New Monogenetic Trematodes from Hawaiian Fishes, IP

SATYU YAMAGUTI

IN THIS SECOND REPORT are described sevennew species of monogenetic trematodes belong­ing to six new genera, two of which representeach a new subfamily. One of these two speciesseems to occur rather uncommonly on theHawaiian flying fishes; so far I have managedto collect only four specimens after a longsearch. Although the host of this worm is apelagic fish, its parasite fauna seems ratherendemic in character, inasmuch as the mono­genetic and digenetic trematodes found on orin the Hawaiian flying fishes are quite differentfrom those occurring in the all ied host speciesin the neighboring waters. This fact stronglysuggests that the distribution of the Hawaiianflying fishes is not very extensive.

All the other new genera of Monogenea tobe reported by me from Hawaii will be de­scribed in a monograph upon Hawaiian mono­genetic trematodes, so that the present reportis the last of the series for new Hawaiian mono­genetic genera to be described in short articles .

Thanks are due to all the institutions andpersons concerned in my survey of Hawaiiantrematodes, including the National ScienceFoundation, the University of Hawaii, myassis­tant, Mr . Shunya Kamegai, and my wife, IkukoYamaguti.

The new species described herein are assignedto the following families and subfamilies:

I. Capsalidae Baird, 1853

Benedeniinae Johnston, 19311. Pseudaliobenedenia apharei n. g., n. sp.2. Psendallob eneden in opakapaka n. sp .3. Lageniuaginopseudobenedenia etelis n.

g., n . sp.

II. Discocotylidae Price, 1936

Opisthogyninae Unnithan, 19624. Metopisthogyne sphyraenae n. g., n . sp .

1 Contribution No . 248 from Hawaii Institute ofMarine Biolog y. Un iversity of Hawaii, supported bya grant (GB-2992) from the National ScienceFoundation. Manuscript received May 3, 1965.

III. Pterinotrematidae Bychowsky and Nagi­

bina, 19595. Pseudopterinotrema albulae n. g., n. sp.

IV. Axinidae Unnithan, 1957

Sibitrematinae n. subfam.6. Sibitrema poonui n. g., n . sp.

Cypselurobranchitrematinae n. subfam.7. Cypselurobranchitrema spilonotopteri

n. g., n. sp.

1. Pseudallobenedenia apharei n. gen., n. sp.Fig. 1

HABITAT: Gills of Aphareus rutilans ; Hawaii.

HOLOTYPE : U. S. Nat. Mus. H elm . ColI.,S. Y. No. 45 .

DESCRIPTION (based on 21 whole mounts):Body approximately fusiform, 2.6-5.3 mmlong, with maximum width of 0.7-1.9 mm atabout testicular level. Posterior extremity ofbody proper attenuated to a flap covering opis ­thohaptor dorsally. Opisthohaptor discoid, usu­ally projecting a little beyond posterior end ofbody proper, 0.43-0.8 mm longitudinally ex­cept for scalloped marginal membrane 20-80~l

wide, with a central pit 0.1-0.15 mm in diame­ter; on the concave ventral surface there arethree pairs of anchors, but no defini te septa orridges, although several symmetrical radiatingexcretory vessels are seen bifurcating or not attheir submarginal ends ; anterior anchor 28-37~

long from tip to posterior end , situated postero­lateral to central pit; two posterior anchorsclose together near posterolateral edge of opis­thohaptor; longer J-shaped medial one slender,18-33~ long ; shorter lateral one hook-shaped,with bifid root, 14-21~ long. Prohaptors ellip­tical, saucer-shaped, 0.54-1.0 X 0.24-0.48 mm ,connected dorsally by medianly incised frontalplate which never projects forward beyond theprohaptors. Mouth opening ventrally at levelof posterior end of prohaptors, with one pair ortwo of eyespots dorsally. Pharynx muscular, in­cised anteriorly into five lobes, more or less

