JapaneseJapaneseSociety Society ofSystematicof Systematic Zoology

Zool., No. 37:1-19. 25, 1988. PToc. .Iapn. Soc. syst. June

Trematodes of the Genera Coitocaecum, Dimerosacc"s and Opecoelus (Opecoelidae: Opecoelinae) from Freshwater Fishes of Japan

Takeshi SHIMAZU

Synopsis

SmMAzu, T. 1988 Trematodes of the genera Coitocaecum, Dim.erosaccus and Opecoelus (Opeeoelidae: Opecoelinae) irom freshwater fishes of Japan. Proc. Japn. Soc. "yst. Zool., Tokuo, No. 37: 1-19. Three species of three trematode genera (Opeeeelidae: Opecoelinae) are reported from freshwater fishes of ,Japan: (Joitocaectt7n plagie7'ch,is OzAKI, 1926; Dimerosacczts oneerhynehi (EGuciTr, 1931) SHIMAzu, 1980; and a new speeies Opecoel?ts ?.tkigori. Diagnoses of the family, subfarnily and genera are given. Each specties is deseribecl and illusti'ated, and its systemati[: position is diseussed. Opecot.lits ?{kigeri lrom Chaenogobins aimttla7'is (the freshwater and rniddle- reaehes types) (Gobiidae) of sauthern Hokkaido most elosely resembles O. 77tutzif YAMAGuTi, 1940, and O. va･?n'abilis CRiBB, 1985, in morphology, but differs from the former in more posteriorly leeated testes and a much shorter external seminal vesiele, and from the latter in a larger body size, longer digitiform appendages of the ventral sucker, a shorter external seminal vesiele and smal]er eggs. This trematode is likely to be a freshwater speeies.

This is the third report on the trematodes of the Japanese freshwater fishes. It deals with three species of the genera, Coitocaec?.tm NicoLL, 1915, Dimerosacctts SHIMAzu, 1980, and Opecoel･zts OzAKI, 1925 (Opeeo-- elidae; Opecoelinae). For the materials and methods, the first report (SHJMAzu, 1988) is to be referred.

Family Opecoelidae OzAKI, 1925

Opeeoelidae OzAKi, 1925, p. 53 (type genus, Opecoelus OzAKi, 1925). Coitoeaeeidae OzAKT, 1929, p. 76 (type genus, Coitocaec"･m NicoLL, 1915). Podocotylidae DoLLFus, 1960, pp.101-102 (type genus, Podocotyle DuJARDIN, 1845).

Diagnosis. Trematoda: Opeeoeloidea. Body elongate or oval,

' fiattened or cylindrical, aspinose, nonoculate. Oral sucker subterminal. Prepharynx short or practieally absent. Pharynx present. Esophagus variable in length. Intestines }ong, terminating blindly, opening poste- riorly through separate ani, fusing with exeretory vesicle to form a

uroproet, er uniting with eaeh other to form a eycloeoel or to open

through a single ventral anus. Ventral sucker in anterior half of body,

NII-Electronic Library Service JapaneseJapaneseSociety Society ofSystematicof Systematic Zoology

2 T. Shimazu

sessile or pedunculate, with or without papilliform or tentacular append- ages on anterior and posterior lip margins. Testes usually t･wo, rarely three to ten (usually nine), opposite, oblique or tandem, in hindbody. Cirrus pouch usual}y present, rarely rudimentary or absent; when large and rather thin-walled, ineluding

seminal vesicle, prostatic complex and cirrus, but external seminal vesicle

absent; when small, usually museular and thiek-walled, containing short internal seminal vesicle, prostatic eomplex and cirrus, and external seminal vesiele ]arge and enclosed or not by a thin membranous poueh. Genital atrium small. Genital pore anterior to ventral sucker, ventral, usually sinistro-submedian or -submarginal, rarely median, occasionally with

aceessory sucker. Ovary pretestieular, median or submedian. Ootype- complex and LAuRER's eanal pi'eovarian. Seminal reeeptacle present or absent. Uterus usually preovarian or pretesticular, rarely extending into inter- or post-testicular region; metraterm present. Eggs operculate, filamented or not, usually not embryonated or rarely fully embryonated,

when laid. Vitellaria fo!lieular, circumeecal, continuous or interrupted, usually reaching posterior end of body and confluent behind testes, valiable in anterior extent. Excretory vesicle tubular, epithelia], variable in extent, with posteroterminal or almost dorsal exeretory pore. Adults parasitic in digestive tract of marine and freshwater teleosts. Miracidia nonoeulate, with one pair of flame eells; epidermal eell

tormula reportedly 6, 7, 4, 2, or 6, 6, 4, 2. Cotylomierocercous cercariae developing in sporocysts in prosobraneh snails ; fiame eell formula 2 [(2+ 2)+(2+2)]=16. Metacercariae encysting in aquatie arthropods, occa- sionally progenetic. Type genus: Opecoel･ics OzAKI, 1925. Discussion. This diagnosis has been based mainly on OzAKi (1925, 1928), YAMAGuTI (1971), GIBsoN (1976), ScHELL (1976), BRAY (1979), GIBsoN and BRAy (1982), and CRIBB (1985). The family Noto- porida'e YAMAGuTI, 1938 (type genus, Notoportts YAMAGuT'I, 1938) (YAMAGUTI, 1938, p. 55) is very closely related to the Opeeoelidae in general morphology in spite of the dorsal position of the genital pore and the absence of the cirrus. YAMAGuTI (1938) mentioned and figured the presence of the eyespots in N. ti"achzo"i YAMAGuTI, 1938 [:=Neono- toporus traehztri (YAMAGuTI, 1938) SRivAsTAvA, 1942], but it has been denied by Si{IMAzu (1981), who reported an eneysted metacercaria considered this species from a euphausiid crustacean, E'ttpha'Msia sim711is. YAMAGuTI (1939) described the excretory system in the adult stage of "the N. t7:achuri as collecting vessel...divides...into two tubules (an anterior and a posterior>, each of which bifurcates two times" and gave

NII-Electronic Library Service JapaneseJapaneseSociety Society ofSystematicof Systematic Zoology

3 Opeeoeline Trematodes of Japanese Freshwater Fishes

"(2+2+2+2) the fiame cell formula as × 2=16." The meaning of the above-quoted deseription is ambiguous, but it is apparent that the anterior and posterior eolleeting tubules have four fiame cells each. Aceordingly, it is possible that the flame cells formula is 2[(2+2)+(2+2)]=:16. The Notoporidae might well be a synonym of the Opecoelidae. SRIvAsTAvA (1942, p.131) reduced the Notoporidae to the rank of a subfamily Notoporinae and assigned it to the family Alloereadiidae STossicH, 1903. MANTER (1947) plaeed it in the Opecoelidae. He also eonsidered that the family Sphincterostomatidae YAMAGuTI, 1937 (type genus, Sphincter- osto7}ta YAMAGuTI, 1937) (YAMAGUTI, 1937, p. 6), is a synonym of the Opecoelidae. I feel some hesitation in accepting this synonymy on account of the presenee of a very thick tegument, a powerful sphincter at the opening' of the oral sucker, a median and just postbifurcal genital pore and a postovarian ootype-complex in S. b･i'aizeh･iostegi YAMAGuTI, 1937, the type species (YAMAGuTI, 1937).

