Two ew a d hree redescribed species of Viscosia (Nema oda, O cholai idae) N. S

ol & J . Shar a

Mari e Biolog Belgi

Sec io , Zoolog

Ke words : Ne a odes, freelivi g,

I s i

e, S a e U iversi

ari e, brackish, axo o

of Ge

, Ledega cks raa 35, B-9000 Ge

,

, ew species, Viscosia

Abs rac a si sp . ov . a d Viscosia he erolai a sp . ov. are described fro Lake Greveli ge a d Scheld (The Ne herla ds) . Viscosia glabra (Bas ia , 1865) de Ma 1890, Viscosia fra zii Bo cher d Viscosia viscosa (Bas ia 1865) de Ma 1890 are redescribed, aki g i o acco ew i por a ers . J ve ile speci e s are depic ed for V. viscosa . Viscosia car le e sis Di levse , 1921 is s o h Viscosia glabra (Bas ia , 1865) . Mo o cholai s viscos s Allgb , 1930 a d Mo o cholai s elega s se s Sch r a s-S ekhove , 1942, 1950 ( ec . Kreis, 1924) are s o ized wi h Viscosia viscosa (Bas ia , 1865) . Viscosia coo

Eas er 1977, a charac ized wi

I

rod c io

The ide ifica io of a Viscosia-species is a diffic l a d he e a ive i for a io wi hi he descrip io recorded o l o ce i he li era re, a d of e o l i for a io o variabili is lacki g. Five Viscosia-species fro differe habi a s are co We ried o i prove he descrip io s aki g i o acco b S ol (i prep .) .

Ma erials a d

ask d e o he e or o s ber of species described s . Moreover, abo 70% of he k ow species are o e or few speci e s were fo d, i dica i g ha pared a d heir si ilari ies a d differe ces disc ssed . he i por a a d ew charac eris ics poi ed o

e hods

Locali ies Dieve ga : A pol hali e brackish wa er pool i

he so her par of he a re reserve `He Zwi ', si a ed i he ex re e or h-wes er cor er of Belgi . A ore de ailed descrip io is give b S ol e al (1981) . Sedi e : well sor ed fi e sa d derl i g a 2-3 la er of de ri s . Coordi a es : 51‚21'00"N, 03 22'30"E . Sali i 8-40%0 . Sa pled : Oc ober 1973-Sep e ber 1977 . Eas er Scheld : 51 32'40"N, 03 59'50"E . Fi e sa d sedi e . Sa pled : J e 1979-Ma 1980 . Lake Gre eli ge : 51 46'00'N, 03 56'00"E. Fi e edi sa d . Sa pled : J e 1979-Ma 1980 . Hydrobiologia 114, 123-147 (1984) . © Dr W . Junk Publishers, The Hague . Pri ted i the Netherla ds.

1 24

Tech iq es

All sa ples ere fi ed i 4% for aldeh de a 70 C . The e a odes ere ra sferred o deh dra ed ed o Cobb-slides for ide ifica io . gl cerol (Sei hors , 1959 ; De Grisse, 1965) a d . o i gs ere ade i h he aid of a ca era l cida o a Lei Dial 20 EB a d a Wild M20 The dra icroscope . All eas re e s, e cep ra ios, are i icro e ers . The al es i he eas re e for la i dica e: cephalic se ae

er e ri g

e ral pore

phar

l a/ M

a

s/ cloacal aper

re

o al le g h

correspo di g bod dia e er (c .b .d .) The b ccal i de for ca i :

la, e plai ed i

he abbre ia io s, is sed o describe he

orpholog of he b ccal

br ( BI = B odified af er Belog ro & Belog ro a, 1977) LV D RV Spic la are eas red alo g he arc . We se he er s ` e ral' pore a d ` e ral' gla d as he e cre or f c io of hese s r c res has o bee pro e . O her er i olog is adap ed fro Coo a s (1978) . The dis i c io be ee papillae a d se ae is ade as follo s : 2, = papillae; > 2 = se ae . O e ale a d o e fe ale of each species described i his paper are deposi ed i he collec io of he I s i oor Dierk de, Rijks i ersi ei , Ge , Belgi .

Abbre ia io s a b br c c' a.b .d . c .b .d . s .d . B BI D L LV M RV S V

bod le g h/ a . bod dia e er bod le g h/ phar geal le g h le g h basorabdio / le g h b ccal ca i (%) bod le g h/ ail le g h ail le g h/ a al bod dia e er a al bod dia e er correspo di g bod dia e er ber of speci e s e a i ed s a dard de ia io ari h e ic ea le g h/ id h of b ccal ca i b ccali de le g h dorsal oo h/ le g h b ccal ca i (%) bod le g h (i icro e er) le g h lef e ros bla eral oo h/le g h b ccal ca i (%) iddle of bod le g h righ e ros bla eral oo h/le g h b ccal ca i (%) spic le le g h (i icro e er) posi io of l a fro a erior as a perce age of he o al bod le g h

1 25 Descrip io s Viscosia glabra (Bas ia , 1865) de Ma , 1890 s . o . : Viscosia car le e sis Di le se , 1921

(Fig. 1 & Pla e 1)

Locali : Lake Gre eli ge , The Ne herla ds Meas re e s

as ( s .d .

R L a b c c' V l a Spic les

al

2035 95 .3 51 .3 f 5 .2 6 .1 f 0 .2 9 .8 0 .6 10 .0 0 .5

182

15

34

211

336

-

1851

38 b=6 .1

39

38

19

c = 10 .1

206

325

-

16

38

38

38

39

22

1675 1890

b = 5 .8

c = 8 .8

7

176

210

347

1186

2018

18

43

50

52

60

29

2234 (slide No . 502) b = 6 .4

c=10 .3

V=53 .1

8

181

209

328

1040

1839

12

46

48

49

53

25

2076 a = 39 .2

BIa

(1900-2234) (37 .2-48 .7) (5 .5-6 .4) (8 .4-10 .3) (7 .3-9 .5) (50-53)

(24-30)

171

a = 37 .2

92

2069 ± 151 .2 38 .5 ± 6 .6 6 .0 ± 0 .4 9 .0 ± 0 .8 8 .9 ± 0 .9 51 .2 ± 1 .3

6

a = 48 .5

91

99 ( = 5) ra ge

2055 (slide No . 501) a=52 .7

62

s .d .