419

4 20 PACIFIC SCIENCE, Vol. XX, October 19 66

ABBREVIATIONS USED IN FI GURES

AB atrial bulb GI genito-intestinal canal PH proh aptorAG apical gland GO Goto 's organ PM pars muscul arisAP accessory piece GP genital pore PR pros tatic reservoirAS axial scleri te HC head cone RS receptaculum seminisBC bulbus cirr i I intestine S suckerBE bulbus ejaculatorius IE intestinal branch SG shell glandC cirrus ID intestinal divertide T testisCA caudal appe ndage LL larval lappet TG termin al genitaliaCL clamp M mouth U uterusCP cirrus pouch 0 ovary V vaginaCS crown of spines OC eyespot VD vas deferensCV d amp valve OH opisthohaptor VGD vaginal ductDE ductus ejaculatorius OS oral sucker VP vaginal poreE egg P pharynx VR vitelline reservoi rES esophagus PC pros tatic cell VT vitelline glandGA genital atriu m PD prostatic duct VTD vitelline duct

constricted laterally near broadly rounded pos­terior end, 0.22 - 0.52 X 0.24-0.65 mm. Esoph­agus short ; each intestinal limb giving off moreor less dendritic outer branch es, of which theanterior pair extends into the frontal plate,almost meeting in the median line; posterior­most pair sends out several outer branchesreaching lateral edges of body and a fewshor ter inner branches probably anastomosingeach other ; no anastomosis between two mainintestinal limbs posteriorly.

Testes oval to elliptical, 0. 28-0.8 X 0.18-0.5mm, directly juxtaposed, largely in posteriorpart of middle third of body, with paired mul ­tinucleate Goto's glands immediately behind.Vas deferens running forward along left mar­gin of ovary, convoluted just medial to left in­testinal limb, then crossing uterus dorsally andcoming to right side of median line, where itenters the cirrus pouch along with the prostaticreservoir and finally unites with the prostaticduct to lead into extremely long ( 2-3 mm ormore) spicular cirrus. Prostatic cells massedaround distal portion of vas deferens and pro­static reservoir which is elliptical, 0 .1 mm longby 0.05 mm wide in the type and lies longitu­dinally alongside the vas defer ens. Cirrus pouchsomewhat muscular , small (exact length notdetermin able) , containing windin g vas deferens

and more or less convoluted prostatic duct; bothducts joining together to form cirrus which isenclosed throughout its length in the thin­walled, tubul ar, genital atrium, and may or maynot project out of the genital pore. The genitalatrium is continued from the wall of the cirruspouch with the same diameter as the latter, buttapers into a very long, narrow tubul e whichruns backward and then curves toward the leftin front of the transverse vitelline duct; it turnsback on itself here to follow the same course asits proximal portion , and after passing besidethe cirrus pouch proceeds straight obliquely for­ward to open ventrosublaterally at the level ofthe posterior end of the pharynx on the leftside.

Ovary subglobular, 0.08-0.28 X 0.1- 0.25mm, situated medianly between anterior endsof testes. Germiduct arising from anterior endof ovary, joining duct from vitelline reservoirand leading into ootype which passes into along, wind ing, muscular uter ine duct. Ut erusproper forming diverticle-like expansion whendistended with eggs ; distal portion of uterusproper runn ing obliquely forward along withgenital atrium, opening together with latter bya common pore . Shell gland cells developedaround ootype. Eggs mostly rounded conical,but rounded tr iangul ar in flattened condition,

FIG. 1. Pseudallobenedenia apbarei n. g ., n. sp . I A, Holotype, ventral view ; 1B, haptoral anchors ofparatype; l C, terminal genitalia of paratype, ventral view.

FIG. 2. Pseudallobenedenia opakapaka n. sp. 2A, Holotype, ventra l view ; 2B, haptoral anchors; 2C, ter­minal genita lia, ventral view.

New Monogenetic Trematodes, II-YAMAGUTI 421

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Ie

422 PACIFIC SCIENCE, Vol. XX, October 1966

TABLE 1

DIFFERENTI ATI ON OF Pseudallobened eniaFROM Allobenedenia

with extremely long, very fine, antipolar fila­ment at base, 0.1-0.125 X 0.09-0.11 5 mm asmeasured in life and in lactophen olglycerinjelly. Vitelline follicles extend ing in lateralfields from level of posterior part or end ofph arynx to base of posterior flap covering opis­thohaptor, confluent in median line betweentestes and opisthohaptor, intruding into smallarea between transverse vitelline ducts andtestes ; transverse vitelline ducts united rnedi­anly, form ing inconspicuous vitelline reservoironly 20- 110/-l anteroposteriorly. Vagina open­ing ventral to uteru s by a very small pore alittle behind intestinal bifurcation; vaginal ductwinding along with vas deferens medial to leftintest inal limb ; receptaculum seminis vaginaeoval, 50-150 X 30-110/-l, lying between lefttransverse vitelline duct and ootype; seminalduct connectin g seminal receptacle with vitel­line reservoir very shor t. Excretory vesicle fun­nel-shaped, symmetrical, opening dorsally atlevel of intestinal bifurcation.

