618 EPIZOIC SCCTORIAN OF COPEPOIJA

reasons why such a placement does not seem advisable. This organism possesses certain characteristics not described in the previous literature: most notably, the Parkville strain possesses an acute curvature of the dorsal border. not present in other species. -41~0. the pigmentation of the American and Stein strains of B . steini was darker than that of the Parkville strain. and the macronucleus of the Penard strain was too elongated. In addition. the A Z l I of the Parkville strain travels in a straight line towards the gullet, whereas Kahl described the AZJI of B . stcini as turn- ing sharply towards the right. Another reason for not including the Parkville strain in B . steini is pos- sible homonomy within the species. For example. the “schon rot” strain included in B. steini has a size range of 150-200 p ; another. the “hellrot” strain is only 70-80 ,u.

In recent years. Blcphaviswm taxonomy has been qreatly hindered by the lumping of many obviously different morphological types into one species. B. undulans. Even though Suzuki ( 7 ) divided the species into three subspecies. and Bhandary( 1 ) later elevated the three subspecies to specific level and named three additional species. many workers still claim to be working with “B. undulans.” Therefore. in an attempt

to prevent B. steini from becoming the species for a21 compact forms. just as B. undulans has been the name for all blepharismas, no matter what their mor- phology. and bearing in mind that B. seculum does not coincide with any of the older species, we believe that it should be removed from its previous tentative placement in B . stcini(3) and given specific status of its own.

REFERENCES

I . Bhandary. A. V. 1962. Taxonomy of the genus BZephu- r i s m with special reference to Blephurisina undulans. J . Protozool. 9, 135.42.

2 . Chunosoff, L. R. Hirshfield, H. I. 1964. .4 cytochemical investigation of the cysts of a species of Blephavisma. J . Pro- fosool . 11 (suppl.). 29-30.

3 . Hirshfield, H. I., Isquith, I. R. 8r Bhandary, A. \‘. 1965. .i proposed organization of the genus Blepharisma Perty and description of four new species. J . Protor;ool. 12, 136-41.

4. Kahl, .4. 1930-35. Wimpertiere odev Ciliuta (Iniusoria) G. Fischer, Jena.

5 . Rudzinska, M. 1955. The use of OsOI as a fixative for Feulpen-stained preparations. J . Biophjfs. Biochettz. CytoZ. 1, 472-6.

6. Stolte, H. A. 1924. Morphologische und physiologische Untersuchungen an Bkpharisnzn wzdulans Stein. Archiv. Pro- t i s tenk . 18. 246-301.

7 . Suzuki. S. 19S1, Taxonomic studies on Blepharisma Stein with special reierence to macronuclear variation. J . Sci. Hiroshima 1:. 15, 205-20.

J . PROTOZOOL. 1 2 ( 4 ) . 615-625 (19651

Palcacineta sp., an Epizoic Suctorian Found on Gulf of Maine Copepoda

KENNETH SHERMAN and EVERETT G. SCHANER

t7 . S. Birrenrr of Coiiziii~rcial FiJheries Biologird Luborntory, Boothbaj Harbor, illairze

SYSOPSIS. .in epizoic suctorian irom Guli oi Maine coastal waters. designated as Paracineto sp.. is described. Morphologi- cal measurements are given ior 2 3 small. medium. and large specimens. Mean length n’as 200 p and average cell body diameter 39 p . Oi 21 copepod species and 19 zooplankton groups examincd. only copepods oi the genus Metridiu showed any Paracineta attached. Suctorian occurrence was. with a single exception, limited to adult copepods. with the larger females showing the heaviest incidence. Differences in areal occurrence were observed with greatest incidence oi Parncinrta

URISG examination of Gulf of Maine coastal D zooplankton. large numbers of an epizoic marine suctorian belonging to the genus Paracineta were ob- served attached to the copepods Metridia lucens Boeck and Metridia longa (Lubbock). Previous observations of suctorians epizoic on several general of marine copepods have been reported from widely scattered areas (Table I ) . S o previous record of Paracineta on the genus Adetvidia has been reported from the western Atlantic. This report describes the suctorian and presents observations on host specificity among

on .\.I. / w e n s in the eastern and central Gulf, and lowest num- bers in the western area. This differential occurrence is ac- credited to an apparent cold water affinity of the suctorian. I t is suggested that Parorineta could ‘be carried into the Gulf durinc periodic intrusions of cool Nova Scotian water, reaching the western area in the south’westerly flowing Gulf of Maine eddy system. S o significant differences in vertical distribution \yere iound in Poruriiicta incidence on Metridiu among the depths sampled (0, 10, 30. and 60 m ) . No harmful effect of Pnraciizeta on Jletridia was evident.

zooplankters. host condition, distribution, and seasonal occurrence.

