Bull. Mus. nain. Hist. nat., Paris, 4 e sér., 2, 1980,

section A , n° 3 : 707-718.

A revision of the genus Oxysomatium Railliet & Henry, ]916

(Nematoda, Cosmocercidae)

b y M i c h a el R. B A K E R *

Résumé. — Révision du genre O x y s o m a t i um Railliet (f Henry, 1916 [Nematoda, Cosmocer-cidae). — Le genre Neoxysomatium Bal lesteros-Mârquez, 1945, est s ynonyme A'Oxysomatium Bail l iet & Henry, 1916 ; ces deux genres ont la m ê me espèce- type. Oxysomatium comprend trois espèces : O. brevicaudatum (Zeder, 1800) [ = O. contortum (L ins tow, 1906) Bayl is, 1927 ; = O. longe-spiculum Rail l iet & Henry, 1916] ; O. caucasicum (Sharpi lo, 1974) n. c o m b. [ = Neoxysomatium caucasicum et O. dollfusi n. sp. O. dollfusi se dist ingue des autres espèces par les dimensions et la morpho log ie des spicules et par la répart i t ion géographique. Toutes les autres espèces classées p récédemment dans ce genre do ivent être assignées à des genres différents. La femelle ^Oxysoma-tium waltoni Skrjabin, Sch ikhoba lova & M o z g o v o i, 1951, est inconnue et cette espèce est laissée incertae sedis. Oxysomatium dogieli Skrjabin, 1916, est species dubia. O. tibetanum Bayl is, 1927, est transféré dans le genre Cosmocercoides et O. baylisi Wa l ton, 1933, est transféré dans le genre Railliet' nema. Oxysomatium georgianum Reiber, By rd & Parker, 1940, est un synonyme de Cosmocercoides dukae (Ho l l ) .

Abs t rac t. — The genus Neoxysomatium Bal lesteros-Mârquez, 1945, is shown to be synonymous wit h Oxysomatium Rail l iet & Henry, since the type species are the same. Oxysomatium contains only the three fo l lowing species : O. brevicaudatum (Zeder, 1800) [ = O. contortum (L ins tow, 1906) Bayl is, 1927 ; = O. longespiculum Rail l iet & Henry, 1916] ; O. caucasicum (Sharpi lo, 1974) n. c o m b. [= Neoxysomatium caucasicum] ; O. dollfusi n. sp. O. dollfusi differs f rom the other two species in the size and morpho logy of the spicules and in geographical distr ibut ion. Ai l other species pre-v ious ly assigned to Oxysomatium be long in other gênera. Oxysomatium waltoni Skrjabin, Schikho-ba lova & Mozgovo i, 1951, is known only f rom maies and it is left incertae sedis. Oxysomatium dogieli Skrjabin, 1916, is designated a species dubia. O. tibetanum Bayl is, 1927, is transferred to Cosmocercoides and O. baylisi Wa l ton, 1933, is transferred to Raillietnema. Oxysomatium georgia-num Reiber, By rd & Parker, 1940, is a s y n o n ym of Cosmocercoides dukae (Ho l l ) .

The re has b e en m u ch c o n f u s i on c o n c e r n i ng gênera i n t he S u b f a m i ly C o s m o c e r c i n ae

( C o s m o c e r c o i d e a ). Cosmocerca, Cosmocercella a nd Cosmocercoides are eas i ly r e c o g n i z ed by

the ir d i s t i nc t i ve ma ie c a u d al pap i l l ae and Raillietnema by its r e l a t i ve ly la rge eggs w h i ch

are a l w a ys f ew in n u m b er in the uter i. H o w e v e r, Oxysomatium, Neoxysomatium a nd Aplec-

tana are n ot eas i ly d i f fe ren t ia ted a nd n u m e r o us d i f férent d i agnoses h a ve b e en p r o p o s ed

b y va r i ous au tho rs. I m p o r t a nt cha rac te rs h a ve n ot b e en d e s c r i b ed in m a ny spec ies.

A rev i s i on of th is c o m p l ex of gênera has b e en u n d e r t a k en a nd s p é c i m e ns of n u m e r o us

spec ies h a ve b e en e x a m i n e d. In the p résent s t u dy the gênera Oxysomatium a nd Neoxyso-

matium are rev i sed ; Aplectana w i l l be s im i la r ly t rea ted in a separa te p u b l i c a t i o n.

* Laboratoire de Zoologie (Vers) associé au CNRS, Muséum national d'Histoire naturelle, 43, rue Cuvier, 75231 Paris Cedex 05.

— 708

MATERIAL S AND METHOD S : Spécimens were bor rowed f rom var ious Insti tut ions. The fo l low-ing abbreviat ions have been used : B M , Brit ish Muséum (Natural History) ; C I H, Commonwea l th Institute of He lm in tho logy ; Z M B , Zoolog ischen Muséums Berlin ; M N H N , Muséum national d 'Histo i re naturelle ; U S N M, United States Nat ional Muséum.

R E S U L TS

T he first p u b l i c a t i on of the n a me Oxysomatium w as in a f o o t n o te in a p a p er by R A I L -

LIE T & H E N R Y w h i ch w as p resen ted at a c o n f é r e n ce in 1913 b ut n ot p u b l i s h ed unt il 1914.