DISCUSSION: This genus very closely resem­bles Allobenedenia Yamaguti , 1963 in grossanatomy, but differs in minor details as shownin Table l.

The present species differs from P. opakapakato be described below in that the genital atrium

Allobenedenia Pseudallobenedenia

2. Pseudallobenedenia opakapaka n. sp.Fig. 2

H ABITAT: Gills of Pristipomoides microiepis( local name "opakapaka" ) ; Hawaii.

HOLOTYPE: U. S. N at. Mus. H elm. ColI.,S. Y. N o. 46.

DESCRIPTION ( based on thr ee whole mounts) :Body elongate, distinctly constricted immediatelybehind prohaptor, 3.0-5.5 mm in total lengthincluding opisthohaptor, with maximum widthof 0. 1-0.15 mm at level of testes. Opi sthohap­tor bell-shaped, 0.6- 0.8 mm in transverse di­ameter, provided with a scalloped marginalmembrane. There are three submedian pairs ofweakly developed anchors on the inner surfaceof the posterior half of the opisthohaptor; an­terior anchor rod-shaped, 40-50/-l long, middleand posterior anchors a little apart from the an­terior, close together near haptoral margin;middl e one somewhat undulating, barbed dis­tally, 40-43/-l long ; posterior one hook-shaped,18-2 5/-l long. Prohaptor oval, saucer-shaped,glandular, 0.21-0.28 mm long; between thetwo haptors is seen the trun cate head end levelwith the anterior end of the haptor. Two pairsof eyespots anterodorsal to pharynx. Pharynxsubglobular, without constriction, 42-58 X 52­62/-l. Esophagus very shor t, surrounded on eachside by postpharyngeal cells, whose ducts ap­pear to open into the ph aryngeal lumen closeto its posterior end. Int estinal limbs with com­paratively long, subdivided, outer branches, ter­minating separately a short distance away fromposterior end of body.

T estes elliptical, juxtaposed at anterior par tof middle th ird of body, 0.3 7-0. 7 X 0.17-0. 28mm, with paired Goto's glands immediately be­hind. Multinucleate organs like Goto's werefound immediately in fron t of the testes andbeside ovary. Vas deferens convoluted betweenleft intestinal limb and shell gland complex,then forming a very long horseshoe-shaped loopacross uterus and cirrus pouch dorsally, pene­trating cirrus pouch at its anterior base, finallyjoining prostatic duct at posterior end of cirruspouch. Cirrus pouch cylindrical, 0.2- 0.7 mm

is much longer, often convolut ed, and containsan extremely long cirrus. The unusually longand wide uterus in P. apbarei is worth notin g.

absent

extremelylong

extrem elylong,convolutedor straight

submedian,postbifurcal

welldeveloped

no definitereservoi r

not extremelylong

pres ent

long

marginalor sub­marginal,prebifurcal

absent

saccular,verydistinct

Front al hood

Cirrus

CHARACTER

Genital atrium

Vaginalopening

Receptaculumseminis

Vitellinereservoir

New Monogenetic Tr ematodes, 1I-Y AMA GUTI

long, arcuate, strongly muscular, swollen at itsforwardly directed base, situated longitudinallybetween right intestin al limb and uterus , con­taining prostatic duct and vas deferens, both ofwhich are straight , narrow, and close together,though convoluted at the anterior base of thecirrus pouch. Cirrus spicular, long, enclosed insheathlike genital atrium which extends fromthe posterior distal end of the cirrus pouch tothe genital pore along the dorsal side of thecirrus pouch. This overlapping portion is shownseparately in the figure . Prostatic reservoirelongate, 80-90 X 100-1 30/-l., situated imme­diately in front of base of cirrus pouch. Genitalpore common, just posterosinistral to pharynx.