(1890-2151) (46 .8-59 .2) (5 .8-6 .2) (8 .8-10 .3) (9 .5-10 .7)

26 .4 ± 2 .3 6

= 5) ra ge

b = 6 .8

c=8 .8

V=56 .6

1 .8 ; 44% 74%74%96%

BIg

2 .1 ; 44% 74%74%97%

Descrip io Males : lo g, sle der appeara ce

i h lo g hi ail. C icle i ho or a e a io . Head aperi g o ards a erior e d . Lips i h o e circle of 6 circle of 6 e er al labial papillae + 4 cephalic papillae .

i

e i er al labial papillae a d a seco d

1 26

I

I

I

Fig. 1 . Viscosia glabra (Bas ia , 1865) A . Head e d 31 ; B . Head e d Y2; C . Phar geal regio G . Spic lar appara s 6 1 ; H . Sper cells (51 .

61 ; D .

To al ie

a,; E . Spic

lar appara

s 62 ; F. Tail shape, ca dal gla ds

a,;

1 27

Pla e 1 . Viscosia glabra (Bas ia , 1865)

a,;

1 . A phid (la eral ie ) 61 ; 2 . Dorsal oo h (la eral ie ) 3 . Lef e ros bla eral oo h (la eral ie ) 6 1 ; 4. Spic le 5 . Media peria al papillae (prea al) $Z ; 6 . Media peria al papillae (pos a al) $Z ; 7 . To al Vie 62; 8 . Tail $Z .

i h`forked' ip (51 ;

1 28 A phids i h c p-shaped fo B ccal ca i 18 µ lo g, 8 µ ide (ra ge : 17-21 X 8-10 µ ) . Righ e ros bla eral oo h pro i e , reachi g al os o ip of b ccal ca i . Lef e ros bla eral a d dorsal oo h s aller. Phar sligh l broade ed o ards base . Phar geal al e dis i c , loca ed 7 µ belo b ccal ca i . Cardia dis i c , sc lar, 11 µ lo g . Ner e ri g a 54% of phar geal le g h . Ve ral pore abo 40µ behi d er e ri g; a p lla dis i c ; e ral cell loca ed o righ side of i es i e, abo 136 µ fro he base of he phar . Reprod c i e s s e i h o opposed o s re ched es es o righ side of he i es i e; sper spherical, 7 µ i dia e er; spic les paired, i h `forked' ip, 30 µ lo g; fai peria al alae prese , i h 4 pairs of i e papillae a d 2 edia se ifor papillae . Vas defere s separa ed fro he sc lar ejac la or d c b a sphi c er a he le el of he os a erior ca dal gla d cell . Three ca dal gla ds i h prea al cell bodies 132, 176 a d 294 µ respec i el fro cloaca; he firs a d hird o righ side a d he seco d o lef side of he i es i e . Tail arro i g i pos cloacal regio a d c li drical hro gho i s le g h ; 204 µ or 10 .7 X a .b .d . lo g. Fe ales: si ilar o ale e cep i he follo i g: A phid 7µ ide, 39% of c .b .d . B ccal ca i 19 X 11 µ (ra ge : 19-21 X 9-11 µ ) . Reprod c e s s e i h o eq all de eloped bra ches ; bo h o aries a idro o sl refle ed, loca ed o righ side of i es i e ; eggs 62-77 X 29-33 µ . De a ia s s e `si ple' co sis i g of a o arial sac a d a os osi . Tail 8 .9 X a.b .d ., b si ilar i appeara ce o ha of ales . Disc ssio V. glabra de Ma , 1890 is he oldes described species of Viscosia charac eri ed b papillae as a erior se se orga s a d a filifor ail . I is ci ed abo 60 i es i he li era re fro all o er he orld . La er o , closel rela ed species ere disco ered : V. car le e sis (Di le se 1921), V. eridio alis Kreis 1932, V. da Kreis 1932, V. pse doglabra Kreis 1932, V. acra phida Chi ood 1951, V poseido ica Belog ro & Belog ro a 1977 a d V sp . Gerlach, 1957 . E cep for V. car le e sis hich as freq e l e io ed, a d V. acra phida, os of he descrip io s of he o her species ere based o o l a fe speci e s . The si ilari ies a d differe ia i g da a of hese species are s ari ed b S ol (Table 2 ; i prep .) . I 1921 Di le se described a e species, V. car le e sis, closel rela ed o V. glabra, b differi g fro i ai l b a higher a-ra io (63 .5 agai s 40-45) . As ore species ere fo d, his charac er beca e seless (see Table 2, S ol i prep.) a d e co sider V car le e sis as a s o of V glabra (s gges io alread ade b Allge , 1959) . The rela io ship be ee V glabra a d V. acra phida has bee poi ed o b Wieser & Hopper (1967) a d b S ol (i prep .) . We refrai fro f r her disc ssio abo he differe ia i g charac ers of he o her species of he gro p il ore acc ra e descrip io a d i for a io o ariabili beco e a ailable .

1 29 Viscosia fra

ii Bo cher, 1977

(Fig . 2 & Pla es 2, 6)

Locali : Lake Gre eli ge , Eas er Scheld , Wes er Scheld i fi e o Meas re e s

as ( s .d . L a b c c' V l a Spic les

61

2222 .5 46 .6 5 .7 16 .3 4 .6

± 190 .2 ± 5 .1 ± 0 .3 ± 1 .4 ± 0 .2

29 .3 ±

261

420

-

21

45

45

50

56

± 213 .7 ± 8 .5 ± 0 .4 ± 0 .9 ± 0 .3 ± 1 .9

(1978-2497) (29 .1-52 .0) (5 .1-6 .2) (15 .8-18 .0) (4 .3-5 .2) (50-54)

2292 2427 (slide No . 503)

b=5 .8

c = 18 .0

9

222

266

376

-

19

41

42

48

53

31

2065 2200

b = 5 .9

c = 16 .3

8

202

248

405

1266

2358

21

39

40

41

48

28

2497 (slide No . 504) a=52 .0

92

2352 .4 42 .6 5 .8 16 .7 4 .9 52 .6

ra ge

(28-32)

212

a = 41 .5

91

99 ( = 5)

(2000-2476) (41 .5-54 .1) (5 .3-6 .2) (14 .4-18 .0) (4.4-4 .9)

1 .5

grai ed sa d .