I n the p u b l i s h ed t e xt Oxysomatium lepturum w as b r ie f ly m e n t i o n ed as a spec ies possess ing

a p reanal sucke r. T h is c a n n ot be c o n s i d e r ed a v a l id p r o p o s ai of the gener ic n a me Oxyso-

matium. T he n a me Oxysomatium w as n ot f o r m a l ly p r o p o s ed as a r e p l a c e m e nt n a me for

Oxysoma Schne ide r, 1866 ( p r e o c c u p i e d ), unt il RAILL IE T & H E N R Y ( 1916a) c lea r ly s ta ted

t h at Oxysomatium brevicaudatum ( Z e d e r, 1800) [ = Fusaria brevicaudata Z e d e r] was the

t y pe spec ies of Oxysomatium Ra i l l i et & H e n r y, 1 9 1 3. I t is l i ke l y f r om the i n t r o d u c t i on

t o th is 1 9 1 6a ar t ic le t h at RAILL IE T & H E N R Y k n ew as ea r ly as 1913 t h at Oxysoma w as

p r e o c c u p i ed a nd t h ey d e c i d ed t h en on Oxysomatium as a r e p l a c e m e nt n a m e. Th is exp la ins

t he a p p a r e n t ly a n o m a l o us ré fé rence to the n a me Oxysomatium i n the ir 1914 paper. T he

c o r r e ct a u t h or a nd da te c i t a t i on s h o u ld be Oxysomatium Ra i l l i et & H e n r y, 1916.

T he genus Neoxysomalium Ba l l es te ros -Mârquez, 1945, was es tab l i shed w i t h Fusaria

brevicaudata [= Oxysomatium brevicaudatum ( Z e d e r, 1800) Ra i l l i et & H e n r y, 1916] as

t y pe spec ies. BALLESTEROS-MÂRQUE Z b e l i e v ed at t hat t ime t hat Oxysomatium longes-

piculum Ra i l l i et & H e n r y, 1916, a nd Fusaria brevicaudata Z e d er we re separa te spec ies.

A s s h o wn b e l ow this is i n c o r r e ct a nd Neoxysomatium is a s y n o n ym of Oxysomatium.

EMENDE D DIAGNOSI S OF Oxysomatium

Oxysoma Schneider, 1866 (preoccup ied). Neoxysomatium Bal lesteros-Mârquez, 1945.

Cosmocerc inae sensu Chabaud, 1978, Cosmocerc idae, Cosmocerco idea, Ascar id ida. Tail of maie lack ing rosettes or plectanes. Somat ic papi l lae and latéral alae présent. Uteri wi th numer-ous thin-shelled, relat ively small eggs. Ovary of anterior utérus located just poster ior to vu lva, ova ry of poster ior utérus located well anterior to vu lva.

TYPE-SPECIES : Oxysomatium brevicaudatum (Zeder, 1800) Rai l l iet & Henry, 1916.

Oxysomatium m o st c l ose ly r esemb les Aplectana. Thèse gênera m ay be d i f fe rent ia ted

b y the l o c a t i on of t he t w o ova r i es. In Aplectana b o th are an te r ior t o t he v u l v a, whe reas

i n Oxysomatium the o v a ry c o n n e c t ed to t he an te r ior u té rus is pos te r i or to t he v u l v a. F or

th is c h a r a c t er Aplectana has b e en d e s c r i b ed as " p r o d e l p h ic " a nd Oxysomatium as " a m p h i-

d e l p h ic " (see CHABAUD , 1 9 7 8 ). Th is t e r m i n o l o gy is n ot f o l l o w ed here in b e c a u se of a m b i-

g u i ty i n t he dé f in i t i on of the t e r m s. F or e x a m p l e, in t he o r ig inal dé f in i t i on p r o p o s ed

b y SEURAT ( 1 9 2 0 ), o ne of t he e x a m p l es g i v en of an a m p h i d e l p h ic spec ies, n a m e ly Haemon-

chus ( T r i c h o s t r o n g y l o i d e a ), is in i t s a r r a n g e m e nt of u teri a nd ova r ies s imi lar to Aplectana.

— 709 —

SPECIES

1. Oxysomatium brevicaudatum (Zeder, 1800) Rail l iet & Henry, 1916

Fusaria brevicaudata Zeder, 1800. Ascaris brevicaudata (Zeder, 1800) Rudo lph i, 1802. Oxyuris brevicaudata (Zeder, 1800) Dugès, 1826, nec Dujardin, 1845. Heteracis brevicaudata (Zeder, 1800) Diesing, 1861, nec Dujardin, 1845. Oxysoma brevicaudata (Zeder, 1800) Schneider, 1866. Aplecta brevicaudata (Zeder, 1800) Rail l iet & Henry, 1916. Aplectana brevicaudata (Zeder, 1800) Rail l iet & Henry, 1916. Neoxysomatium brevicaudatum (Zeder, 1800) Bal lesteros-Mârquez, 1945. Oxysomatium longespiculum Rai l l iet & Henry, 1916. Oxysoma contortum L ins tow, 1906. Oxysomatium contortum (L ins tow, 1906) Bayl is, 1927. Aplectana contorta (L ins tow, 1906) Yo rke & Maplestone, 1926. Neoxysomatium contortum (L ins tow, 1906) Bal lesteros-Mârquez, 1945.