Subfamily Opecoelinae STuNKARD, 1931 epece:linae STvNKARD, 1931, p. 724 (type genus, Opeeoekts OzAm, 1925). Coit,o(:aecinae PocHE, 1926, p. 163 (type genus, Coitocaec?{･m NiceLL, 1915).

Dia･gnos･is. Opecoelidae. Intestines ending blindly, opening through one or two ani, or fusing with exeretory vesicle to form a uroproct or with each other to form a eyclocoel. Ventral sueker sometimes with marginal appendages. Testes two. Cirrus poueh small, muscular alld thick-walled, or rudimentary or absent. External seminal vesicle enclosed by thin pouch or not. Genital pore prebifurcal; accessory s'ucker sometimes present. Seminal receptacle absent; proximal eoils of uterus forming a uterine seminal receptacle. Eggs without filaments. Intestinal parasites of marine and freshwater fishes. Miracidia nonoeulate, with one pair of flarne cells; epidermal cell formula reportedly 6, 7, 4, 2, or 6, 6, 4, 2. Cotylomicroeercous cercariae produeed in sporocysts in prosobTaneh snai!s; flarne cell formula 2 [(2+ 2)+ (2+2)]=16. Meteeercariae encysting in aquaric arthropods, some- times progenetie. Type genus: OpecoeZzts OzAKI, 1925. I)?Isc･z(ssion. This diagnosis of the subfamily has been based mainly on STuNKARD (1931), YAMAGUTI (1971), GIBSON (1976) and GIBsoN and BRAy (1982).

Genus Coitoeaecum NICOLL, 1915

Coitoca.ecu-n NIcoLL, 1915, p.25, originally spelled Coitocoecuwt (type speeies, Co･ito- caecunz gymnophalZtem NIcOLL, 1915).

NII-Electronic Library Service JapaneseJapaneseSociety Society ofSystematicof Systematic Zoology

4 T. Shimazu

Ozak-ia WiSNiEwsKi, 1933: p. S4 (type species, Coi,tocaecum plagiorehis OzAKT, 1926); ' WIsNIEvvsKi, 1934, pp. 35, 38, table 1, Pseuaocoitocaee'uon. BiLQEEs, 1972, p.21 (type speeies, Pscudocoitoeaec-um thrissoclesis BILL,QEEs, 1972). Pav'a.da.ct'ulostomu･m ZIIuKov, 1972, p.347 (type speeies, Pa.7"adact?vlostomum i･izdiczept ZHuKov, 1972).

Diagnosis. Opecoelidae: Opecoelinae. Cycloeoel present. Ventral sueker without marginal appendages. Cirrus poueh small, sometimes muscular and thick-walled; external seminal vesicle lying free in paran- chyma. Aecessory sucker absent. Vitellaria sometimes entering fore- body. Intestinal parasites of marine and freshwater fishes. Miracidia nonoculate, with one pair of flame cells. Cotylomiero- cer"cous cercariae developing in sporoeysts in prosobraneh snails; flame

ce]1 formula 2[(2+2)+(2+2)]=16. Metacercariae encysting in am- phipods and shrimps. Type species: Co･itocaeczt.]'n. gy7nv'zophallztm NIcoLL, 1915. Dilsc?.{ssion. In ereeting this genus for a new species, C. gy･mno- ph･alltt77z･, NIcoLL (1915) described the cirrus poueh as absent in this species. OzAKi (1926, 1929) observed the presence of a small museular cirrus pouch eontaining the internal seminal vesiele, prostatic eomplex and ejaculatory duet in his new species, C. plagio7och･is and four others. 'WIsNIEwSKI (1933, 1934) proposed a new genus 02a･kia to aecommodate･ C. plagiorehis and the four other speeies and separated Coitoeaeczem and Ozaicia by the anatomical structure of the eirrus pouch. However, it is clear that this proposal was brought about by a kind of misinterpretation (CRowcRoFT, 1951) of the male terminal genitalia shown in NIcoLL's original figure for C. gym)zophallzLm. CRowcRoFT (1951) proved the presence of a small membranous cirrus pouch enclosing a short terminal portion of the male duet and of a large seminal vesicle being almost entirely external in NIcoLL's, probably original specirnen of C. gy7nno- pltalltt"z, and took Coitocaeczon and Ozalsia as generically identical.

According to BRAy (1987), the type speeies of Pset{docoitocaecumBILQEEs,, 1972, and that of Pa,i'a･clactylostomzem ZHuKov, 1972, are the same species, and these two genera are synonymous with Coitoca･ee'tL"z. MEuRA (1966) reduced Nicolla (originally spelled IVieoll?la) WISNIEwsKI, 1933, to synonymy with Coitocaectt7n, but the former as defined by WISNIEwSKI (1934) is distinct from the Iatter in having a short oveid cirrus poueh containing the whole rnale terminal duct and the genital pore being median and postbifureal. The above generic diagnosis has been based mainly on NicoLL (1915), OzAm (1929), CRowcRoFT (1951) and BRAy (1987).

NII-Electronic Library Service JapaneseJapaneseSociety Society ofSystematicof Systematic Zoology

Opeeoe]ine Trematedes of Japanese Freshwatcr' Fishes 5

Cbitocaecum plagiorchis OzAKI, 1926

Coitocaecztm plagiorchis OzAKI, 1926, pp. 125-128, no figure. Co･i,toceecu"t plag'i.o･rchis OzAKr, 1929, pp. 77-82, figs. 1-3. Ozak;ia･ plagioT'ch'is : WISNIEwsKI, 1933, p. 34; WISNmwsK, 1934, p. 38, table 2,

Mate7'ial exam･ined. 1) Lot 1. Four (2 immature and 2 gravid) whole-mounts (MPM Coll. No. 22585) of C. plagto7-chis of YAMAGuTI (1934) from the intestine of Mogurnda obscztra [=Odontobzttis obsczcra]