Paracineta sp. (Suctoria, Podophryidae) (Fig. 1)

The diagnosis given here is based on morphological measurements of 2 3 small, medium, and large speci- mens removed from five female 14. lucens (Table 2 ) . ,411 measurements were made of specimens fixed in 10% formalin and stored in 70% methyl alcohol.

Diagnostic characters of the genus Paracineta have

Eprzoic SUCTORIAN OF COPEPODA 619

Fig. 1. The suctorian epizoic Paracineta sp. (483X phase Fig. 2 . Incidence of Pavacineta attachment on Metridin contrast) BP, Basal plate ; LS, Lower-stalk; US, Upper-stalk ; Zzicens ; A) Slight-incidence, B) Moderate-incidence, and C ) SC, Supporting cup; CB, Cell body ; N, Nucleus ; T, Tentacles ; TK. Tentacle knobs.

Heavy-incidence.

620 EPIZOIC SUCTORIAN OF COPEPODA

TABLE 1. Pr.pt,ioi/s obse, catlotis of siictoriun cpi2oic.s on inariiie copepods.

Author Suctnrinii \p t ' c i t '< Cop?pod host Geographic location

Cmll(2)

Claus(4)

Lebour(8) Rose(l1)

Rose (12) Rose( 13) Schriider( 14)

JWPS( 7)

Schrb;der( 15) Schulz (16) Sewell( 17)

Steuer(l8)

Steuer(19)

Acinetidae

Ophryoden ~ 7 r o n t ri t i tierion Ephclota sp. Ephelota critstaceorit i n

Eplrelota gcni vi ipnra

Eplielota sp. Unknowii Toliopli y ra i n t eirzi pta

Tokophyra stezieii Scin6.a t itbwosa Aci irefa caclrirc t a p Paracincta gaetani Hallezia scottocaln,t i

Iliiknoivn

To7;ophyr.a c n t t l p l ? i i t l a

Paracini ta 111, itroitiani i t i i i c

Ephelota gcviitiipara Paraci neta ple t i roni a i t i mar

Tachidius discipes T. littoralis Zdya f itrcata Tisbe f itrcata Calnniis fitiiiiaiclt icirs " on the lrgs of a copepod ' ' Calancls f i n mnrch iczts Caiidacia arinnta Aermelkmal, Germany Pontplla ntcditerraiitw Bay of Algiers Disset a palttmbo Mediterranean Eitclineta and Sout,h Atlantic

Eitchaela hcbes Adriatic ' I o n the ahdoiiien of copepods ' ' Brackish water of the Bot,tsanclgebrit, Germany Eitclraetn zrolfeiLdeni Arabian Sea E . marina Gac.ta!iiis antarcticits G. cirrvicornis Scottocala>i tt.s dauglis l i i P l m r o trio ni ! t i t i .cipltius Benguela current P . abdoi~i inal is Plcztroinatti ma bowalis Benguela current P . gracilis P . gracilis P. Bormlis

Vicinity of Boulannais, France

Vicinity of Messina, I ta ly Clj-de Sea area Vicinity of Plymouth, England Vicinity of Roscoff, France

, l idr idin sp.

been given by Collin(5) and include the following: monaxial symmetry, with tentacles radiating from the body and never fasiculated; style long and thin with striated bundles reduced or absent: and repro- duction by exogenous budding.