REDESCRIPTIO N ( f igs. 1-2)

La té ral a lae n a r r o w, s o m a t ic pap i l l ae n ot n u m e r o u s. Cu t i c le of b o dy w i t h i n c o n s-

p i c u o us t ransverse s t r ia t ions a p p r o x i m a t e ly 3.5 [xm apar t. Oral o p e n i ng t r iangu lar, l ip s

la rge. Cepha l ic pap i l l ae i n c l u de 6 small lab ial pap i l l ae a nd s ix c e p h a l ic pap i l l ae of w h i ch

the s u b m e d i an pa ir is m a r k e d ly smal l. A n t e r i or e x t r e m i ty of o e s o p h a g us w i t h th ree

t o o t h - l i ke p r o j e c t i o ns c o v e r ed w i t h t h i ck cu t i c l e.

Maie (Bufo, D e n m a r k, 5 s p é c i m e n s) : T o t al l eng th 5 .0-6 .9 m m. L e n g th of oesophagus

750 -878 (xm ( p h a r y n g e al p o r t i on 53 -69 [xm, pos te r i or p o r t i on of c o r p us 5 6 6 - 6 66 jxm, i s t h m us

31 -41 [xm, a nd b u lb 9 7 - 1 09 [xm). N e r ve r ing 3 5 6 - 4 22 [xm and e x c r e t o ry p o re 4 4 7 - 5 63 [ir a

f r om an te r ior e x t r e m i t y. Ta il 1 5 3 - 1 72 [xm l o n g, t ape r i ng r a p i d ly to l o ng p o i n t ed t e rm inal

p o r t i o n. A n us w i d e, o p e n i ng o n to m a r k ed swe l l i ng on ven t ral sur face. La té ral a lae

e x t e n d i ng f r om a b o ut 100 jxm an te r i or to anus to m i d - r e g i on of oesophagus. C a u d al

pap i l l ae la rger t h an s o m a t ic pap i l l ae. P o s t e r i or ha lf of tail w i t h t w o large s u b v e n t r al

and t w o large s u b d o r s al pai rs of pap i l l ae ; s u b v e n t r al pairs o f ten n ot a l i gned d i r e c t ly

o p p o s i te e a c h o t h e r. A n t e r i or half of ta il w i t h th ree pai rs of pap i l lae ; t w o pai rs s u b v e n t r a l,

o ne pa ir sub la te ra l. A n t e r i or l i p of anus w i t h o ne unpa i r cd pap i l la w h i ch is s u p p o r t ed

b y a cu t i cu l ar c u p - s h a p ed s t ruc tu re p r o v i d ed w i t h la te ra l ly d i rec ted w ing - l i k e e x t e n s i o ns

j u st b e l ow the b o dy cu t i c l e. P reanal r é g i on w i t h 7-9 pa i rs of la rge c a u d al pap i l lae in t w o

s u b v e n t r al r o ws ; the th ree pai rs c losest to the anus are c lose t o g e t h er whe reas the o t h er

pap i l l ae are m o re w i d e ly s p a c e d. Sp icu les p r o m i n e n t, 1.4-2.0 m m i n l eng th. Shaft of

sp icu les s lender, w i t h t u b u l ar cen t ral c o re a nd c u r v ed w ing - l i k e e x p a n s i on on the ven t ral

s ide. P r o x i m al end of sp icu le b l un t, d is tal e nd s h a r p ly p o i n t e d. G u b e r n a c u l um p r o m i n e n t,

113 -119 [xm l o n g, w i t h w i de p r o x i m al end a nd sha rp ly p o i n t ed d is tal end.

Female (5 s p é c i m e n s) : T o t al l eng th 6 .3 -8 .2 m m. L e n g th of oesophagus 8 8 2 -1 154 [ tm

( p h a r y n g e al p o r t i on 59 -72 [xm, pos te r i or p o r t i on of c o r p us 6 9 1 - 9 13 [xm, i s t hmus 34 -41 [xm,

a nd b u lb 109 -128 [xm). N e r ve r ing 4 0 0 - 4 84 [xm, e x c r e t o ry p o re 5 1 3 - 6 69 fxm, a nd v u l va

3 .5 -4 .5 m m f r om an te r ior e x t r e m i t y. V a g i na a p p r o x i m a t e ly 1.5 m m l o n g, s lender a nd

3, 7

— 710 —

m u s c u l ar t h r o u g h o ut its l eng th, d i r ec ted an te r i o r ly in first th i rd a nd t h en flexed to pos te r i o r.

Uteri o p p o s e d, o v a ry of p o s t e r i or u té rus l o c a t ed an te r ior to v u l v a, o v a ry of an te r ior u térus

l o c a t ed pos te r i or to v u l v a. E g gs o v a l, th in -she l led, 62 -72 u.m l o ng a nd 35 -45 p w i de (based

on 5 s p é c i m e n s ). La té ral a lae e x t e n d i ng f r om m i d - r e g i on of ta il to l e vel of n e r ve r ing.

Ta il 2 0 9 - 2 41 fxm l o n g, c o n i c a l, s h a r p ly p o i n t e d.