Kyoto, on June 2 and 5 and July 10, 1936. 3) Lot. 3. Three gravid-whole mounts (MPM Coll. No. 22292) of C. plagio?ochis of YAMAGuTI (1942) from the intestine of the same species fish (experimental infection). 4) Lot 4. Two gravid whole--mounts (MPM Coll. No. 22587) of C. plagio7"chis of YAMAGuTI (1939) from the intestine of Chaenogobi･tts ,annula7"is ?{rotaenia [=::C. an}zzela7'is] (Gobiidae) from Lake Biwa, Shiga Prefecture, on December 3, 1938. 5) Lot 5. 0ne immature whole-mount (NSMT-Pl 3105) eolleeted by NAGAsAwA from the intestine of the same speeies fish from this same lake (Ono'e) on February 4, 1980. 6) Lot 6. 0ne immature whole-mount (NSMT-Pl 3106) found in the intestine of the same species fish from Ono'e on June 6, 1980. 7) Lot 7. Two immature whole-mounts (NSMT-Pl 3104) found in ･isoxa the intestine of Chaenogobizts from Ono'e on June 6, 1980. 8) Lot 8. Three (1 immature and 2 gravid) unidentified and un- published whole-mount (MPM Coll. No. 30013) in OzAKI's colleetion "Small from Goro" [==C. isaxa?] fTom the same lake (other data not given). 9) Lot 9. Four (1 immature and 3 gravid) whole-mounts (MPM Coll. No. 22553) of C. plengio7'chis of YAMAGuTI (1934) from the intestine of B7'yttostcs kawameba･7"i [=Co･reope･rca ltatvameba7'i] (Percichthyidae) from the Asago River, Hyogo Prefecture, on JanuaTy 7 and April 7, 1932. 10) Lot 10. Two irnmature whole-mounts (MPM Col}. Ne. 22586) of C. plagioi"chis of YAMAGuTI (1939) from the intestine of Pelteobag?'us }zztdiceps (Bagridae) from Lake Biwa on December 7, 1938.

NII-Electronic Library Service JapaneseJapaneseSociety Society ofSystematicof Systematic Zoology

6 T. Shimazu

Figs. 1-3, Coi･toc;aecu･m ptagiorchis OzAKT, 1926, YAMAGUTI's unpublished gravid 1. Entire worm, ventral specimens from Odon･tobutis obscu･ra. from Kyoto, view. 2. Terminal genitalia, ventral view. 9. 0varian eomplex, dorsal view. terminal Fig. 4. C. plagiorchis, immature speeimen from Chaenogobius annul･aris, genitalia, showing a thin membrane surrounding the distal part of the external seminal vesiele, ventral view. (Scale bars: O.5mm in Fig, 1; O,1mm in Figs. 2-4).

collected by 11) Lot 11. 0ne gravid whole-mount (NSMT-Pl 3102) NAGAsAWA from the intestine of the same speeies fish from Ono'e on

November ll, 1980.

collected 12) Iuot 12. One immature whole-mount (NSMT-Pl 3103) by him from the intestine of Cott?ts ohmiensils (Cottidae) from Ono'e on

February 4, 1980. Desc}'ipt,ion. 1) For lots 1 and 9, 4 and 10, and 3, see YAMAGuTI (1934, 1939, 1942), respeetively. YAMAGUTI (1934) described the ex- cretory vesicle as Y-shaped, but this organ is distinetly I-shaped as ' deseribed by OzAKi (1926, 1929). In one specimen of lot 3, the uterus with many eggs in it･ descended along the left side of the testes as far as the posterior border of the posterior testis.

NII-Electronic Library Service JapaneseJapaneseSociety Society ofSystematicof Systematic Zoology

Opecoeline Trematodes of Japanese FTeshwater Fishes 7

2) Based on lots 2, 5-8 alld 11-12 ; 14 gravid whole-mounts measured (Figs. 1-3). Body oblong or laneeolate-oblong, slightly wider in hindbody than in forebody, e.94-1.60 by O.44-O.78; forebody 40-50% of total body length. Oral sueker anteroterminal, O.12-O.20 by O.13-O.20. Prepharynx very short. Pharynx globular or elliptical, O.08-O.11 in diameter. Esophagus O.05-O.12 long, bifurcating midway between pharynx and ventral sucker;cyclocoel reaching to near posterior end of body. Ventral

sueker sessile, O.20-O.27 by O.20-O.31; sucker width ratio 1: 1.44-1.72. Testes entire, contiguous, oblique, lying eneireled by cyclocoel, O.12- O.23 by O.16-O.31. Cirrus poueh club-shaped, in front of intestine or slightly overlapping it posteriorly, O.12-O.19 by O.04-O.06. Internal seminal vesicle small, swelling, containing sperms. Pars prostatica

usually ovate. Cirrus short, nonspinous. External seminal vesicle sinuous, anterior to ventral sucker or extending to mid!evel or rarely to posterior border of ventral sucker, surrounded by dispersed gland cells (prostatic?). Genital atrium small. Genital pore submedian, to left of pharynx. Ovary globular, anterodextral to lateral to anterier testis, O.08-O.14 in diameter.

Oviduet usually originated from right side of ovary. Ootype located anterosinistral to ovary; MEHLIs' gland eompactly massed around ootype. LAuRER's eanal lying usually anterior to ootype. Uterus pre-ovarian or -testieular, intercecal; metraterm shorter than cirrus pouch. Eggs rather many, 56-68 by 34-38 rtm in balsam. Vitelline follicles entering forebody usually to midesophageal level or sometimes to pharyngeal level, separated anteriorly. Exeretory vesicle extending to anterior border of

anterior testis. In the immature speeimen of lot 7, a thin membrane, whieh was anteriorly eonnected continuously to the thick-walled cirrus pouch and indiseernible posteriorly, appeared to enelose the distalmost portion of the external seminal vesicle and a small number of gland cells (Fig. 4). Disc･z･tssion. OzAKI (1926, 1929) first described this speeies from the stomach and intestine of Mogternda obsc2tra [=Odontobz{.tis o.] from Saijo, IIiroshima Prefeeture. He deposited the holotype (No. P. 235) in

the colleetion of the Zoological Institute, Science Faculty, Tokyo Imperial University, but it is believed to have already been lost. YAMAGuTI (1934) briefly deseribed the speeies (lots 1 and 9) from the same speeies fish from Lake Ogura, Shiga Prefecture, and from Bryttosus icawa?nebar'i [==Co7'eopei'ca･ k.] from the Asago River, Hyogo Prefeeture. He (1939) reported it (lots 4 and 10) from Chaenogob'i?ts amiula'ri$ zerotaenia [ == C. a･nn7.tlaris] and Pelteobago"zts n･z{cliceps from Lake Biwa, Shiga Prefecture. He (1942) obtained it from Misg2trnus angzeillicaudat･zt･s (Cobitidae) from Nishinomiya, Hyogo Prefecture, and from Gob-i2ts simitis [=Rhino-

NII-Electronic Library Service JapaneseJapaneseSociety Society ofSystematicof Systematic Zoology