Diagnosis. Total length, measured from the upper pole of thr cell body to the margin of the basal plate, ranged from 131 to 262 ,u with a mean of 2 0 0 ,u. The cell body varied from spheroid to pear shape ranging in diameter from 23 to 66 p with a mean of 39 ,u, A single rounded nucleus, with a mean diameter of 11 p was present in each of the 23 speci- mens. In a medium of lactic acid and methyl blue, coarse granules and reiractile particles could be dfitinguished in the protoplasm. A spherical contractile vacuole measuring 7 ,u in diameter and located at the cell body periphery was observed in one specimen. The cell body is supported by an elongated flexible upper-stalk, which thickens into a supporting cup at the distal end, and a shorter rigid lower-stalk modified into a basal plate at the proximal end, which adheres to the host. The lower-stalk is approximately one-third the length of the upper-stalk. In all specimens examined, the greatest number

TABLE 2. Xorphological ii1msiirenients of Paracineta sp .

Range (,L) Mean (,L)

Total length Cpper.stalk length Broad aspect of siipportiiig 1,owrr-stalk length 1,nwrr-stnlk diameter Basal plate diameter Cell body diamrtrr Sucleus dilunet er \'.icuolt. r i i n m r t r r

cup

131-262 200 47-155 106

9- 28 16 23- 52 38

5- 9 6 9- 23 15

43- 66 39 7- 1 4 11

7

of tentacles were located on the upper half of the cell body. \Yhen extended they were equal or greater in length than the cell body diameter (Fig. 1).

Remarks. The present species resembles Paracineta guetuni Sewell (Fig. 3A) and Paracineta fleuromam- ittae Steuer (Fig. 3B). In P. gaetani the flexible upper- stalk is thicker and shorter, with a mean length 7 3 8 p in P. gaetani Sewell( 17), as compared to 106 p in Paraineta sp. The upper-stalk in P. pleuromammae is greatly thickened, providing a cup-like support which covers nearly one-half of the cell body. In Puracineta sp. the supporting cup is greatly reduced covering approximately one-fourth of the cell body surface. Structure of the tentacles is wider than in Pararineta sp., with the distal knob less distinctly formed( 19). Information regarding specimen preser- vation of P. gaetani and P. pleuromammae was not available in the literature. However, the ratios of various body parts, particularly the upper and lower stalks, and the basic structure of the cell body sup- porting cup would not be expected to undergo radical change with preservation.

METHODS

Examination for the presence of Pavacineta was made on copepod species and other zooplankton groups from 120 samples collected from Gulf of Maine coastal waters during spring, summer, fall (1963), and winter (1964). Station loca- tions, dates of sampling, and locations of Pavacineta occurrence are given in Fig. 4. Two types of zooplankton sampling de-

EPIZOIC SUCTORIAN OF COPEPODA 621

vices were used: a high-speed Gulf 111 sampler, and Clarke- topography permitted, simultaneous 15-min hauls at 0, 10, 30, Bumpus (CB) closing-nets, The Gulf I11 sampler was towed and 60 m were made. All tows were taken during daylight at approximately six knots for 30 min in a step-oblique hours. Numbers of zooplankters per 100 m3 of water strained manner, with 10 min each a t the surface, 10, and 20 m. This were determined for samples collected during Rorqual spring gear was used on the spring and summer cruises of the R. V . and summer cruises. Numbers per 10 ms of water strained Rorqud. Clarke-Bumpus samplers were used on the surveys were calculated for collections made during Rovqzial fall and conducted during the fall and winter. When depth and bottom winter cruises.

Textfii.

Fig. 3.

A

D

Ten-no. 8.--Paradneta gufani sp. nov. A-E, Different individusls from the same host, Gulanw anfarcficus Wolfend.

1 8 8 . 4 .

The suctorians, A) Paracineta gaetani, from Sewell, Paracineta pkuromammae STLIUER 1928. b, c Knorpung. d an P. racilis (CIS.), 9 von Station 85. v.

B) Pavaciizeta pleuronmrzmae, from Steuer.

A

7 0 0 m.

62 2 EPIZOIC SUCTORIAN OF COPEPODA

TABLE 3. Copepod spcrirs ntid itiajor zooplankton groups rsamitwd f o r Pzracincta incidenrr .