SPÉCIMENS EXAMINE D : ( 1) Z M B 1 0 27 (worms col lected by SCHNEIDER ( 1 8 6 6) f rom R. tempo-raria of Germany). ( 2) C IH 4 5 67 (R. temporaria, Eng land). ( 3) C IH 5 9 3 / 29 (B. bufo, L o n d on Z o o ). ( 4) Frandsen Personal Col lect ion B bu 2 8 (B. bufo, Denmark ). ( 5) C IH 8 0 5 / 30 (O. apodus, L o n d on Z o o ). ( 6) B M 1 9 2 3 . 8 . 2 8 . 8 7 - 91 (A. fragilis, S. atra, Eu rope). ( 7) BM 1 9 2 3 . 1 2 . 1 9 . 8 2 - 91 (S. maculosa, Europe). ( 8) BM 1 9 6 4 . 1 6 0 1 - 1 6 06 [B. bufo, Br i ta in). ( 9) M N H N 7 K A (S. maculosa, Corsica). ( 1 0) M N H N 4 18 NF (R. dalmatina, France).

FIG . 1. — Oxysomatium brevicaudatum (Zeder, 1800) Railliet & Henry , 1916. A , B, C, anterior extremity , latéral , apical and dorsal view ; D, idem, optical section through lips ; E, idem, section through base of lips ; F, idem, section through anterior end of oesophagus ; G, anterior end of maie, latéral view.

— 7 1 1 —

FIG . 2. — Oxysomatium brevicaudatum (Zeder, 1800) Railliet & Henry , 1 9 1 6. A , B, caudal end of maie, ventral and latéral view ; C, proximal end of spicule, latéral view ; D, anterior li p of anus of maie, ventral view ; E, vagina, latéral view ; F, distal end of spicule, latéral view ; G, tail of female, latéral view ; H , gubernaculum, dorsal view ; I , shaft of spicule, transverse section.

— 712 —

[• = O. brevicaudatum (Zeder, 1800) ; • = O. caucasicum (Sharpilo, 1974) n. comb. ; ̂ = O. dollfusi n. sp. j.

HOSTS : Rana arvalis, R. dalmatina, R. esculenta, R. graeca, R. macronemis, R. ridibunda, Hyla arborea, Pelobates fuscus, Alytes obstetricans, Salamandra salamandra (= S. maculosa), S. atra (new host record), Triturus alpestris, T. cristatus, T. vulgaris, Bufo bufo, B. regularis, B. viridis, Bombina bombina, Natrix natrix, Anguis fragilis, Ophisaurus apodus (new host record).

DISCUSSION

Z E D E R ( 1800) d e s c r i b ed a c o s m o c e r c o i d, Fusaria brevicaudata, f r om W e s t e rn E u r o p e an

a m p h i b i a n s. Th is spec ies w as redesc r i bed by SCHNEIDE R ( 1866) a nd p l a c ed in a n ew

genus, Oxysoma, w i t h t w o o t h er spec ies. A t y pe spec ies w as n ot des igna ted. STILE S

& HASSAL L ( 1905) sugges ted Oxysoma brevicaudata ( Z e d e r) be r e c o g n i z ed as t y pe spec ies

a nd s ince i t has p a ge p r i o r i ty in SCHNEIDER' S p u b l i c a t i o n, th is p r o p o s ai has been f o l l o w ed

i n la ter t a x o n o m ic s tud ies. RA ILL IE T & H E N R Y ( 1916a) c lea r ly i n d i c a t ed Oxysoma bre-

vicaudata ( Zede r) as t y pe spec ies of Oxysomatium and i t is é v i d e nt f r om th is p u b l i c a t i on

LOCALIT Y : A t ype local i ty was not specif ied but ZEDER worked in Germany and it is probable that his spécimens were f rom there. This species has been reported numerous t imes f rom many localit ies th roughout Western Europe and Britain and as far to the east as Chelyabinsk, U S SR (see fig. 3 ).

— 713 —

t hat the au tho rs b e l i e v ed t hat ZEDER' S a nd SCHNEIDER' S desc r i p t i ons we re of t he s a me

spec ies. H o w e v e r, i n a p u b l i c a t i on la ter t he s a me yea r, RAILL IE T & H E N R Y ( 19166)

i n d i c a t ed SCHNEIDER had e x a m i n ed a d i f férent spec ies f r om Z E D E R . T h ey p r o p o s ed

ZEDER' S spec ies be p l a c ed in Aplecta (= Aplectana), a nd the t y pe spec ies of Oxysomatium

was g i v en as the desc r i p t i on b y SCHNEIDER u n d er the n ew n a me Oxysomatium longespi-

culum (= Oxysoma brevicaudatum sensu Schne ide r, nec Z e d e r, nec Ra i l l i et & H e n r y, 1 9 1 6 a ).

U n f o r t u n a t e l y, SCHNEIDER' S d e s c r i p t i on is i n c o m p l è te by p résent s tanda rds a nd RAILL IE T

& H E N R Y d id n ot p r o v i de an a d é q u a te redesc r i p t i on.

SCHNEIDER' S o r ig inal s p é c i m e ns (2 çŁ a nd 12 $) h a ve b e en e x a m i n ed a nd c o m p a r ed

w i t h n u m e r o us c o s m o c e r c o i ds f r om v a r i o us a m p h i b i a ns a nd rept i les. B o th m a ie w o r ms

are ka th lan io ids of the genus Falcaustra L a n e, 1915 ( = Spironoura) s ince the c e p h a l ic

s t ruc tu res are t y p i c al of t hat genus, the œ s o p h a g e al i s t h m us is s w o l l en i n to a subsphae r i cal

shape w h i ch is cha rac te r i s t ic of m a ny ka th l an io i ds, a nd there is a s h a l l ow s u c k er on the

ven t ral c a u d al sur face 1 . T he fema le w o r ms are ail of t he S u b f a m i ly C o s m o c e r c i n ae and

t h ey b e l o ng to O. brevicaudatum ( Z e d e r ).