8 T. Shimazu

gobius brzennezLs] (Gobiidae) from Shirakawa, Kyeto, but his specimens have not･ yet been located. A thin membrane appeared to enclose the distalmost portion of the external seminal vesicle and a small number of giand eells (pros- tatie?) in the immature specimen. The presenee of a similar membrane was noted by BRAy (1987) in the adult stage of an opecoeline opecoelid, Dactylostomieooz griX7ithsi BRAy. This feature suggests that the mem- brane is the vestige of the membranous pouch which has originally been formed as a thin-walled proximal portion of the eirrus pouch during premature stages of worms; and that a change in strueture of the eirrus pouch takes place in Co'itocaec2t"i･, with disappearance of the portion, from the type as seen in adults of Di･me?';osacc?ts and most presumably of Margolis･ia B"Ay (BRAy, 1987) to the type exhibited by adults of Coitoeaec2e7n and OpecoeZ2ts (see this paper) at some stage of develop- ment of worms, as observed in a Iepocreadiid, Pai'a･lepiaapedon hoplo- gnathi (YAMAGUTI, 1938) (SmMAzU and SHIMuRA, 1984). Sinee, as to C. plttsi,o7'chis, the male terminal genitalia are almost fully formed to the type of the adult stage in the metacercarial stage (KoMIyA and TAJiMi, 1943), the change may well eome in early stages of meta- cerearial development. Sueh a structural ehange in the course of development of worms would be of phylogenetie significanee in opecoelid trematodes. Further study is needed. The adult stage of C. ptagio7'ch'is has been reeorded not only from O. obsctt･la but also from Cha･enostobit{s a7znzela･ris, C. isaza (ineluding "Small Goro"), Coreope7ica icawamebari, Cottzts ohmiensis, Misgttrnt{s angz{･illicatedat7ts, Pelteobag7"zts nztd'iceps and Rhinogobitts b?'ztnnezts from the Kinki and Chugoku districts, Japan (OzAKI, 1926, 1929; YAMAGuTI, Mastacembelus ac2･tleatzts (Mastaeembelidae) from the vicinity of Shang- hai (KoMIyA and TAJIMI, 1943) and from Hubei Province (INsTITuTE OF HYDROBIoLOGY, HUBEI PROvlNcE, 1973).

The metaeerearial stage has been found encysted in a shrimp, Leander paztc･idens [==Pa･lae7non (P.) paucidens] (Palaemonidae) from [the Katsura River, Kyoto] (YAMAGuTI, 1942; 1 excysted worm, MPM Coll. No. 22292) ; and in another shrirnp, Caridina denticula- [=Neoea･iid･i?za d.] (Atyidae) from the environs of Tosu, Saga Prefecture (YAMAGuTi and NIslMuRA, 1944; 7 excysted worms, and 10 immature and 1 gravid worms recovered frorn Odontob･utis obscz{ra fed metacereariae experimentally, MPM Coll. No. 22293), from Katayama, Hiroshima Prefecture (OKABE and SHiBuE, 1952), and from Kururne, Fukuoka Prefecture (SHrBuE, 1953). In China, KoMIyA and TAJiMI (1943) described it from Mac7io- b･rachizmt nipponense (Palaemonidae). The eerearial stage is unknown.

NII-Electronic Library Service JapaneseJapaneseSociety Society ofSystematicof Systematic Zoology

Opeeoeline Trematodes of Japanese FTeshwater Fishes 9

Genus Dimerosaccus SHIMAZU, 1980 Dioneo'osaccus SHIMAzu, 1980, pp. 163-164 (type species, Allec7'eclizt'n･t oitcorhyeechi EGucHI, 1931).

Diagnos'is. Opecoelidae: Opecoelinae. Intestinal eeea terminating blindly. Ventral sucker without marginal appendages. Cirrus poueh small, muscular, thiek-walled; thin pouch enclosing exteTnal seminal vesicle and gland cells (prostati¢ ?). Aecessory sucker absent. Vitelline follicles may enter forebody, Excretory vesicle reaching to ovary; fiame eell formula 2 [(2+2) + (2+2)]=16. Type species: Alloeredi'um onco'rh･ynchi EGucHi, 1931.

Dimerosaceus oncorhynchi (EGUCHI, 1931) (Figs. 5-7)

Allocread･ittm eitcot'hynchi EGucHi, 1931, pp.20-22, no figure; EGucm, 1932, pp.24-28, figs. 1-6. Pla･giof)orz{s oncorhv7tchi: PETERs, 1957, p. 140. Dimerosaccus oncorhu'nch･i: SHIMAzu, 1980, pp, 164-166, tigs. 1-7.

Mate7"inl e:xamined. 1) Lot 1. Ten gravid whole-mounts (NSMT- Pl 2169-2172) of D. oncor]tynchi of SHIMAzu (1980) from the intestine of Oncorhynchics ?"hodz""zts f. mac7'ostomns [ =O. rhodu･nts] (Salmonidae) from the Nagara River at Gujohachiman, Gifu Prefecture, on September

12, 1975, January 20, 1977, and Mareh 31, 1979. 2) Lot 2. Fifty-four (36 gravid and 18 immature) whole-mounts (NSMT-PI 1945-1950 and 2168) of D. onco7"h･ynchi of SHIMAzu (1980) from the pyloric ceca and intestine of Salvelinzts leuco?naenis plievius [=-S. pluvizts] (Salmonidae) from the Samu River (a tributary to the Chikuma River) at Fujisawa, Iiyama, Nagano Prefecture, on September

16, 17 and 24, 1978, and Mareh 18, 1979. 3) Lot 3. 0ne gravid whole-mount (NSMT-PI 2173) of D. oneo- 7'hynchi of SHIMAzu (1980) from the intestine of the same species fish from the Hime River at Hakuba, Nagano Prefecture, on July 13, 1979. 4) Lot 4. Twelve (8 gravid and 4 immature) whole-mounts (MPM Coll. No. 19260) of D. oncorhynch･i of SHiMAzu (1980) from the intestine of O. masoze f. ishikawai･ [ =O. 7'nasozt] from the Horei River at Sanriku, Iwate Prefecture, on March 19, 1978. 5) Lot 5. Two gravid whole-mounts (NSMT-Pl 3094-3095) from the intestine of the same species fish from the Shokanbetsu River, at

Mashike, Hokkaido, on August 1 and 2, 1984.

NII-Electronic Library Service JapaneseJapaneseSociety Society ofSystematicZoologyof Systematic Zoology

10 T. Shirnazu

1

Figs. 5-7, Dimerosaccus oncorhynchi (EGucHi, 1931), gravid specimens from Onco- rhynchus masou from the Shokanbetsu River, Mashike, Hokkaide.-- -6. --- 5. Entire worm, ventral view. Termi'nal genitalia, ventral view. 7. 0varian eomplex, dorsal view. (Seale bars: O.5mm in Fig. 5; U.1mm in Figs. 6-7.)