± s .d.

10

a=43 .3

62

= 6) ra ge

edi

b = 6 .2

c = 18 .0

V = 50 .7%

9

209

251

401

1299

2255

22

43

44

55

57

29

2405 a = 42 .2

b = 6 .0

c = 16 .0

1 .8 ;49%

V = 54 .0% 2 .0 ;54%

BIB , : 49%51%93%

BIB '

49%51%93%

Descrip io Males: lo g, sle der appeara ce, o l sligh l aperi g o ards a erior e d . C icle plai , lacki g arki gs or or a e a io . Lip regio sligh l de arca ed . Lips i h 6 i er al labial papillae a d a circle of 6 e er al labial se ae (6 µ ) + 4 cephalic se ae (5 µ ) . A phideal fo ea c p-shaped, 9 µ i dia e er, 47% of c.b .d . ; loca ed 9 µ fro a erior e d . B ccal ca i 25 µ lo g, 14 µ ide (ra ge : 22-29 X 12-14 µ ) . Pro i e e ros bla eral oo h o righ side ; lef e ros bla eral a d dorsal ee h s all, reachi g id a of he b ccal ca i . Phar c li drical a d sligh l broade ed a base, phar geal al e loca ed a 31 µ fro a erior e d . Cardia dis i c , sc lar, 7 µ lo g .

Ij

i 1i ii

,rr

i; (glp D'I( ril gr ,

pµ("'( p P P'I

IIII IIII ... D-

LL

IIIiIIiI I( .il,IlLII~LIIji

.lILI11~i1L11/II,III///~ /~~

/

4

r

131

Pla e 2 . Viscosiafra ii Bo cher, 1977 2 . Dorsal oo h (la eral ie ) I . A phid (la eral ie ) 5 . Spic le i h 'forked' ip 6 . Media peria a) se ae 3

a,;

a, ; 3 . lef

a, ;

;

e ros bla eral oo h (la eral ie ) a, ; 4 . A 7 . To al ie 62 ; 8 . Tail a2.

phid (la eral ie

) 9,

;

132 Ner e ri g a 59% of phar le g h . Ve ral pore 25 µ behi d er e ri g; e ral gla d cell o righ side of i es i e, 32 µ belo base of phar . Reprod c i e s s e i h o opposed, o s re ched es es, o righ side of i es i e . Vas defere s separa ed fro he sc lar ejac la or d c b a sphi c er (a he le el of he os a erior ca dal gla d cell . Sper a oeboid, 15-23 µ i dia e er . Spic les s raigh , 28 µ lo g i h s all capi l . 12 ada al se ae . Cop la or scle ba ds dis i c , e e di g fro cloaca o os a erior ca dal gla d cell . Three ca dal gla d cells loca ed 141, 153 a d 230, fro cloaca ; he os a erior o e lef of i es i e, he o hers o he righ . Tail s bb i appeara ce, ip de arca ed ; la eral se ae o each side . Fe ales: si ilar o ale e cep i he follo i g : A phideal fo ea 7 µ i dia e er; 32% of c .b .d . B ccal ca i 28 X 12µ (ra ge: 20-29 X 9-13 µ ) . Reprod c i e s s e i h o eq all de eloped bra ches ; bo h o aries a idro o sl refle ed o righ side of i es i e ; de a ia s s e as o ed b Rachor (1969) for Viscosia . O : 92 X 41 µ . Disc ssio

O r speci e s co ple el agree i h he descrip io of V. fra ii b Bo cher (1977), Rie a (1966) a d Blo e (1982) . Bo cher (1977) has ade a al able apical ie of V. fra ii (Fig. 7A) o clarif he e ac posi io of he ee h, b he isi erpre ed he fig re fro poi of ie of he obser er i s ead of fro poi of ie fro he a i al, hich is co o . The larges e ros bla eral oo h is h s si a ed o he righ side (i s ead of lef as described b Bo cher, 1977 p . 751) . The ales e s died had o precloacal ` a elo ' . Vi fra ii is closel rela ed o V. iscosa i ge eral shape; i he r ca e, bi-k obbed (M-shaped accordi g o de Ma , 1890) for of he s aller lef e ros bla eral oo h, a d i he si e of he a phid . Ho e er, i differs fro i b he ore s ro gl de eloped b ccal ca i , i par ic lar he dis i c l larger dorsal oo h, he posi io of he s aller ee h ( id a o he b ccal ca i ) a d he shape of he ail . V. fra ii belo gs o he V. la gr e sis-gro p (S ol, i prep .), charac eri ed b he s all ee h si a ed abo he iddle of a broad b ccal ca i . Wi hi his gro p i is closel rela ed i h V. brach lai a Filipje 1927, V. epapillosa Pla o o a 1971, V. la gr e sis (de Ma , 1890) a d V papillosa (Eber h, 1863) . A o g he V. fra ii is easil recog i ed b he lef s bla eral oo h bei g r ca e (M-shaped) i s ead of sharp .

Viscosia coo

a si sp . .