HARTWIC H (1975) a lso e x a m i n ed SCHNEIDER' S s p é c i m e ns a nd he d e s i g n a t ed t h em

s y n t y p es of O. longespiculum. H i s resdesc r i p t i on fa i led to d e m o n s t r a te t hat t he ma ies

and fema les are of d i f férent spec ies. T o c o n s e r ve the m u ch p u b l i s h ed n a me Oxysomatium

o ne fema le w o rm ( i l lus t ra ted by H A R T W I C H , 1975, fig. 8 0 c) is des i gna ted l e c t o t y pe of

O. longespiculum. Th is pe rm i ts O. longespiculum to be s y n o n y m i z ed w i t h O. brevicauda-

tum ( Z e d e r, 1800) Ba i l l i et & H e n r y, 1916a.

Oxysoma contortum L i n s t o w, 1906, is t rea ted here in as a s y n o n ym of O. brevicaudatum.

A l t h o u gh the o r ig inal desc r i p t i on of O. contortum is n ot de ta i led, t he p résence of c o n s p i-

c u o u s ly e l onga te sp icu les and the i l lus t ra t ion g i v en of t he sho rt m a ie tail is m o st s imi lar

t o O. brevicaudatum. A l so O. contortum w as r e p o r t ed f r om Bufo bufo, a c o m m on host

fo r O. brevicaudatum, in a l o c a l i ty ( B a l k a ns and G r e e c e) w h e re O. brevicaudatum has b e en

r e p o r t e d. I t is m o st un l i ke ly t hat t w o d i f fé rent spec ies w i t h d i s t i n c t i v e ly l o ng sp icu les

o c c ur in t he s a me h o st spec ies in the s a me l o c a l i t y.

K H A L I L (1932) r e p o r t ed Aplectana contorta in Bufo regularis 2 of L ibe r ia, A f r i ca. Th is

is far f r om o t h er l o c a l i ty repo r ts of th is spec ies a nd i t is l i ke l y t hat an e r ror of i den t i f i ca t i on

w as m a d e. S im i la r ly W A L T O N ( 1927) r e p o r t ed Oxysomatium longespiculum i n a s a l a m a n d er

f r o m N o r th A m e r i ca a nd th is is a d o u b t f ul i den t i f i ca t i on.

2. Oxysomat ium caucasicum (Sha rp i l o, 1974) n. c o m b.

Neoxysomatium caucasicum Sharpi lo, 1974.

O. caucasicum was d e s c r i b ed f r om Anguis fragilis in the Caucasus. S p é c i m e ns are n ot

ava i l ab le for s t u d y. Th is spec ies c a n n ot be d i s t i ngu i shed f r om O. brevicaudatum i n the m o r-

p h o l o gy of the an te r i or e x t r e m i t y, s h a pe of the m a ie a nd fema le tai l, n u m b er and d i s t r i bu t i on

1. Thčse maies probably belong to Falcaustra armenica (Massino, 1924) which has a similar maie caudal morphology and is the only Falcaustra sp. recorded fro m Western Europe. F. armenica is usually a parasite of freshwater turtle s and it m ay be rar e in anuran amphibians.

2. " Bufo regularis " of Afric a is a complex of several closely related species of Bufo.

— 714 —

of c a u d al pap i l l ae in m a i e s, s ize of the g u b e r n a c u l u m, a nd m o r p h o l o gy of the sp icu les.

A l s o 0. brevicaudatum has b e en r e p o r t ed f r om a f r og i n t he Caucasus a nd i t is a c o m m on

paras i te of A. fragilis i n wes te rn E u r o p e. T he r e p o r t ed d i f fé rence b e t w e en thèse spec ies

i n g u b e r n a c u l um shape w h en v i e w ed do rsa l ly seems to be s l ight. T he m a ie ta il i n b o th

spec ies is re la t i ve ly t h i ck in t he anal r é g i on a nd i n s p é c i m e ns of 0. brevicaudatum e x a m i n ed

i n t he p résent s t u dy a c lear do rsal v i ew of t he g u b e r n a c u l um w as o b t a i n ed o n ly by d issec-

t i o n of a w o r m. O. caucasicum a nd O. brevicaudatum di f fer s ign i f i can t ly o n ly in the l eng th

of the sp icu les. T h è se w e re r e c o r d ed as 3 8 0 - 4 00 u.m l o ng in O. caucasicum. I n c o m p a r i s on

sp icu le l e n g th in O. brevicaudatum is usua l ly r e c o r d ed as b e i ng at least 1.0 m m a nd th is

w as c o n f î r m ed in s p é c i m e ns e x a m i n ed in the p résent s t u d y. O n ly CHABAU D & CAMPANA -

R O U G E T ( 1955) h a ve o b s e r v ed m a ie O. brevicaudatum w i t h shor ter sp icu les ; t h ey d e s c r i b ed

a sma ll w o rm f r om Alytes obstetricans of s o u t h e rn F r a n ce w i t h sp icu les 750 fxm l o n g. T he

d i f fé rence in sp i cu le l e n g th b e t w e en O. caucasicum a nd O. brevicaudatum is never the less

so g reat t h at d é s i g n a t i on of thèse spec ies as s y n o n y m o us m u st awa it t he s t u dy of m o re

m a t e r i a l f r om s o u t h w e s t e rn Russ ia. O. caucasicum m ay be a s u b s p e c i es of O. brevicaudatum.