6) Iiot 6. Two gravid whole-mounts (NSMT-Pl 3096-3097) from the intestine of S. Iez{coma･eni.s from the same locality on July 26 and

August 2, 1984. 7) Lot 7. Two gravid who]e-rnounts (NSMT-Pl 3098-3099) from the rectum (aecidental?) of Cott･zLs pollztx (Cottidae) from the same loeality on August 1, 1984. Desc7"i･pt?lovz. 1) For the morphology and measurements of lots 1-2 and 4, see SHIMAzu (1980). Re-examination of them has indieated that the metraterm is shorter than the eirrus pouch and possesses, around the orifiee, a sphincter with a creseent-shaped thickening between the

NII-Electronic Library Service JapaneseJapaneseSociety Society ofSystematicof Systematic Zoology

Opeeoeline Trematodes of Japanese Freshwater Fishes 11

cirrus and the metraterm; and, in one specirnen of lot 4, the vitellaria

reach to the intestinal bifurcation level. The speeimen of lot 3 is similar

to them in morphology. He noted and figured anomalous specimena bearing probably incompletely divided tests in lot 4. 2) Based on lots 5-7 (Figs. 5-7). Body lanceolate-oblong, some- times with truneate posterior end, 1.36-2.30 by 0.50-O.78; forebody 34- 44% of total body length. Oral sucker O.16-O.20 by O.16-O.21. Prepharynx

very short. Pharynx O.11-O.16 by O.11-O.15. Esophagus O.12-O.20 long. Ven'tral sucker sessile, postbifurcal, O.24-O.29 by O.26-O.32; sueker width ratio 1: 1.39-1.7L

Testes entire or slightly indented, in middle one-third of hindbody, O.11-O.27 by O.20-O.35. Cirrus pouch 0.08-O.13 by O.05-O.06; internal seminal vesiele very short; pars prostatica small; eirrus short; mem- branous pouch not extending posteriorly beyond midlevel of ventral sucker, O.16-O.30 long, ineluding undulating tubular external seminal vesiele and a large number of gland eells. Genital atrium small. Genital pore sinistrosubmedian at pharyngeal level. Ovary transversely reniform or triangu}ar (or weakly trilobed), O.09-O.16 by O.16-O.24. 0otype-complex anterior or anterolateral to ovary. LAuRER's canal opening dorsally to

ovary. Uterus preovarian, intercecal; metraterm well-developed, sherter than eirrus pouch; sphincter bearing a ereseent thickening. Eggs about 20, 58-64 by 34-38 /tm in balsam. Vitellaria extending anteriorly to midlevel of esophagus. Exeretory vesicle reaching to ovary. There was not seen a clear-cut boundary between the membranous pouch and the muscular eirrus poueh in some specimens (Fig. 6), suggesting that the anatomical structure is gradually transformed from membranous to muscular wall. Disczesston. EGucHI (1931, 1932) originally described this species as Allocreaditw?z oncorh･ynchi･ (Alloereadiidae) from the digestive traet of O. 7nacrosto･mz{s [ =O. 7'hoditr7.ts] from the Nagara River. (The exact locality was not speeified.) Re-examining one of EGucHI's specimens, PETERS (1957) tentatively transferred it to the genus Plagioporzts STAFFoRD, 1904 (Opeeoelidae). YAMAGuTI (1958, 1971), who also re- examined the syntype, retained it within the genus Alloci'eadi?cnz Looss, 1900, and stated that it should be referred to an opecoelid genus. SHIMAzu (1980) erected a new genus D･ime7"osacc2ts for it on account of the charaeteristic male terminal genitalia. EGucHI's original specimens could not be traced, and probably all of them have already been lost (SHIMAzu, 1980). The Honshu form (lots 1-4) and the Hokkaido form (Iots 5-7) agree well with eaeh other in every morphological feature except in the

NII-Electronic Library Service JapaneseJapaneseSociety Society ofSystematicof Systematic Zoology

12 . T. Shimazu

anterior distribution of the vitellaria. In the former, they end posterior to t･he bifurcal level; but in the latter, anterior to it. It seems that this difference is slight and of no speeifie importanee. The adult stage of the species has so far been recorded from Cotttts ･rhocltt7'?.Ls, pollz{x, Oncorhynch.z.{s masoze, O. Salvel･inus le･zeco7naenis and S. plu.vites only from the Hokkaido, Tohoku and Chubu districts, Japan (EGucHi, 1931, 1932; SHIMAzu, 1980; this paper). The life cycle is unknown.

Genus Opecoetus OZAKI, 1925

Opecocltts OzA-, 1925, pp.51-52 (type species, Opeeoeltts sphaerieus OzAKi, 1925, oTiginally spelled O. sphoericus). Opegaster OzAKI, 1928, p.17 (type species, Opeceelus o･vata OzAKi, 1928, originally spelled O. ovatus).

Diagnosis. Opecoelidae: Opecoelinae. Intestines uniting to open thTough a ventral eommon anus near posterior end of body. Ventral sucker bearing 3 (or rarely 5 or none) pairs of papilliform or digitiform marginal appendages. Cirrus pouch small, muscular, thick-walled ; external seminal vesicle lying free in parenchyma. Accessory sucker absent. Vitellaria extending' anterior]y to various levels, sometimes entering fore-

body. Excretory vesiele reaching to ovary; flame cell formula 2[(2+2)+

(2+2)]=16. Intestinal parasites of marine and freshwater fishes. Miraeidia with ciliated epidermal plates arranged in 4 tiers of 6, 6, 4, 2; flame eells two. Cotylomicrocercous eercariae produced in sporocysts in prosobranch snails; flame cell formula 2[(2+2)+(2+2)]=16. Metacercariae encysting in atyid, palaemonid and parastaeid crustaceans. Type species: Opecoelans sphae7'iczes OzAKI, 1925. D･?lscztssion. OzAKI (1925) erected this genus for new species, O. sphae7'Jicz{.s and O. Iobat2es. Later he (1928) ereated another new genus Opegaster for a new species, Opegaster ovata. Many species have since been described in both of these two genera. The closeness of the two genera and the considerab]e overlap of eharacters in some species have been the subjeet of wide comment (CRIBB, 1985). Discussing the dif- ferenees between them in the protrusion of the ventral sucker, the degree of development of the marginal appendages of the ventral sueker. the posterior extent of the seminai vesicle and the anterior extent of the vitellaria, CRIBB (1985) has made Opegaster a synonym of Opecoelus. I agree with him. Opecoel?,cs mzttz{･ YAMAGuTI, 1940, as well as Opecoelies va}iiabzllis CRIBB, 1985, and the present new species (see below) offers an example of an interrnedjate form between the two genera as defined

NII-Electronic Library Service JapaneseJapaneseSociety Society ofSystematicof Systematic Zoology

Opecoeline Trematodes of Japanese Freshwater Fishes 13

by OzAKI (1925, 1928). I have verified this by reexamining YAMAGuTI's (1940) type series of this species (MPM ColL No. 22135, 17 gravid whole-mounts). It is practically impossible to distinguish the two genera from each other. The above generic diagnosis has been based mainly on ･ OzAKI (1925, 1928) and CRIBB (1985).