(Fig . 3 & Pla es 3, 6)

Locali : Lake Gre eli ge , Eas er Scheld , The Ne herla ds Meas re e s

99 ( = 5)

d'd' ( = 5) L a b c C'

V l a Spic les

2706 .4 74 .9 7 .3 17 .5 7 .2

s .d .

ra ge

± 155 .9 ± 6 .5 ± 0 .5 ± 1 .0 ± 0 .8

(2583-2973) (68 .0-84 .9) (7 .0-7 .6) (15 .9-18 .6) (6 .0-7.8)

24 .6 ±

0 .9

(24-25)

s .d . 2953 .4 ± 114 .7 70 .4 ± 8 .3 7 .8 ± 0 .5 17 .9 ± 1 .8 6 .4 ± 0 .7 48 .6 ± 1 .8

ra ge (2833-3071) (60 .3-82 .8) (7 .2-8 .4) (15 .7-20 .7) (5 .6-7 .0) (47 .0-51 .0)

1 33

6 1 (holo pe)

8

177

229

17

37

37

8

198

252

16

33

34

382 35

b=7 .0

24

-

2535 2690

36

20

c=17 .4

9

199

247

380

1457

1925

18

38

39

40

46

28

3071 (slide No . 506)

a=66 .8

9 2(para pe)

2439

37 38 c=17 .9

b=7 .6

a=74 .7

9 1 (allo pe)

-

2583 (slide No . 505) a=68 .0

a2(para pe)

339

b=8 .1

c=21 .0

V=47 .4%

8

198

239

387

1416

2673

17

34

34

37

47

26

2833 a = 60 .3

b = 7 .3

c = 17 .7

2 .1 ; 50%

2 .2 ; 40%

BI a : 38%38%84%

V = 50 .0%

Bl$I

36%36%85%

Descrip io Males: lo g, hi

e a odes aperi g sligh l o ards a erior e d . C icle plai , lacki g or a e a io . Lip regio de arca ed b sligh depressio . 6 i er al labial papillae; 6 e er al labial se ae (5 µ ) a d 4 cephalic se ae (4 µ ) i o e circle . A phideal fo ea c p-shaped, 10 µ i dia e er, 59% of c .b.d ., aper re loca ed 8µ fro a erior e d . B ccal ca i 12 µ lo g, 10 µ ide (ra ge : 20-21 X9-10 µ ) ; pro i e e ros bla eral oo h o righ side . Lef e ros bla eral a d dorsal ee h s all, o reachi g id a he b ccal ca i . Phar sc lar, sligh l ide ed a base . Ner e ri g a 52% of phar geal le g h . Ve ral pore a 34 µ fro er e ri g i h sligh sclero i a io . Ve ral gla d cell o righ side of i es i e, 209 µ fro base of phar . Cardia sc lar, 25 µ lo g . Reprod c i e s s e i h o opposed, o s re ched es es, o righ side of i es i e . Spic les s raigh , 24 µ lo g, hree s all de icles o ip of each spic le. Sper spherical, i h pro i e clei, 8-10 µ i dia e er ; 10 ada al papillae . Cop la or scle ba ds reachi g ill he os a erior ca dal gla d ; he o es i edia el a erior o he cloacal regio ra her obsc re . Three prea al ca dal gla ds : 230, 295 a d 363 µ fro cloacal ope i g; he firs a d hird o lef side of i es i e a d seco d o righ side . Spi ere o er pro i e . Tail aperi g i edia el pos erior o cloacal ope i g b i h sligh s elli g a ip, 144 µ lo g . Fe ales : (o l differe ces dis i g ishi g i fro he ale are gi e ) . B ccal ca i 22 X 9 µ (ra ge : 21-22 X 9-10 µ ) . Reprod c i e s s e i h o eq all de eloped bra ches ; o aries a idro o sl refle ed o righ side of i es i e . V l a si ple, de a ia s s e as described b Rachor (1969) for Viscosia . O : 115 X 31 µ . Disc ssio V. coo a si sp . . is er closel rela ed o V. iscosa Bas ia , 1865 . Bo h ha e he si ilar ee h a a si ilar posi io , b V. coo a si s a ds o b i s larger si e a d high a- al e . Also, he spic les of V. coo a si are s raigh er a d lack he c r a re pical for V. iscosa .

Bo h species are dis i g ished fro he o hers of his ge osi io ed i he seco d half of he b ccal ca i .

sb

he s aller ee h bei g i co spic o s a d

1 34

C

A

50 N

A,B,F, G

F

Fig. 3. Viscosia coo a si sp . . A . Head e d a 1 ; B. Head e d Q I ; C . To al G . Sper cells a2 .

ie

91 ; D . Tail shape, ca dal gla ds 92; E . Ve

ral gla d Q i ; F. Spic lar appara

s ai

135

Pla e 3 . Viscosia coo a si sp . . 1 . A phid (la eral ie ) 6 1 ; 2. Dorsal oo h (la eral ie ) a1 ; 3 . Lef e ros bla eral oo h &, ; 4 . Spic lar appara ( e ral ie ) Y i ; 6 . Dorsal & lef e ros bla eral ee h 91 ; 7 . Tail a1 ; 8 . To al ie a i .

s 61 ; 5 . A

phids

136 Viscosia he erolai

a

sp. .

(Fig. 4 & Pla e 4)

Locali : Eas er Scheld , The Ne herla ds Meas re e s 66 ( =5) ra ge

s .d . 2766 .2 173 .7 114 .6 f 12 .7 7 .1 f 0 .5 21 .6 1 .0 7 .6 0 .8

L a b c c' V l a Spic les

a, (holo

19 .4

f s.d .

(2567-3043) (97 .4-126 .8) (6 .7-7 .8) (20 .7-23 .0) (6 .6-8 .7)

2 .2

2830 .4 ± 96 .1 123 .9 ± 12 .0 8 .1 ± 0 .1 20 .4 ± 1 .3 9 .4 ± 1 .0 43 .0 ± 2 .6

9

192

251

412

-

18

23

23

23

24

2913 3043 (slide No . 507)

a=126 .8

b=7 .4

16

-c=23 .4

11

185

318

404

20

24

24

24

-

2583 2714

a=113 .1

b=6 .7

24

18

c = 20 .7

6

162

183

335

1065

2575

13

19

19

20

23

14

9, (allo pe)

2719 (slide No . 508) a=118 .2

b=8 .1

c=18 .9

V=39 .2%

6

157

205

342

1193

2606

13

20

21

21

22

16

92 (para pe)

2739 a=124 .5

b=8 .0

c=20 .6

1 .9 ;47% 66%59%81%

V=43 .6% 1 .8 ;27%

BIB

Descrip io Males : lo

(2719-2938) (113 .0-144 .1) (8 .1-8 .2) (18 .9-22 .5) (8 .3-10 .4) (39-46)

(16-22)

pe)

62 (para pe)

99 ( = 5) ra ge

BI~ I

36%41%91%

g, sle der bod , of e c r ed . C icle plai , lacki g or a e a io . Lip regio de arca ed b a sligh depressio . 6 i er labial papillae a d 6 o er labial (5 µ ) + 4 cephalic se ae (4 µ lo g) . A phideal fo ea c p-shaped, 7 µ ide, 43% of c .b .d . ; aper re si a ed 6 µ fro a erior e d . B ccal ca i 21 µ lo g a d 11 µ ide (ra ge : 24-25 X 13 µ ) . Large e ros bla eral oo h loca ed o righ side a d reachi g ill 5 µ fro a erior e d ; lef e ros bla eral oo h a d dorsal oo h sharp, posi io ed i he a erior os par of he b ccal ca i . Phar arro hro gho i s le g h, sligh l broader a base .