Major zooplaiiktoii Copepod slireies groups

RESULTS ASD DISCUSSIOS

Zooplankton Specificity

Of the 2 1 copepod species and 19 other zooplankton groups found in our samples, only -51. k e n s and M . longa showed any evidence of Paracineta attachment, indicating a high degree of host specificity among Gulf of Maine coastal zooplankters. Copepod species and major zooplankton groups examined for Para- cineta incidence are listed in Table 3 . Paracineta were found only during fall and winter (Table 4) .

Three categories of Paracineta incidence on J f e - tridia. based on estimated numbers of suctorians pres- ent per copepod, were recognized: slight ( 1-50), mod- erate (ca. 50-100). and heavy (ca. 100-250). In cases of slight incidence, suctorians were found on the furca, urosomal segments. and occasionally on the posterior margin of the fourth metasomal segment (Fig. 2A). The attachment area extended anteriorly from the caudal furca to the second metasomal segment re- gion in cases of moderate incidence (Fig. 2B), and over the entire dorsal surface. sides of the metasome, and around the furca in cases of heavy incidence (Fig. 2C).

Examination for possible copepod size-selectivity by Paracineta was made by obtaining length-frequency measurements (from anterior cephalosome to caudal furca posterior margin) of all affected and non-affected M . lucens taken from the winter sample with highest suctorian incidence. Lengths ranged from 1.09 mm to 3.22 mm; with males ranging from 1.85 mm to 2.13 mm. and females from 2.54 mm to 3.22 mm. Immature forms measured less than 1.85 mm, with the exception of several stage V M . k e n s less than 2.54 mm, which could be identified as developing females. Paracineta were found only on adult M . lucens. All other M . lucens and M . longa in our samples were examined, with no evidence of Paracineta incidence on immature copepods except for a single developing male measuring 1.76 mm in length. General absence of affected immature M . lucens implies that either Paracineta is lost through molting, or that the suctorian favors adult forms as a substrate.

Suctorian-incidence by sex among adult M . lucens was determined for all samples. A differential occur- rence was found between males and females, with 96% of males showing slight incidence and 4% with mod- erate incidence. Among females 7570 showed slight, 1 5 3 moderate, and 10% heavy incidence of Para- cineta. Of 12 female M . longa affected, 1 1 showed slight and one moderate incidence. Affected females outnumbered males in our samples a t a 3:l ratio. Dominant metridian forms in all of our samples were adult females and immature specimens. The higher suctorian incidence among females is accredited to their great numbers and large size, which would appear to favor them over the smaller males as a suitable substrate.

Distribution

Sumbers of affected and non-affected M . lucens found during winter were compared by coastal area- western, central, and eastern (Table 5). A X' value of 12.23 (2 df, P<.Ol), indicated that differences found among areas were significant, with greatest occurrence in the eastern ( 1 7 % ) and central (16%) areas, and lowest in the western region (12%). The only other Paracineta occurrence was a t a single station (where 106 affected M . lucens occurred) located on the easternmost transect during fall (Fig. 4 ) .

Salinity and temperature values were plotted with

T.\BI.E 1. Tofu1 ti i / tnbr,rs of ufccfrd c r i i r l no t r -n f fwfe t l 11. lueeiis ant7 M. loriga f o r cnch of the seusotiul rriiiars.

Spring Summer Fall Winter Ili. l l i C C t t H X. l i r c w s v. zltcrtls 31. lzrccns M . longa ro./1no,. So./li:)Om3 So./10m3 No./lOnis No./lOms

Xoll-:lffc.cted. 5,592 12,344 13,159 2.88; 140 A f f w t e d - - 106 487 12

EPIZOIC SUCTORIAN OF COPEPODA 623

' r m m 5. Siirriberi of a f r c t t d and non-affected Metridia lu- cens by coastal urea, winter, 1964.