Opecoelus ukigori sp. nov. (Figs. 8-13)

Mate･}"ia･l exa･mined. 1) Lot 1. Three gravid whole-mounts (NSMT- Pl 2933 and 3107) found in the intestine of Chaenogob?1?.t.s annztlar･is' (the middle-reaches type) (Gobiidae) from the Oono River at Oono, Hokkaido,

on August 20 and 23, 1984. 2) Lot 2. Eighteen gravid whole-mounts (NSMT-Pl 3108-3117) found in the intestine and reetum (accidental?) of the same speeies fish (the freshwater and middle-reaehes types) from the Tobetsu River at Kamiiso, Hokkaido, on August 26, 1984.

In June to August, 1984, this trematode was found in C. annzelaris only from the Oono and Tobetsu rivers, southern Hokkaido: in 5 (60- 67mm in body length) out of 59 fish (the middle-reaehes type, 50- 85mm, August 20, 23 and 27) from the Oono River; and in 3 (80- 87mm) out of 6 (the freshwater type, 70-100mm, August 26) and 7 (70-85 mm) out of 14 (the middle-reaches type, 70-85mm, August 26) from the Tobetsu River. It was not found in 20 (the freshwater type, 90--130mm, June 28) taken in Lake Toro, near Kushiro; 3 (the middle- reaches type, 45-80mm, July 30) taken in the Shokanbetsu River at Mashike; 20 (the middle-reaehes type, 70-75 mm, July 30) taken in the Shubunbetsu River at Mashike; or 3 (the middle-reaches type, 85-95 mm, August 8) taken in the Chitose River at Ebetsu, all in eastern and eentral Hokkaido. Desc?'i,pt･ion. 18 better specimens measured (Figs. 8-13). Body elongate, aspinose, 1.40-2.90 by O.36-O.70; forebody O.44-O.70 leng, 27- 35C!'i･ of total body length. Several pairs of gland cells (frontal or pharyn- geal or both) present in esophageal region. Oral sueker round, sub- terminal, O.11-O.17 by O.13-O.20. Prepharynx very short. Pharynx ellipti- cal, O.06-O.08 by O.07-O.09. Esophagus short, O.05-O.16 long, bifureating fair}y anterior to ventral sucker; intestines uniting to open through a single ventral anus near posteTior end of body. Ventrai sucker globular, very slightly protruded, located at about anterior one-third of body, O.17-O.27 by O.19-O.31, with 3 pairs of finger-shaped marginal appendages; sucker width ratio 1': 1.33-1.73.

NII-Electronic Library Service JapaneseJapaneseSociety Society ofSystematicZoologyof Systematic Zoology

14 T. Shimazu

1

9

10

Figs. 8-13, Opecoelus ultigori sp. nov,, gravid speeimens from Chaeitogobitts a,nnutar･is (the freshwater and middle-reaches types) frorn the Tobetsu River, Kamii-so, southern Hokkaido. 8. Entire worm, holotype, ventral view. 9-10. Anterior part of body, paratypes, showing anterior extent of vitellaria, ventral --12. viewi- 11. Ventral sucker, paratype, ventral view.- Termlnal genitalia, paratype, ventral view. 13. 0varian complex, paratype, dorsal view. (Scale bars: O.4mm in Figs. 8-10; O.2mm in Figs. 11-13,)

Testes subspherical, entire or sometimes slightly indented irregularly, tandem, in middle one-third of hindbody, O.10-O.27 by O.20-O.43. Cirrus pouch small, museular, thiek-walled, not extending posteriorly beyond left intestine, O.06-O.10 by O.03-O.04; internal seminal vesicle short, tubular; pars prostatica small; cirrus short. External seminal vesicle elongated-claviform, lying free in parenchyma, extending only just to posterior border of ventral sucker, O.24-O.43 long, surrounded partly by gland cells (prostatic?). Genital atrium srnall. Genital pore sinistro-

NII-Electronic Library Service JapaneseJapaneseSociety Society ofSystematicof Systematic Zoology

Opecoeline Trematodes of Japanese FTeshwater Fishes 15

submedian, a little prebifurcal. Ovary transversely reniform, median or submedian, just pretesticular, O.08-O.16 by O.l6-O.35. 0otype-eomplex preovarian. LAuRER's eanal running transversely between ootype and ovary. Seminal receptaele absent･; uterine seminal reeeptaele present. Uterus preovarian, with a few intercecal folds ; metraterm short, with a sphineter. Eggs not so many, 58-64 by 36-40 ptrn in balsam. Vitelline fol]icles rather small, reaching anterierly frorn level of posterior border of ventral sueker to midlevel of esophagus, eonfiuent posttestieularly, rarely with a few follicles located dorsal and anterior to ventral sucker; vitelline reservoir anterior or anterodextral to ovary. Exeretory vesiele reaehing to ovary; excretory pore dorso- or postero-terminal. llost. Cha･enogobius an7zz{lao"is (the middle-reaehes type, type host; and the freshwater type) (Gobiidae). Sites of infection. Intestine and reetum (aecidental:t-). Localities. The Tobetsu River (type loeality), Kamiiso, and the Oono River, Oono, southern Hokkaido. Type se}'71es. NSMT-Pl 3114 (holotype);2933, 3107-3113 and 3115- 3117 (20 paratypes). Renz･ai"ks. The anterior extent of the vitellaria varied Iargely from speeimen to specimen. Out of the 21 speeimens examined, IO had the vitellaria distributed anteriorly into the forebody but not to the pharyn- geal level; 7, to the bifurcal level; and 3, only just to the level of the posterior border of the ventral sucker. In O. variabilis, the anterior limit of distribution of the vite]laria ranges from the bifurcal level to the posterior margin of the ventral sueker, and the vitellaria do not extend as far anteriorly with increasing body size (CRIBB, 1985). This tendeney was not clear in the present new species. Disczession. Opeeoelzes ukigo7ul sp. n. is most closely similar in morphology to O. 7n･ut2t YAMAGuTI, 1940, and O. va7"iab･ilis CRIBB, 1985, 'inzetze out･ of many known speeies of Opecoelus. It differs from O. (YAMA- GuT'I, 1940; the type series, MPM Coll. No. 22135) mainly in the testes loeated near the posterior one-third of the body instead of the middle, and the external seminal vesiele being shorter and extending only just to the posterior edge of the ventral sucker instead of further posteriorly than it er about halfway between the ventral sucker and ovary. It is also separated from O. variabilis (CRIBB, 1985) mainly by a laTger body, a shorter external seminal vesicle, longer finger-shaped appendages of the ventral sueker and smaller eggs (58-64 by 36-40 ftm instead of 67-77 by 43-48ptm). The species is named after the Japanese name for the host, The new speeies was found in the fish caught in the strictly fresh-

NII-Electronic Library Service Japanese SooietySociety of SystematicSystematio Zoology