137 Ner e ri g a 46% of phar geal le g h . Ve ral pore a 27 µ behi d er e ri g ; bo o of e ral gla d cell loca ed a 146 µ fro he base of he phar , o righ side of i es i e . Cardia sc lar, 13 µ lo g . Reprod c i e s s e i h o opposed, o s re ched es es ; sper spherical 10-11 µ i dia e er . Spic les s raigh , 20 µ lo g. Three ca dal gla ds loca ed 144, 179 a d 183 µ fro cloacal ope i g; he firs o e o he lef of he i es i e, he seco d a d hird o e o he righ side . Ada al area i h 3 pro i e pairs a d o e si gle i e se a, loca ed o he edge of a ala . Tail arro i g shor l behi d cloacal ope i g, c li drical hro gho i s le g h ; la ero- e rall here are 8 s all se ae . Fe ales: si ilar o he ales e cep i he follo i g respec s : O er labial se ae (8 µ ) + cephalic se ae (7 µ ) lo ger. B ccal ca i 15 X 7 µ (ra ge : 15-17 X 6-8 µ ) . Large righ e ros bla eral oo h reachi g al os o he ip of he b ccal ca i . T o s aller ee h (lef e ros bla eral a d dorsal ee h) o reachi g o he iddle of he b ccal ca i a d bl . A phids 5 µ ide, 41% of c.b .d . loca ed a 5 µ fro a erior e d . Reprod c i e s s e i h o a idro o sl refle ed o aries, o righ side of he i es i e ; ger i ae o e of refle ed par of pos erior bra ch reaches a erior o he l a . De a ia s s e ' iscosioid', os osi a a larger dis a ce fro he o ari ha i he o her species described . O : 21-22 µ X 129-133 µ . Disc ssio V. he erolai a sp . . is charac eri ed b a se al di orphis i he si e a d posi io of he ee h i he b ccal ca i . While he large righ e ros bla eral oo h reaches al os he a erior e d i he fe ale, i s ip is si a ed f r her back i he ale . F r her ore he s all ee h are poi ed i he ale a d reach he firs half of he b ccal ca i , b are bl i he fe ale a d are si a ed i hi he seco d half of he b ccal ca i . Accordi g o his V. he erolai a sp . . has a i er edia e posi io be ee he Viscosia-gro ps (see also S ol, i prep .) . The o er labial a d cephalic se ae of he fe ale are lo ger ha hose of he ale . The fe ale ail is also lo ger as e ide ced b he higher c'-i de . V. he erolai a sp . ., oge her i h V. elo ga a Filipje , 1922, a d V. e issi a, Allge , 1959 are recog i ed as lo g filifor Viscosia-species, charac eri ed b a a-ra io >, 100 . V. he erolai a a d V. elo ga a differ fro V. e issi a b ha i g he righ e ros bla eral oo h bei g he larges i s ead of he lef o e . The fe ale speci e s of V. he erolai a are er close o he fe ale of V. elo ga a as described b Filipje , 1922 . Filipje based his descrip io o o l o e fe ale, fo d i he Black Sea . Whe redescribi g i , Sch r a s-S ekho e (1950) based his descrip io o a si gle ale fo d i he Medi erra ea Sea, b did s gges a se al di orphis i he a phid si e . The ale speci e s of V. he erolai a described here differ co siderabl fro he ale of V. elo ga a as described b Sch r a s-S ekho e (1950), especiall i he si e a d posi io of he s aller ee h . I he peria al regio ales of V. elo ga a lack a race of pro i e ala a d ha e lo ger peria al se ae . Whe her he ale of V. elo ga a described b Sch r a s-S ekho e (1950) is co specific or o i h he fe ale of V. elo ga a described b Filipje (1922) is clear for he o e . U il ore a erial is fo d a he pe locali ies o el cida e his proble , e propose V. he erolai a as a e species .

138

D E

I

200 N

I {

100 N G, H I 50p

1 I i

A .B .D .E .F Fig. 4 . Viscosia he erolai a A . Head e d 9 1 ; B. Head e G . Spic lar appara

s( e

sp. . d $i ; C . Ve ral gla d 9i ; D . Tail shape a, ; E . Tail shape 9I ; F . Spic lar appara ral ie ) 63 ; H . Sper cells &, ; I . To al ie 9i ; J . V l ar regio 4,

s (la eral

ie ) a'1

139

Pla e 4 . Viscosia he erolai a sp . . 1 . A phid (la eral ie ) 61 ;2 . Dorsal oo h (la eral ie ) 6 1 ; 3 . Lef e ros bla eral oo h (la eral ie ) 6 1 ;4 . A phid (la eral ie ) Y I ; e ros bla eral oo h (la eral ie ) 9 1 ; 7 . Spic lar appara s a, ; 8 . To al ie 62; 5 . Dorsal oo h (la eral ie ) 9 1 ; 6 . Lef 9 . To al ie 91 ; 10 . Tail a2 .

1 40 Viscosia iscosa (Bas ia , 1865) s . o . : Mo o cholai s iscos s Allge , 1930 Mo o cholai s elega s se s Sch r

(Figs . 5 & 6 a d Pla e 5) a s-S ekho e

1942, 1950

Locali : Die e ga , Belgi Meas re e s

66 ( R L a b c c' V l a Spic les

61

± s .d .