3. O x y s o m a t i um dol l fusi n. sp.

DESCRIPTIO N ( f ig . 4)

La té ral a lae n a r r o w. S o m a t ic pap i l l ae n ot n u m e r o u s. Oral o p e n i ng t r iangu la r, l ips

la rge. C e p h a l ic pap i l l ae i n c l u de s ix m i n u te lab ial pap i l l ae a nd s ix c e p h a l ic pap i l l ae of

w h i ch t he s u b m e d i an pa ir is m a r k e d ly smal l. A n t e r i or e x t r e m i ty of œ s o p h a g us w i t h

th ree t o o t h - l i ke p r o j e c t i o ns c o v e r ed w i t h t h i ck cu t i c l e.

Maie ( h o l o t y p e) : T o t al l e n g th 4 .8 m m. L e n g th of œ s o p h a g us 6 51 [xm ( p h a r y n g e al

p o r t i on 51 fxm, p o s t e r i or p o r t i on of c o r p us 4 63 fxm, i s t h m us 39 [xm, a nd b u lb 98 p ) .

N e r ve r ing 275 [xm a nd e x c r e t o ry p o re 4 02 fxm f r om an te r i or e x t r e m i t y. Ta il 137 u,m

l o n g, t ape r i ng r a p i d ly to l o ng p o i n t ed t e rm inal p o r t i o n. A n us o p e n i ng to e x t e r i or on

the a p ex of a m a r k ed swe l l i ng. La té ral a lae e x t e n d i ng f r om 5 0 0 - 6 00 [xm an te r ior to anus

t o m i d - r e g i on of œ s o p h a g u s. Caudal pap i l l ae m a r k e d ly la rger t h an s o m a t ic pap i l lae.

Pos te r i or ha lf of ta il w i t h t w o la rge s u b v e n t r al a nd t w o la rge s u b d o r s al pairs of pap i l l ae ;

s u b v e n t r al pai rs o f ten n ot a l i gned d i r ec t ly o p p o s i te e a c h o t h e r. A n t e r i or half of ta il and

anal r é g i on w i t h th ree pairs a nd o ne u n p a i r ed la rge pap i l l ae ; th ree pairs l o c a t ed s u b v e n-

t ra l l y a r o u nd base of swe l l i ng o n to w h i ch anus o p e n s, a nd u n p a i r ed pap i l la on an te r ior

l i p of anus. U n p a i r ed pap i l la w i t h cu t i cu l ar w ing - l i k e s u p p o r ts as o b s e r v ed i n t he t y pe

spec ies. P reanal r ég ion w i t h 8-9 pai rs of la rge pap i l l ae in t w o s u b v e n t r al r o ws ; t he 4 pa i rs

c losest to the anus are c lose t o g e t h er whe reas the o t h er pap i l l ae are m o re w i d e ly s p a c ed

a nd the pai rs are o f ten n ot a l i gned d i r ec t ly o p p o s i te e a c h o t h e r. Sp icu les p r o m i n e n t,

192 fxm l o n g, h o o k - s h a p ed in la téral v i e w, shaft d i v i d ed i n to r o b u st an te r ior th i rd and

m o re w e a k ly ch i t i n i zed pos te r i or pa rt s u p p o r t ed by a w i de m e m b r a n o us shea th. D is tal

e nd of sp icu les s h a r p ly p o i n t e d. G u b e r n a c u l um p r o m i n e n t, 78 [xm l o n g, w i t h w i de p r o x i m al

e nd a nd s h a r p ly p o i n t ed d is tal e n d.

Female ( a l l o t y p e) : T o t al l eng th 5.0 m m. L e n g th of œ s o p h a g us 780 fxm ( p h a r y n g e al

p o r t i on of c o r p us 58 jxm, pos te r i or p o r t i on of c o r p us 555 fxm, i s t h m us 55 [xm, b u lb 112 (xm).

FIG . 4 . — Oxysomatium dollfusi n. sp. A , reproductiv e System of female, latéral view  • B  caudal  end  m a u  ,  .  i n  r> 

E  cauda  extremity  latéral  dorsal  and  amical view  ; l idem,  section  through  base of Hp.  Gsect ion IhTouX  bu  ca  ™ W  S' 

latéral  v i č r ° U g T  " 77 "ff °?°?hagU?  !  S p i c u l e '  l a t e r a l  view  ;  J,  anterior  endP  o'f  maie  latéral  vfew  •  K  tail  K m a k ' latéral  view  ; L ,  caudal  end of maie,  latéral  view  ; M, gubernaculum,  dorsal  view.  '  female, 

— 716 —

N e r ve r ing 3 2 0 f im , e x c r e t o ry p o re 4 5 3 p , a nd v u l va 2 .8 m m f r om an te r ior e x t r e m i t y.