16 T ．Shimazu described water region of the Oono and Tobetsu rivers ． All the hitherto s ・ … ・ ・ m ・・i・ ・ fi・h ・s ・ xcept f・ r O ・・ α 磁 靦 ε 、pecies ・ f th ・ g ・nu ・ are p iti t ， CRIBB 1985 ）． which completes a freshwater life cycle in Australia （ ， of MANTER （1963） recorded a trematode as O ．7照 加 from two species fishes in Fiji bu 七 its life cycle is unknown ． There is the freshwater ， specles ． possibili 七y that the present trematode is also a 七rue freshwater 1 a1 七hough both 七he freshwater and According 七〇 IsHINo （per ．eom ．）， ） ・ amphidromous − α nn ？t， γ hos 七 fishes， are ， middle reaches 七ypes of C ． la is， the … w ・ ag ・ i・ ・nce th ・ have a ・cend ・d th，y 。 、。 。 llyn ・ver ret ・ ・n t lt ter ， y − host individuals 60 87 mm from salt to fresh water ； and 2 ） the infected （ ・ d ・ ・ ing th ・ m ・nth ・ ・f J・ ly ・ nd in b 。dy l。 ngth ） ・aught ・in th・ tw ・ river Augus 七 1984 ， are considered to have been 2 十 〇 r 3 十 years old ， having ， August ・ migra 七ed from salt 七〇 fresh water during the months of July and ， 0r having spent as long as two or 七hree years in fresh 19810r 1982 ， 七he trematode water ． They Inos 七 presumably acquired the infection with during the freshwater life after the upstream migration ． The life cycle ・ of the trematode remains to be elucida 七ed ． The species occul s in southern Hokkaido ．

摘 要 − 一．．一 c α ecum Di ・n ・r ° ・ ti・ ・ 嶋 津 武 （長 野 県 短 期大 学 ） 畔 産 淡 水 魚 類 に 寄 生 す る c の に つ い て ． s α ccus お よ び Opecoetus 属 （OpecGelidae： Opeeeelinae） 吸 虫 一 な ち ， Coitocaecum ptα 日 本 産 淡 水 魚 類 に 寄 生 し て い る 3 種 の 吸 虫を 記 載 し た ，す わ EGucHI 1931 SHIMAzu・1980 お 1926 」Dime γ os α ccus oncorhynchi （ ， ） giorehis OzAKI ， ， ． る 科 ，亜 科 よ び 新 種 の Opecoelus 醜 匂 o 悔 （Opecoelidae： Opecoelinae）で あ る 関連 す 型 の ウ キ ゴ リ お よ び 属 の 標 徴 を 記 述 し た ．新 種 O ．ukigori は 北 海 道 南 部 の 淡 水 型 と 中 流

α ・ ・BB 1985 mut ・・ ・MAGucH ・ 1940 お よ び 0 ・v riabitis C ， か ら見 出 し た ．本 種 は 0 ． Y ， 嚢 の 長 さ ， の 突 の 長 さ ， 精 巣 の 位 置 ， 外 部 貯 精 に 近 似 す る が ， 体 の 大 き さ や 腹 吸 盤 指 状 起

の が あ る ． 卵 の 大 き さ に よ っ て 区 別 さ れ る ．本 種 は 淡 水 種 可能 性

Reference5

・c ・ ° fW ・ ・ t P ・ ki・t・ n ・ ・D ・ ipti n BI ・ ・ E ・ E M ．1972 ， M ・ ・i・ e fi曲 trem ・ t・ d … VIII Q ， ・ w ・ n ・ ・ Pseu ・Z… 伽 ・ ec ・wn f・・m 且 ・h … f 。fthi ，t。 en n 。w ，p ・ 。 i・ ・ i・ ・ 1・ dingan g R ・KHATooN ・4 and KALKABAD ・ M ． R ． REHANA ， ， ・ ワ In BIL （ F ． ， SAEED ， ， Karachi ． IEEs ， of H eds ． Helminth Parasites of Some Vertebrates Chiefly from Fishes S。 ． （ ）， ． Pakistan 40 ． Agricultural Research Counci1， Karachi West ， pp eab … d ・f Can ・ da ・ BRAY R ． A ．1979 ． Dig ・ nea i・ m ・ ・i・ ・ fi・h ・ ・ f・・ m the ea ・tern ・ ， − 」 ．na ・t， H ぜst ，， 13 ： 399 431． 1987． Some helminth parasites of mar 加 e fishes of South Africa ： family ． Ibid．21 ： 1049− 1075 ． Opecoelidae （Digenea ） ， ¢ s ” αア α 百8 sp ・ nov ・ T ． H ， 1985 ． The life cycle and biology of Opecoelt i bf ・ CRIBB， − ｛st 」 ： 728． （Digenea ： Ope じ oehdae ）． At ． ． Zool．，33 715

一 NII-ElectronicN 工 工 Eleotronio Library Service JapaneseJapaneseSociety Society ofSystematicof Systematic Zoology