1728 .1 ± 41 .6 38 .7 ± 6 .2 6 .2 ± 2 .5 17 .8 ± 4 .2 4 .9 ± 2 .2

168

205

15

34

33

15

b=6 .3

a=54 .4

1897 .4 ± 43 .6 52 .2 ± 7 .2 6 .3 ± 2 .5 17 .1 ± 4 .1 5 .3 ± 2 .3 49 .9 ± 7 .1

(1453-2291) (38 .2-66 .2) (5 .2-7 .3) (14 .4-20 .6) (5 .1-6 .1) (46-61)

34 b=6 .2

301

-

35 35 c=17 .4 309 35 c=19 .4

1788 21

35

1806 21

6

167

210

280

847

1687

16

34

35

39

39

21

1897 (slide No . 509)

1904

1799 (slide No. 510)

91

a=46 .1

92

198

168 33

99( =10) ra ge

(26-31)

7

7 162

± s .d .

(1372-2051) (37 .4-60 .3) (5 .7-6 .9) (15 .3-19 .9) (4 .3-5 .4)

28 .6 ± 5 .3

a=54 .2

=10) ra ge

(gra id)

6 15

b=6 .4

179 34

a=58 .3 2

213 36 b=7 .2

c=16 .1 315 39 c=20 .3

;43%

BI a :

Big, 46%46%96%

Descrip io Males: bod sle der, filifor

V=47 .1% 1065

2163 2275

22 39 V=46 .8% 1 .8 ;41% 38%41%90%

, aperi g sligh l a eriorl . Ma i id h alread reached a he e d of he phar . C icle s oo h. Sca ered se ae o er he bod . Lip regio sligh l de arca ed . Lips i h 6 i e i er al labial papillae a d 10 se ae: 6 e er al labial (7 µ ) a d 4 cephalic (6 µ ) . A phids i h c p-shaped fo ea a d o al aper re, 9 µ ide (55-60% of c.b .d .) a d si a ed a 5 µ fro he a erior e d .

141 B ccal ca i i h hea il sclero i ed alls, 17 µ deep, 9 µ ide (ra ge: 17-19 X 9-10 µ ) . Large e ros bla eral oo h o he righ side, sharp, ape reachi g a erior o he le el of he se ae . Lef e ros bla eral oo h eakl sclero i ed, picall M-shaped i la eral ie , ape behi d he iddle of he b ccal ca i . Dorsal oo h s all, see as a s all ele a io of he dorsal all ; si a ed a he sa e le el as he s all e ros bla eral oo h . Phar c li drical, i i s fore os par he l e is pro ided i h a al e . Ner e ri g co spic o s, si a ed sligh l behi d he iddle (± 55%) of he phar . Ve ral pore abo 35 µ pos erior o er e ri g ; e ral gla d pos phar geal, o he righ side of he i es i e, pos erior argi abo 200 µ fro he base of he phar . Cardia pro i e , ria g lar, 21 µ lo g . Reprod c i e s s e i h o opposed, o s re ched es es . Vas defere s separa ed fro he sc lar ejac la or d c b a sphi c er (Fig . 5E, H) a he le el of seco d ca dal gla d . Spic les picall c r ed, sligh l cephala ed, dis all `forked', le g h 1 .5 X a .b .d . 5 pairs of peria al se ae prese . G ber ac l abse . Tail co oid i pro i al par a d c li drical ore pos eriorl , c r ed e rall , pro ided i h se ae . A pical co s ric io a d s bseq e ide i g i he ail is obser ed (cf. Rie a , 1966) (Pla e 6) . Ca dal gla ds i h prea al cell bodies, loca ed 147,294 a d 368 µ fro cloacal ope i g, he a erior os o e o he righ side, he o o her o he lef side . Fe ales: i ge eral si ilar o he ales, al ho gh larger . Reprod c i e s s e i h o eq all de eloped bra ches ; a idro o sl refle ed o aries o he righ side of i es i e . A a i of fo r eggs as obser ed i he er s ; eggs eas ri g 76-130 X 24-28 µ . De a ia s s e pical for he ge s (cf. Rachor, 1969) i h a elo ga io of he o arial sac a d a os osi . Tail de oid of se ae . J

e iles Ji (

L a

b c

= 3)

K

± s .d .

502 .0 29 .3 3 .0 6 .0

± ± ± ±

1 .7 3 .6 0 .1 0 .9

J 2 ( = 7) ra ge

± s .d .

(500-503) 744 .0 ± 69 .0 (25 .2-31 .4) 33 .4 ± 3 .0 (2 .9-3 .1) 4 .0 ± 0 .2 (5 .4-7 .0) 10 .0 ± 1 .0

J3 ( = 10) ra ge

± s .d .

(617-819) 1108 .4 ± 70 .4 (30 .3-38 .3) 39 .4 ± 6 .7 (3 .7-4 .4) 4 .8 ± 0 .3 (8 .5-11 .5) 12 .7 ± 1 .1

J4 ( = 10) ra ge

± s .d .

ra ge

(1047-1241) 1584 .9 ± 134 .5 (1435-1876) (31 .6-51 .1) 48 .7 ± 5 .9 (39 .0-59 .9) (4 .3-5 .3) 5 .9 ± 0 .6 (5 .1-6 .9) (11 .5-14 .6) 15 .6 ± 1 .3 (13 .9-17 .8)

J 1 (Fig . 6 :A, J & K)

Bod less sle der ha ha of he ad l s ; a i id h a he le el of he phar ; clearl aperi g behi d he base of he phar . Head e d : papillae diffic l o see, se ae 3 µ lo g . Wi h he ligh icroscope i as diffic l o de er i e he her o er labial se ae a d cephalic se ae ere separa ed i o circle s or o . B ccal ca i arro a d lo g, abo 3 i es as lo g as ide . A firs sigh o l he large righ e ros bla eral oo h as dis i c , b caref l e a i a io re ealed he e is e ce of a dorsal oo h a d a s all lef e ros bla eral oo h . Phar geal al e, er e ri g a d e ral gla d as i he ad l s ; e ral pore i co spic o s . A phideal fo ea large a d deep: 4 µ = 45% c .b .d . Tail less pro i e . Ca dal gla ds i a de . Ge i al pri ordi co sis i g of o o al bodies co ec ed b a s ra d of iss e, l i g a abo 250 µ fro he a erior e d . Each o al bod co ai s a si gle large ce rall loca ed spherical ger i al cle s a d o s aller so a ic clei . To al le g h of he pri ordia is abo 41 µ .