O v a ry of p o s t e r i or u té rus l o c a t ed an te r ior to v u l v a, t e rm inal ha lf of o v a ry of an te r ior u térus

l o c a t ed pos te r i or to v u l v a. E g gs o v a l, th in -she l led, 6 9 - 78 f i m l o ng a nd 4 0 - 45 f i m w i de (based

on five s p é c i m e n s ). La téral a lae e x t e n d i ng f r om an te r ior th i rd of ta il to m i d - r e g i on of oeso-

p h a g u s. Ta il 2 0 8 f i m l o n g, c o n i c a l, sha rp ly p o i n t e d, w i t h s l ight swe l l i ng near pos te r i or l i p

of anus.

Paratypes : D i m e n s i o ns of 5 m a ie a nd 4 f ema le p a r a t y p es are as f o l l o w s. Maies :

4 . 2 - 5 .1 m m l o ng ; o e s o p h a g us 6 2 2 - 7 24 f i m l o ng ( p h a r y n g e al p o r t i on 4 8 - 65 fzm, pos te r i or

p o r t i on of c o r p us 4 4 3 - 5 30 f im , i s t h m us 3 9 - 45 f im , b u lb 8 7 - 96 fini ) ; ne r ve r ing 2 8 7 - 3 15 f im ,

e x c r e t o ry po re 4 1 0 - 4 75 f i m f r om an te r ior e x t r e m i ty ; sp icu les 1 8 3 - 2 08 f im , g u h e r n a c u l um

7 5 - 86 f im , a nd ta il 1 3 4 - 1 56 fini l o n g. Fernales : 4 . 7 - 5 .0 m m l o ng ; o e s o p h a g us 7 3 8 - 7 67 \im

l o ng ( p h a r y n g e al p o r t i on 5 6 - 65 f im , pos te r i or p o r t i on of c o r p us 5 3 0 - 5 45 f im , i s t h m us 3 7-

6 0 f im , b u lb 1 0 5 - 1 12 f im ) ; ne r ve r ing 2 7 5 - 3 35 f im , e x c r e t o ry p o re 4 4 0 - 4 62 f im , a nd v u l va

2 . 5 - 2 .9 m m f r om an te r i or e x t r e m i ty ; ta il 1 8 6 - 2 20 f i m l o n g.

SPÉCIMENS EXAMINE D : ( 1) M N H N 1 0 90 BA ( type spécimens from Bufo mauritanicus). ( 2) M N H N 4 92 A (D. pictus).

LOCALIT Y : The t ype local i ty is Casablanca, Mo rocco. Ai l spécimens were f rom there.

HOSTS : Bufo mauritanicus, Discoglossus pictus.

DISCUSSION

O. dollfusi n. sp. c an be m o st eas i ly d i f îe ren t ia ted f r om the o t h er t w o spec ies in the

genus by sp icu le m o r p h o l o gy a nd leng th. In b o th O. caucasicum and O. brevicaudatum

the sp icu les are re l a t i ve ly l o ng ( > 3 5 0 f im ) w h e r e as in O. dollfusi t h ey are less t h an 2 2 5 fini

i n l eng th. T he sp i cu le shaft i n O. dollfusi f o r ms a r o b u st an te r ior p o r t i on a nd a less h e a v i ly

ch i t i n i zed pos te r i or p o r t i on w h i ch is s u r r o u n d ed by a w i de t ransparent m e m b r a n e. In

the o t h er t w o spec ies t he shaft of t he sp icu les is u n i f o rm in a p p e a r a n ce t h r o u g h o ut i ts

l e n g th a nd i t is g rea t ly e l o n g a t e d. T he m e m b r a n o us shea th o b s e r v ed a r o u nd t he pos te r i or

t w o - t h i r ds of the shaft i n O. dollfusi su r rounds a l m o st t he ent i re l e n g th of the shaft i n

O. brevicaudatum a nd O. caucasicum. F ina l l y, the sp icu les in O. dollfusi are b e nt i n to a

charac te r i s t ic h o ok shape in la téral v i ew whe reas t h ey are s l i gh t ly c u r v ed or va r i ab le in

shape i n t he o t h er t w o spec ies.

O T H E R SPECIES ASSIGNED TO Oxysomatium

A n u m b er of spec ies d e s c r i b ed o r i g ina l ly u n d er t he gene r ic n a me Oxysomatium we re

s u b s e q u e n t ly t rans fer red t o o t h er gênera i .e. Aplectana chamaeleonis (Bay l i s, 1 9 2 9) T ra-

vassos, 1 9 31 ; Aplectana hylambatis ( B a y l i s, 1 9 2 7) T r a v a s s o s, 1 9 31 ; Aplectana bonariensis

(Gu t ie r rez, 1 9 4 5) L e nt & F re i tas, 1 9 48 ; Aplectana mexicana (Caba l l e ro, 1 9 3 3) Ba l les te ros-

M â r q u e z, 1 9 45 ; Falcaustra inglisi ( A n d e r s o n, 1 9 6 4) B a k e r, 1 9 8 0. T he p résent s t u dy

c o n f i r ms thèse c h a n g e s. Oxysomatium ranae W a l t o n, 1 9 4 1, a nd Oxysomatium georgianum

R e i b e r, B y r d & Parke r, 1 9 4 0, b e l o ng in Aplectana as wi l l be d i scussed in a separa te pub l i-

c a t i o n. S im i la r l y, Oxysomatium srinagarensis F o t e d a r, 1 9 60 ; Oxysomatium anurae B is-

— 717 —

was & C h a t u r v e d i, 1963 ; Oxysomatium stomatici B i s w as & C h a t u r v e d i, 1963 ; Oxysomatium

brevispiculum Y u e n, 1965 ; Neoxysomatium longicaudatum A l i & I l yas, 1969 ; Oxysomatium

punctatum W a l t o n, 1933 ; Oxysomatium minulum R a s h e e d, 1 9 6 5, are ail s h o wn to be s y n o-

n y m o us w i t h v a r i o us Aplectana s p p.