Opecoeline Trematodes of Japandse Freshwater Fishes 17

CRewcRoFT, P.VL'. 1951. Notes on the taxonomy of the genus Coitocaecu7n NIcoLL, 1915 (Opecoelidae). J. Parasitol., 37: 251-256. DoLLFus, R. PH. 1960. Reeherches exp6Timentales sur Nieolla ga,llica (R,-PH. Do-Fus 1941) R.-PH. DoLLFuss 1958, sa eereaiTe eotylicerque et sa m6tacercaiTe progen6ti- s.f. Coitocaee- que. Observations sur la famille des Coitocaeeidae Y. OzAKI 1928, inae F. PecHE 1926. T'rematoda Podocotyloidea et sLn' les cercaires cotylicerques d'eau douce et marines, An7t. Pa7'asitoi., 35: 65-117. AllocTeadii{m EGucm, S. 1931. [On a new speeies of the trematode genus parasitie in Onco'nhynchus inaci'ostowzies.] Niho7i Kiseichztgakka･i Kie'i, (3) : 20-22. (In Japanese.) 1932. Studies en some parasites of O?tco･}'hy7zch?･ts in Japan. I. A new trema- "amage". tode frem Oitco･rhyizchus 7naco"ostomz{s or Osaka･ Koto Igaku SeTno)zoot- gakA;o Zassh'i, 1 : 24-29, GiBsoN, D.I. 1976. Monog'enea and Digenea from fishes. DiscoveTy Rept., 36: 179- 266, pL 18. GIBsoN, D.L and BRAy, R.A, 1982. A study and reorganization of Plagiopor･us STAb'FoRE, 1904 (Digenea: Opecoelidae) and related genei'a, with special referenec to forms from European Atlantic waters. J. nat. Hist., 16: 529-559. INsTITUTE oF HyDRoBIoLoGy, HuBEI PROvlNcE, CmNA 1973, [An Illustrated Guide to Fish Diseases and Pathogenetic FauTia and Flora in Hubei Provinee.] 456pp. Kexue Chubanshe, Beijing, (In Chinese.) KoMIyA, Y. and TAJIMI, T. 1943. Metacereariae from Macrobrachiu7n ntpponensis [sic] (DE HAAN) ln Shanghai area and their exeretory system. Shaityha,i Shi2en- kagaku Kenkyusho Jho, 13: 45-57, pls. 1-4. (In Japanese, with English summary.) MANTER, H. W. 1947. The digenetic trematedes of marine fishes of Tortugas, Florida. Ao}?.. nfidl. Natztral., 38: 257-416, - 1963 Studies on digenetie trematodes of fishes ef Fiji. II. Families Lepoereadi- idae, Opistholebetidae, and Opeeoelidae. J. Pa･rasitol., 49: 99-113. MEHRA, H.R. 1966. Revision of Alloereadioidea NIcoLL, 1934. Part II. Families: Opecoelidae OzAKi, 1925, Opistholebetidae FuKul, 1929, Allocreadiidae STosslcH, 1903, BunodeTidae NicoLL, 1914, Aeanthocolpidae LinIE, 1909 and Pleorchiidae PocHE, 1925, 46pp. Author's publication, Allahabad. NIcoLL, W. 1915. The trematode paTasites of North Queensland. III. Parasites of fishes. Parasitolog!l, 8: 22-41, pls.4-5. OKABE, K, and SHIBuE, H. 1952. 0n O･ncomelan･i.a otosophora RoBsoN and two species of inetacercaTiu [sic] found in the fresh-water shrirnp, Neocuo'id'ivza. denticu.tata (DE HAAN) collected in Katayama, Hiro$hirntt Prefeeture. Kuntme Iga･kka･i Zasshi, 15: 607-611. (In Japanese, with English summary.) OzAKI, Y. 1925. Prelirninary notes on a trematode with anus. J. Parasitol, 12: 51- 53, pL 7. 1926. [On some new speeies of trematodes of fTeshwater fishes from Japan (PreliminaTy repert).] Zool. Mag., Tokyo, 3S: 124-130. (In Japanese.) 1928. 0n some trematodes with anus. Japn. J, Zool., 1: 5-33. 1929. Note on Coitoeaeeidae, a new trematode family. An?tot. 2ool. o'apo"., 12: 75-90. PETERs, L.E. 1957. An analysis of the trematode genus AUoareadi2{m. Looss with the deseription of Allocreadiitm neoten'icum sp. nov, from water beetles. J. Para･sitog. 43: 136-142. PocHE, F. 1926. Das System der PlatodaTia. ATch. Na･t･u.rgesch., Abt. A, 91: 1-458, pls,1-7 (1925).

NII-Electronic Library Service JapaneseJapaneseSociety Society ofSystematicZoologyof Systematic Zoology

18 T. Shimazu

ScHELL, S. C. 1976. The life histoTy of Ne2peTeella tewisi ScHELL 1974 (Trematoda: Opecoelidae), a parasite of the northern squawfish, and the smallmouth bass. J. Pao-asitol., 62: 894-898. SHiBuE, H. 1953. 0n some trematode larvae found in the fresh-water shrimp, Neocaridi?za deoiticz{tata (DE HAAN) eollected in Kurume District, Kyushu. Kurunte Igakkai Zassiti, 16: 780-790. (In Japanese, with English summai'y,) SHIMAzu, T. 1980. Di･mei'osa.cezas gen. nov. (Digenea: Opecoelidae), with a redeserip- tion of its type species, Pimerosacc?ts o'n.coi-hunchi. (EGucHI, 1931) eomb. nov. Jap7z. J. Parasitol., 29: 163-168. 1981. Metaeereariae of Neenotopoo'zas traehz{ri (Trernatoda, Lepocreadiidae} parasitic to Eztphausia･ si'tnil･is (Crustacea, Euphausiidae). ZooL May., Tokuo, 90: 254-257. 1988. Trematodes of the genus Allocread･iu"･z (Alloereadiidae) from fresh- water fishes of Japan. Bull. natn. Sci. Mus., Tokyo, Ser. A, 14: 1-21. and SHIMuRA, S. 1984. Paralep･idapeden g. n. (Trernatoda: Lepoereadiidae>, with descriptions of metacercariae of Paralepidapedon heplognath･i (YAMAGuTI, 1938) eomb. n. and of two other species from sea urchins. Zool. Sei., 1: 809-817. SRIvAsTAvA, H.D. 1942. New allocreadiids (Trematoda) from Indian marine food fishes. Part IV. The morphology and systematie position of a new genus, Ho･r-to'e'nza, of digenetie trernatodes. Paras･itoZogy, 34: 128-132. STUNKARD, H.W. 1931. Further observations on the oeeurrenee of anal openings in digenetie trematodes. Z. Parasite7zkd,, 3: 713-725.

U.S. DEPARTMENT eF AGRIcuLTuRE 1952. I7zdex-Catulogue of Medical and Vete･rina･ry

Zoology. Part 17. Authors: U to Wyville, p. 5560. 1967. Ibid. Subjects: Ti'ematoda and Trematode Diseases. Part 6: Super- genera and geneTa N-Q, pp. 1082, 1157. WigNiEwsKI, L.W. 1933. Przyezynek do systematyki Coitocaecidae (Trematoda)･ Nicollia n. g., 02akiec n. g., Coitocaecu･m･ p･roa'vitien･z n, sp. Sprawox. pot. Akad. Umiei., 38: 34-35. Cited by THE U.S. DEpARTMENT oF AGRIcuLTuRE (1952, 1967). 1934. Beitrag zur Systematik der Coitocaecidae

1942. Ditto. Part 39. Trematodes of fishes mainly from Naha. Tra･ns. b-iogeoyr. Soc. Ja･pan, 3: 329-398, pl. 24. 1958. The Digenetic Trematodes of Vertebrates, Part 1. S･ystema Helmin- thu･m, 1: 1-979. Interscience Publishers, New York. 1971. Synopsis of Digenetic Trematodes of Vertebrates, 2 vols., 1074pp., 349 pls. Keigaku Publishing Co., Tokyo. and H. NIslMuRA 1944. 0ne nematode and two trematode larvae from Cari[li"Lt denticula･ta DE HAAN. Huku.oka Aeta med., 37: 1-6, 411.

NII-Electronic Library Service JapaneseJapaneseSociety Society ofSystematicZoologyof Systematic Zoology

Opecoeline Trematodes of Japanese FTeshwater Fishes 19 . ZHuKov, E.V. 1972. New genera of trematodes from marine fishes of India. Paraz･1- tolegiya, 6 : 346-350. (In Russian, with English summary.)

Azttho･r's adcl･ress: Takeshi SHiMAzv, Nagano-ken Junier College, 49-7, Miwa 8-ehome, Nagano 380, Japan.

NII-Electronic Library Service