1 42

Fig. 5 . Viscosia iscosa (Bas ia , 1865) A . To al ie 92 ; B . Head e d C . Head e d Yi ; D . Phar geal regio , F. Head e d 92 ; G . Spic lar appara s ai ; H . To al ie 61 ; I . Sper cells ai .

a, ;

e

ral gla d 61 ; E. Tail shape, ca dal gla ds

a, ;

1 43

Pla e S. Viscosia iscosa (Bas ia , 1865) I . A phid (la eral ie ) 2 . Dorsal oo h (la eral ie ) c r ed spic le 6 1 ; 5 . To al ie 61 ; 6 . Tail i h co s ric io s

a, ;

a,; 3 . Lef

a,.

e

ros bla eral oo h (la eral

ie )

ai; 4 . Spic

lar appara

s:

1 44 J2

(Figs . 6 : B, I & L) This s age is recog i ed b i s lo ger si e a d he de elop e of he ge i al pri ordia . The a-, b-, & c-i de i creases . The a phid is larger a d co s i es ore ha 50% of he c .b .d . The b ccal ca i is abo 2 .5 i es as lo g as ide. The ca dal gla ds lie fairl close o each o her. Wi hi his s age he ber of clei is do bli g. J 3 (Fig . 6 : C, H & M) The bod is ore or less of eq al id h hro gho i s le g h The b ccal ca i broade s a d beco es ice as lo g as ide; i s shape is si ilar o ha of he ad l s . l iplica io of bo h he ger i al a d so a ic cells, b The ge i al pri ordia e large probabl b i g ech iq es, i is i possible o dis i g ish be ee bo h pes of cells . i ho si g s ai Se es ca be recog i ed . I he case of fe ales, cells are gro ped aro d he f re agi a ; i he case of ales spic lar pri ordial cells are arra ged a he dorsal all of he rec . J4 (Fig. 6 : D, E, F, G, N & 0) Al ho gh s aller, bod shape a d head e d are er si ilar o hose of he ad l s . Ge i al rac clearl isible, e larged ; l a a d spic lar pri ordia er dis i c . Disc ssio Viscosia iscosa

as firs described b Bas ia i 1865 as O cholai s iscos s. This descrip io a d especiall he dra i gs are er poor . His eas re e s co ple el agree i h o r speci e s, b he dra i g of he b ccal ca i disagrees as here are 3 pro i e ee h sho , of hich he 2 large o es are of eq al le g h . This pa er is repea ed for o her o cholai ids as ell . As his is o i accorda ce i h he diag os ic charac er of o e large e ros bla eral oo h a d o s all ee h; e s ppose ha he dra i gs lack acc rac a d e refer o he eas re e s as a basis o ide if o r speci e s as V. iscosa as described b de Ma (1890) . V. iscosa is charac eri ed b a pro i e righ e ros bla eral oo h a d a i co spic o s M-shaped lef e ros bla eral oo h . This M-shaped s all oo h is q i e s al a o g he ero s Viscosia-species ol, i prep.) . Accordi g o his V. iscosa is os (see S closel rela ed o V fra ii Bo cher (1977) a d V. coo a si sp . . Wi h V. coo a si i shares he i e ee h (dorsal a d lef e ros bla eral) posi io ed pos erior o he iddle of he b ccal ca i , b V. coo a si is ch lo ger a d has s raigh er spic les. V. iscosa is rela ed o V. fra ii i si e a d ge eral shape, b differs i he posi io a d si e of he s all ee h : he dorsal oo h bei g ore pro i e a d posi io ed ore a eriorl i V. fra ii ( id a b ccal ca i ) ; a d i he shape of he ail ( pical co s ric io for V. iscosa) a d i he shape of he spic le hich is picall c r ed i V. iscosa . We s o i e Mo o cholai s iscos s Allge , 1930 i h V. iscosa as he eas re e s of he o l i hi he ra ge of o r j e iles, a d he i dices prese ed b Allge j e ile described falls co ple el (1930) are er close o hose of a speci e i h co parable le g h . I is clear ha Allge has o erlooked he o s all ee h, hich are i deed i e . Moreo er, his j e ile as also fo d i a brackish a er habi a as is he case for V. iscosa . Wieser (1953, p . 105) co siders Mo o cholai s elega s se s Sch r a s-S ekho e , 1942,1950 o be a s o of Mo o cholai s iscos s Allge , 1930, based o he prese ce of a a phid ( hich is lacki g i Mo o cholai s elega s Kreis, 1924) . We do agree i h Wieser (1953) b for a differe reaso ; e ca o co sider he ales of Mo o cholai s elega s described b Sch r a s-S ekho e (1942, 1950) i ho a g ber ac l o be s o o s o he ales of M. elega s described b Kreis (1924) a d depic ed i h a g ber ac l . This arg e has also bee disc ssed b Vi iello (1970, p . 196) . We do agree i h Wieser (1953) a d Vi iello (1970) a d co sider Mo o cholai s elega s se s Sch r a s-S ekho e , 1942,1950 as differe fro Mo o cholai s elega s Kreis, 1924 . The erical da a of he for er co ple el agree i h o r da a for V. iscosa a d herefore Mo o cholai s elega s se s Sch r a s-S ekho e , 1942, 1950 ( ec. Kreis, 1924), fo d i he Ca arg e (brackish) is s o i ed i h V. iscosa (Bas ia , 1865) .

0

L K

Fig. 6 . Viscosia iscosa (Bas ia , 1865) A . J i : head e d ; B . J 2: head e d ; C . J 3 : head e d ; D. J 4: head e d (Y) ; E . J 4 : head e d (a); F. J i : ail; G . J 2: ail; H . J 3 : ail; I. J 4: ail (Q); J. J 4 : ail ((3) ; K . J j : ge i al pri ordia ; L . J 2 : ge i al pri ordia; M . J 3 : ge i al pri ordia; N . J 4: ge i al pri ordia (s) ; 0 . J 4 : ge i al pri orida (9) .