T he or ig inal desc r i p t i on of Oxysomatium waltoni Sk r jab in, S c h i k h o b a l o va & M o z g o-

v o i , 1951 [ = Aplectana mexicana W a l t o n, 1940, p r e o c c u p i ed ; = Aplectana waltoni (Skr ja-

b in, S c h i k h o b a l o va & M o z g o v o i, 1951) Sk r jab in, S c h i k h o b a l o va & L a g o d o v s k a y a, 1961]

is i n a d é q u a te a nd fema les are n ot k n o w n. Th is spec ies is left incertae sedis.

T he or ig inal d e s c r i p t i on of Oxysomatium dogieli Sk r jab in, 1916 | = Oxysoma dogieli

Skr jab in, 1916, lapsus calami ; = Aplectana dogieli (Sk r j ab in, 1916) Y o r k e & M a p l e s t o n e,

1926] l acks déta i ls a nd the h o st ( f r om East A f r i ca) was i den t i f i ed o n ly to the F a m i ly B u f o-

n idae. T y pe s p é c i m e ns are n ot ava i l ab le for s t u d y. Ma ie w o r ms are c lea r ly c o s m o c e r-

c o i ds w h i ch b e l o ng to Aplectana, Oxysomatium, or Raillietnema. T h ey are s im i lar t o a nd

m ay be c o n s p e c i f ic w i t h Aplectana hylarnbatis (Bay l i s) or A. chamaeleonis ( B a y l i s ). SKRJA­

BI N s t u d i ed o n ly o ne i m m a t u re fema le w o rm w h i ch h ad a ta il w h i ch is unusua l ly short

and b l u nt for a m e m b er of t he C o s m o c e r c i n a e. T he r e p r o d u c t i ve Sys tem w as n ot descr i-

b e d. S ince the o r ig inal d e s c r i p t i o n, O. dogieli has b e en r e c o r d ed o n ly o n ce f r om K e n ya

(SCHMID T & CANARIS , 1 9 6 8 ). Thèse s p é c i m e ns h a ve b e en e x a m i n ed ( U S NM 6 3 1 2 3) and

t h ey b e l o ng to A. chamaeleonis. O. dogieli is des i gna ted a species dubia.

T he t y pe s p é c i m e ns of Oxysomatium tibetanum B a y l i s, 1927 [ = Aplectana tibetanum

(Bay l i s, 1927) T r a v a s s o s, 1931 (2 S on a p e r m a n e nt s l ide, B M 1 9 2 3 . 8 . 2 8 . 9 2 )] are p o o r ly p re-

se rved. H o w e v e r, t he n u m e r o us p reanal pap i l l ae are rose t tes a nd the spec ies b e l o n gs in

the genus Cosmocercoides. C. tibetanum (Bay l i s, 1927) n. c o m b. s h o u ld be r e e x a m i n ed a nd

c o m p a r ed w i t h o t h er Cosmocercoides s p p. w h en we ll f i xed s p é c i m e ns b e c o me ava i l ab le.

T he females of Oxysomatium baylisi W a l t o n, 1923 [ = Aplectana baylisi ( W a l t o n,

1933) L ô p e z - N e y r a, 1 9 4 7 ], are re l a t i ve ly sma ll (2 .2 m m l o n g, w i d th at v u l va 175 fxm),

and the eggs are la rge (120 u.m l o n g ). S ince c a u d al pap i l l ae in ma ies are s imp le in s t ruc tu re,

the spec ies b e l o n gs i n the genus Raillietnema a nd i t is here in des i gna ted R. baylisi ( W a l t o n,

1933) n. c o m b.

O ne t y pe ma ie ( U S NM 9 3 8 2) of Oxysomatium. georgianum R e i b e r, B y r d & Parke r, 1940,

has b e en e x a m i n e d. Th is spec ies is s y n o n y m o us w i t h Cosmocercoides dukae ( H o l l , 1928 ).

A n u m b er of spec ies o r i g ina l ly ass igned to Aplectana or s y n o n y ms of th is genus h a ve

b e en at s o me t i me t rans fer red to Oxysomatium. T he p résent s tud ies do n ot s u p p o rt a ny

of thèse t a x o n o m ic c h a n g e s.

Acknowledgement

This study was supported by a N A T O Postdoctoral Fel lowship f rom the Natural Sciences

and Engineer ing Council of Canada.

B E F E B E N C ES

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BAYLIS , H . A. , 1927. — On two new species of Oxysomatium (Nematoda), wi th some remarks on the genus. Ann. Mag. nat. Hist., 9th Ser., 19 : 279-286.

— 718 —

CHABAUD , A . G., 1978. — C IH Keys to the nematode parasites of vertebrates. N o. 6. Keys to gênera of the superfamil ies Cosmocerco idea, Seuratoidea, Heterakoidea and Subuluro idea, 71 p.

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Manuscrit déposé le 24 janvier 1980.