRACHIUM 67

reproduction and growth of the freshwater prawnMacrobrachium rosenbergii. Nippon Suisan Gak-kaishi 57:209-217.

Chow, S. 1982. Artificial insemination using pre-served spermatophores in the pa1aemonid shrimpMacrobrachium rosenbergii. Bulletin of the Jap-anese Society of Scientific Fisheries 48:9-11.

Corey, S. and D. M. Reid. 1991. Comparative fecun-dity of decapod crustaceans. I. The fecundity ofthirty-three species of nine families of carideanshrimp. Crustaceana 60:270-294.

Costa, H. H. and T. B. Wanninayake. 1986. Food,feeding and fecundity of the giant freshwaterprawn Macrobrachium rosenbergii from naturalhabitats in Sri Lanka. Pages 555-558 in J. L. Ma-clean, L. B. Dizon, and L. V. Hosillos, editors. TheFirst Asian Fisheries Forum. Asian Fisheries So-ciety, Manila, Philippines.

Damrongphol, P., N. E3!1gchuan, and B. Poolsan-guano 1991. Spawning cycle and oocyte matura-tion in laboratory-maintained giant freshwaterprawns (Macrobrachium rosenbergii). Aquacul-ture 95:347-357.

Daniels, W. H. 1993. Classification of male morpho-types of the freshwater prawn Macrobrachium ro-

senbergii based upon external morphology and re-productive condition and description of factors in-fluencing metamorphosis. Doctoral thesis. Missis-sippi State University, Mississippi, USA.

Daniels, W. H., L. R. D' Abramo, and L. D. Parsev-

a!. 1992. Design and management of a closed, re-circulating "clearwater" hatchery system forfreshwater prawns, Macrobrachium rosenbergiide Man, 1879. Journal of Shellfish Research 11:65-73.

Das, N. N., C. R. Saad, K. J. Ang, A. T. Law, andS. A. Hannin. 1996. Diet formulation for Macro-

brachium rosenbergii (de Man) broodstock basedon essential amino acid profile of its eggs. Aqua-culture Research 27:543-555.

De Caluwe, J., A. M. E. Korkor, D. Hisbi, P. Lav-ens, and P. Sorgeloos. 1995. In vitro hatching ofMacrobrachium rosenbergii eggs: optiinisation ofenvironmental parameters. Pages 83-86 in P. Lav-ens, E. Jaspers;--and I. Roelants, editors. Larvi '95Fish & Shellfish Larvicu1ture Symposium. Euro-pean Aquaculture Society Special Publication No.24, Belgium.

FAO. 1999. Aquaculture Production Statistics 1988-1997. FAO Fisheries Circular, No. 815, Revision11. Rome, Italy.

Fisher, W. S. 1983. Eggs of Palaemon macrodactylus.II. Association with aquatic bacteria. BiologicalBulletin 164:201-213. "

Graziani, C. A., K. S. Chung, and M. D. Donato.1993. Comportamiento reproductivo y fertilidadde Macrobrachium carcinus (Decapoda: Palae-

monidae) en Venezuela. Revista de Biologia Trop-ical 41:657-665.

Holthuis, S. A. 1980. FAO species catalogue, volume1. Shrimp and prawns of the world. FAO FisheriesSynopsis No. 125. United Nations Food and Ag-ricultural Organization, Rome, Italy.

Kuris, A., M. Ra'anan, A. Sagi, and D. Cohen. 1987.Morphotypic differentiation of male Malaysian gi-ant prawns, Macrobrachium rosenbergii. Journalof Crustacean Biology 7:219-237.

Ling, S. W. 1969. The general biology and develop-ment of Macrobrachium rosenbergii. FAO Fish-eries Report 3:589-606.

Malecha, S. 1983. Commercial seed production of thefreshwater prawn, Macrobrachium rosenbergii, inHawaii. Pages 205-230 in J. P. McVey, editor.CRC handbook of mariculture, volume I. CRCPress, Inc., Boca Raton, Florida, USA.

Mathavan, S. and S. Murugadass. 1988. An im-proved design for in vitro hatching of Macro-brachium eggs. Asian Fisheries Science 1:197-201.

New, M. B. 1995. Status of freshwater prawn farming:a review. Aquaculture Research 26: 1-54.

New, M. B. and S. Singholka. 1982. Freshwaterprawn farming: a manual for the culture of Ma-crobrachium rosenbergii. FAO Fisheries Techni-cal Paper, No. 225. FAO, Rome, Italy.

O'Donovan, P., M. Abraham, and D. Cohen. 1984.The ovarian cycle during the intermolt in oviger-ous Macrobrachium rosenbergii. Aquaculture 36:347-358.

Pandian, T. J. and C. Balasundaram. 1982. Moult-ing and spawning cycles in Macrobrachium no-bilii (Henderson and Mathai). International Jour-nal of Invertebrate Reproduction 5:21-30.

Patra, R. W. R. 1976. The fecundity of Macrobrach-ium rosenbergii. Bangladesh Journal of Zoology4:63-72.

Ra'anan, Z., G. Issar, A. Freri, and R. Rodrigues.1990. Effect of winter on growth of the prawnMacrobrachium rosenbergii in a commercial farmin the tropics. The Israeli Journal of Aquacul-ture-Bamidgeh 42:22-30.

Rao, K. J. 1991. Reproductive biology of the giantfreshwater prawn Macrobrachium rosenbergii (deMan) from Lake Kolleru (Andhra Pradesh). IndianJournal of Animal Sciences 61:780-787.

Villegas, C. T., A. Trino, and R. Travina. 1986.Spawner size and the biological components ofthe reproduction process in Penaeus monodl;n Fa-bricius. Pages 701-702 in J. L Ma~ean, L. B.Dizon, and L. V. Hosillos, editors. The First AsianFisheries Forum. Asian Fisheries Society, Manila,Philippines.

Wickins, J. F. and T. W. Beard. 1974.Observationson the breeding and growth of the giant freshwaterprawn Macrobrachium rosenbergii (de Man) inthe laboratory. Aquaculture 3: 159-174.