(- M . lzicens -, Affected Kon-affected Total Percent

Aie:t No.'s/lOnl? Ko.'s/l@n? ~o.'s/lOius affceted

F h t 146 'ill 857 17.04 Cell tral 146 779 925 15.i8 Wrht 195 139i 1592 32.35

total numbers of affected and non-affected M . lucens to determine the possible relation of these variables on Paracineta distribution (Figs. 5A and B) . Greatest occurrence of suctorian concentration paralleled the abundance of &I. lucens in high salinity water ( > 3 2 .SO "J,,,,). However, incidence of affected M . lucens was reduced from 51-100/10 m3 to less than 25/10 m3 in water warmer than 4.loC (Fig. 5A). Im- migrant cold-water zooplankters, found in periodic intrusions of Nova Scotia water, have been reported

from the eastern Gulf of Maine( 1). I t is possible that areal differences in suctorian incidence could be related to periodic cold-water intrusions, with fewer numbers reaching the western Gulf during their plank- tonic free-living embryonic period in the southwesterly flowing Gulf of Maine eddy system. Absence of Paracineta during warmer months (May to July), low numbers found in fall, and high numbers in winter suggest that this suctorian is associated with cool waters.

Metridia lucens is known to undertake day-night vertical migration with maximum numbers occurring in deep water during daylight hours, and at the surface at night(3,lO). The incidence of affected and non- affected M . k e n s between and among depths was compared for samples collected during winter (Table 6 ) . No significant differences in X' values were found between depths. A X2 value of 0.92 ( 3 df) demon- strated that no significant differences among depths

I

.I

t, W E S T E R N A R E A I I I 5

50

40

STERN AREA

I Paracineto sp. Occurrence ( PI I I 1 I I

RORQUAL CRUISE 4 MAY 2 5 - J U N E 2 , 1 9 6 3 RORQUAL CRUISE 5 JULY 10 - 2 2 , 1963 0 R O R Q U A L CRUISE 8 OCT 26- NOV 12, 1963 A RORQUAL CRUISE 2 JAN.21-FEB 14, 1964 0

I I I 1 I 1 1 1 I I I 1 I I 1 1 1 I I l l 1 1 I+

71. 50' 4 0 3 0 20 10' 70 . 50 40 ' 30' 10' 10' 6 9 . 50' 40' 30' 90' 10' 6 8 . 50' 4 0 ' 30' 20 10' 6 7 ' SO' 40'

L30

- 20

-10 '

- - 4 d

- 10

- 4 0

- - 3 0

- 2 0

- 10'

--43

- 50

- 4 0

--30

20 '

10'

4 2

~ ~

Fig. 4. Station locations and periods of zooplankton collections made during spring, summer, fall (1963) , and winter (1964).

624 EPIZOIC SUCTORIAZ: OF COPEPODA

5

4

v 0 Y

I 3 c

i3 Y a z Y I-

2

1

5

4

U 0

Y I 3 c

a Y a

( 3

z YI c

2

1

r -A' L

~ M e t r i d i o lucens 1 a f f e c t e d 1 I-.-l

- c . I . N U M B E R S 1 0 ~ 3 I

1 1 - 20 21- 5 0 i 1 - 1 ° 51- 100

ij

I I I 1 2 9 30 3 1 32 33

S A L I N I T Y ?Lo

B

M e t r i d i o lucenr non -a f fec ted

8 N U M B E R S / l o m J I

11-15 1 6 - 5 0

101- 500 ' i 51 - l o o

I -501- 1000

I I I 1 29 30 31 32 33

S A 1 I N I T Y %, Fig. 5 . Comparison o i salinity, temperature, and total num-

bers oi Ketridia lztcens; A. Affected M . Zzrcens, B. Non-affected .II. lucens. Circle diameter size represents numbez of M . lucens per lorn3 of water strained.

EPIZOIC SUCTORIAN OF COPEPODA 625

T\BLE 6. ?\’umbers of afferted and non-affected Metridia lu- ceiw by depth, winter, 1964.

~~ ~ ~ ~

(- M , lucens ~-------, (u1rtcrs J -Uo.’s/10m3 No.’s/lOms No.’s/lOm*

UCptll Affected Son-xff ected Total

0 10 30 60

11 5ci

188

74 332

1169

85 388

1357 232 1312 1544

occurred within the range sampled (0-60 m), suggest- ing that the 0-20 m oblique samples collected during Rorqual spring and summer cruises provided adequate collections for seasonal comparison of Paracineta in- cidence. No loss of attached Paracineta by abrasion or turbulence was observed in several samples avail- able for examination, which mere collected with the high speed Gulf I11 sampler during winter, 1964.