1 46

Pla e 6. De I . Os osi

a ia s s e of V. coo a si (la eral ie ) 9 1 ; 2 . Os

osi

of V. coo

a si ( e

ral ie ) 92; 3 . Os

osi

of V. fra

ii (la eral ie )

9

147 Ack o ledge e s The a hors ack o ledge he help of Wilfried Decrae er for he dra i gs, Rose-Marie Ser aes for he de elop e a d reprod c io of he pho ographs a d Mar i e De Wi e for he pi g of he a scrip . We o ld like o e press special gra i de o Prof. Dr . A . Coo a s a d Magda Vi c for helpf l disc ssio a d cri icis of he a scrip .

Refere ces Allge , C, 1950a . Le er Berich ber freilebe de Ne a ode o der Ca pbelli sel. Zool . A . 145: 309-316 . Allge , C ., 1959 . Freeli i g ari e e a odes . F r her ool . Res l s S ed . A arc . E ped . 5(2) : 1-293 . Bas ia , H, Ch ., 1865 . Mo ograph o he A g ill lidae, or free Ne a oids, ari e, la d, a d fresh a er; i h descrip io s of 100 e species . Tra s. Li . Soc . Lo do 25 : 73-184 . Belog ro , O . I . & L . S . Belog ro a, 1977 . Morpholog of Viscosia poseido ica sp . o . a d Viscosia sie os o a Plao o a, 1971 (Ne a oda, O cholai idae) - Free-li i g e a odes fro he area of F r gel a Isla ds. Biological Scie ces 6 : 44-47 . Blo e, D ., 1982 . S s e a ik der Ne a oda ei es Sa ds ra des der Nordseei sel S l . Mikrofa a Meeresbode 86 : 1-194 . Bo cher, G ., 1977 . Ne a odes des sables fi s i frali ora de la Pierre Noire (Ma che occide ale) . I V . E oplida . B ll . M s . a . His . a ., Paris, 3e serie, o . 468, Zool. 325 : 733-752 . Coo a s, A, 1978 . A proposal for a ore precise er i olog of he bod regio s i he e a odes . A . Soc . r. ool . Belg. 108 :115-117 . Chi ood, B . G ., 1951 . Nor h A erica ari e e a odes . Te . J . Sci . 3 : 617-672 . De Grisse, A ., 1965 . A labo r-sa i g e hod for fi i g a d ra sferri g eel or s o a h dro s gl ceri . La dbHogesch .

Kreis, H ., 1924 . Z r Ke is der freilebe de ari e Ne a ode . Schrif e f r S b asser a d Meeresk de, B s 2: 157-170 . Kreis, H ., 1932 . Freilebe de ari e Ne a ode o de S daI sel . II . O cholai i ae . (Papers fro Dr . Th . More se 's Pacific E pedi io 1914-16, 61) . Vide sk. Meddr da sk a rh . Fore . 93 : 23-69 . Pla o o a, T. A ., 1971 . Freeli i g ari e Ne a odes fro he Possje Ba of he Sea of Japa . Isledo a ija fa i orjei 8 (16) - Fa a i flora ali a Posje a japo sko o orja: 72-108 . Rachor, E ., 1969 . Das de Ma sche orga der O cholai idae; ei e ge i o-i es i ale erbi d g bei Ne a ode . Z. Morph . Tiere 66 : 87-166 . Rie a , F., 1966 . Die i ers i ielle Fa a i Elbe-Aes ar . Verbrei g a d S s e a ik. Arch. H drobiol ., S ppl . 31 : 1-279 . Sch r a s-S ekho e , J . H ., 1942 . The free-li i g e a odes of he Medi erra ea . III . The Ca arg e . Zool. Meded., Leide 23 : 217-228 . Sch r a s-S ekho e , J . H ., 1950 . The freeli i g ari e eas of he Medi erra ea . I . The Ba of Villefra che . Me .

Op oekS s - Leers oel Dierk . Ge : 4 pp. De Ma , J . G ., 1980 . Q a rie e o e s r les Ne a odes libres de la e d Nord e de la Ma che . Me . Soc. ool . Fr . 3 : 169-194 . Di le se , Hj ., 1921 . Mari e free-I i g e a odes fro he A ckla d a d Ca pbell Isla ds . (Papers fro Dr . Th. More se 's Pacific E pedi io 1914-16 III) . Vide sk . Meddr . da sk a rh. Fore . 73 : 1-32 . Eber h, C . 1 ., 1863 . U ers ch ge ber Ne a ode . Leip ig (W . E gel a ) 1863 : 1-77 . Filipje , 1 ., 1922 . E core s r les Ne a odes libres de la Me Noire . Tr d s a ropol'sel' . Kho . I s . 1 : 83-184 . Filipje ,1 ., 1927 . Les Ne a odes libres des ers sep e rio ales appar e a A la fa ille des E oplidae. Arch. Na rgesch .

I s . r . Sci. a . Belg . (2)37: 1-220 . Sei hors , J . W ., 1959 . A rapid e hod for he ra sfer of e a odes fro fi a i e o a h dro s gl ceri . Ne a ologica 4 : 67-69 . S ol, N . A re ie of he ge s Viscosia de Ma , 1890 (Ne a oda, O cholai idae) . H drobiologia (i prep .). S ol, N ., Heip, C . & Go aer , M ., 1981 . The life c cle of O cholai s o ris (Ne a oda) i i s habi a . A ales Soc. r . Zool. Belg . 110 : 87-103 . Vi iello, P ., 1970 . Ne a odes fibres a i s des ases profo des d Golfe d Lio . I . E oplida Te h s 2 : 139-210 . Wieser, W . & Hopper, B ., 1967 . Mari e e a odes of he eas coas of Nor h A erica . I . Florida B ll . M s . co p. Zool . Har . 135 : 239-344 . Wieser, W ., 1953 . Free-li i g ari e e a odes I . E oploidea . Ac a U i . L d. (N . F. 2) 49 (6) : 1-155 .

91 A (6) : 1-216. Gerlach, S . A ., 1957 . Mari e Ne a ode a s de Ma gro eGebie o Ca a eia (Brasilia ische Meeres-Ne a ode III) . A bh . a h.- a r . Kl . Akad . Wiss . Mai 5 :129-176 .

Recei ed 3 March 1983 ; accep ed 22 A g s 1983 .