Condition of Host

Suctorian epizoons use the host species as a sub- strate. adhering by means of a cementing substance secreted by the free-living embryo on contact with the host ( 5 ) . They are predaceous on smaller protozoans, generally using an array of tentacles located on the outer surface of the cell-body for capturing and in- gesting prey( 6 ) . No penetration into the body tissues of either M . lucens or M . longa was observed. A dis- tinct basal-plate attached to the outer cuticle of the copepod host was found supporting all of the suctori- ans (Fig. 1 ) . No apparent harmful effect was evident on visual comparison of affected and non-affected M . Zucens of the same sex and length. I t was not feasible to assess host condition by morphometric methods, since greatest growth of most crustaceans is known to occur only during a brief period in the intermolt cycle (9) . Affected Metridia specimens, with one exception, were adult forms. Laboratory observations of Me- tridia behavior, particularly swimming efficiency,

would provide more definitive information regarding possible effects of Paracineta attachment.

REFERENCES

1. Bigelow, H. B. 1926. Plankton of the offshore waters of the Gulf of Maine. Bull. U. S. Bur. Fish. 40, 1-509.

2. Canu, E. 1892. Les Cop6podes du Boulonnais. Trao. Lab. 2001. Mar. Wimereux. 6 , 1-292.

3. Clarke, G. L. 1933. Diurnal migration of plankton in the Gulf of Maine and its correlation with changes in sub- marine irradiation. B i d . Bull. 65, 402-36.

4. Claus, C. 1863. Die freilebenden Copepapoden nrit be- sonderer berucksichtigung der fauna Deutschlands, der Nordsee und Mittlemeeres. Leipzig.

5. Collin, B. 1912. Etude monographique sur les .4cinetikns. Arch. 2001. Exptl. G i n . 51, 1-457.

6. Hyman, L. H. 1940. T h e Invertebrates. McGraw-Hill Book Co., New York, vol. I.

7. Jems, M. W. 1937. On the Drotozoan Darasites of - _ _ . Calanus jnmarchicus in the Clyde Sea area. Quart. I. Mi- croscop. Sci. 79, 589-658.

8. Lebour, M. V. 1917. The microdankton of Plvmouth Sound. J . Mar. B i d . Assoc. U. K . 11, i33-82.

9. Passano, L. M. 1960. Molting and its control. In: T h e Physiology of Crustacea, edited by T. H. Waterman. Academic Press, New York, VoI. 1.

10. Raymont, J . E. G. 1963. Plankton and productivity in the oceans. Pergamon Press, New York.

11. Rose, M. 1924. Notes faunistiques sur les Copkpodes pelagiques des cot& de France. Bdl . SOC. Zool. Fr. 49, 328-32.

12 . Rose, M. 1926. Les plankton de la Baie d’Alger pedant les mois d’Octobre et de Novembre. Btdl. SOL. Hist. Nat . Afrique d u Nord. 16, 304-8.

13. Rose, M. 1929. Copkpodes p6lagiques particulierement de surface provenant des Campagnes Scientifiques du Prince Albert ler de Monaco. Result. Camp. Sci. Monaco 78, 1-126.

14. Schroder, 0. 1907. Die Infusorien Deutschen Siidpolar- Expedition 1901-1903. 9 Zoologie 15, 350-60.

15. Schroder, 0. 1911. Eine neue marine suctorie. Sit,-. Akad. Wiss. Wien, Math.-Nut. K1. 120, 757-63.

16. Schulz, E. 1932. Beitrage zur kenntnis mariner Suc- torien. Zool . A m . 97, 289-92.

17. Sewell, R . B. S. 1951. The epibionts and parasites of the planktonic Copepoda of the Arabian Sea. Scientific Re- ports of the J o h n Murray Expedition 9, 255-394.

18. Steuer, A. 1928. Uber eine neue Paracineta aus dem Siidatlantik. Sitzb. Akad. Wiss. Wien, Math.-Natw. Kl. 137, 296-301.

19. Steuer, A. 1932. Copepoda part 6: Pleuromamma Gies- brecht 1898, der Deutschen tiefsee Expedition Wiss. Ergebn. Valdivia 24, 1-119.