Ovary subglobular, 0.17-0.27 X 0.17-0.22mm, situated between two testes and vitellinereservoir. Shell gland complex strongly devel­oped. Uterus distended with eggs. Eggs roundedpyramidal, with triangular base in balsammounts , 0.12-0.14 X 0.12-0.1 5 mm in life ,with very fine, long filament at one basal cor­ner. Vagina opening ventrally in left submedianline a little posterior to intestina l bifurcation;vaginal duct thick-walled , running straightbackward and opening into oval seminal recep­tacle which measures 1OO~l by 80/-l. in the type.Vitella ria coextensive with intestinal limbs andtheir branches; vitelline reservoir transverselyelongated, not forming a compact mass, 60-90/-l.anteroposteriorly. Paired excretory vesicles con­spicuous at level of uterus.

DISCU SSION : The differences between thisspecies and the type species are given in thediscussion of the type species.

Pseudallobenedenia n. gen.

GE N EIUC DIAGNOSIS: Capsalidae, Benedenii­nae. Opisthohaptor discoid, not septate, withscalloped margina l membrane, armed with threepairs of anchors. Prohaptors not enclosed inhoodlike frontal plate. Pharynx muscular, lobedanteriorly; intestinal limbs branched, not con­fluent posteriorly, though their posterior innerbranches may anastomose. Testes juxtaposed ;vas deferens convoluted medial to left intestinallimb. Prostatic cells and reservoir outside cirruspouch. Cirrus pouch long; cirrus extremelylong, enclosed in extremely long, tubular, genitalatrium . Genital pore common, sublateral or sub-

423

median, level with posterio r end of pharynx orfarther behind . Ovary immediately pretesticular.Eggs rounded conical or pyramidal, with verylong filament at base or basal corner. Vite llariaextensive; vitelline reservoir inconspicuous. Va­gina opening submedianly ventral to uterus atpostbifurcal level ; receptaculum seminis vagi­nae well developed . Gill parasites of marineteleosts.

T YP E SPECIES : P. apharei n. sp., on Apbar­eus rutilans; H awaii.

OTHER SPECIES : P. opakapaka n . sp., on Pris­tipomoides microlepis; H awaii.

3. Lagenivaginopseudobenedenia etelisn. g., n. sp.

Fig. 3

HABITAT: Gills of Etelis carbtl1lculus (loca lname "onaga" ) ; Hawaii.

H OL OTY PE : U. S. Nat. Mus. Helm. ColI.,S. Y. N o. 47 .

DESCRIPTION (based on three whole mounts):Body elliptical , flat, 2.9-4.3 mm in total length ,1.8-2 .3 mm wide in midregion; head and neckregion contracted and well separated fromtrunk. Opisthohaptor elliptical, 0.53-0.75 mmlong, with finely scalloped marginal membrane30-70/-l. wide and three pairs of anchors ; num ­ber of marginal hooklets not determined; ante­rior anchor 0.13-0.17 mm long, sharp -pointedanteriorly, nonalate, with two small bluntstumpy processes of unequa l lengt h at posteriorend ; midd le and posterior anchors definitelysmaller than anterior ; middle one slender, 50­80/-l. long, with undulating root and minuteterminal claw ; posterior one enlarged and flat­tened from side to side basally, 30-40/-l. long,terminating in a minute claw. Prohaptors saucer­shaped , paired, close together, 0.19-0.23 X0.36-0.42 mm, conta ining glandular tissuewhich extends not only backward but also in­ward to be confluent in the median line pos­terior to somewhat incised frontal margin. Twopairs of eyespots present anterodorsa l to phar ­ynx. Pharynx spherical, 0.27-0.29 X 0.3-0.31mm, glandular rather than muscular, papi llateinternally. Esophagus practically absent; cecawith numerous dendritic outer branches, notconfluent posteriorly.

424 PACIFIC SCIENCE , Vol. XX, October 1966

FIG. 3. Lagenivaginopseudobenedenia etelis n , g.,n. sp. 3A , Holotype, ventral view ; 3B, haptoral an­chors of holotype; 3C, term inal genitalia of holotype,ventral view.

Testes elliptical, 0.31-0.5 X 0.2-0.34 mm,juxtaposed contiguously at anterior part of mid­dle third of body. Rudimentary Goto's organpresent. Vas deferens convoluted immediatelyanterosinistral to vitelline reservoir, then wind­ing along posterior wall of cirrus pouch, which

VTn

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38

c

it penetrates from the dorsal side ; after enter­ing the cirrus pouch it pursues a short windingcourse, then a long straight course alongside thedistal portion of the prostatic duct, with whichit finally unites to form the ejaculatory duct.Cirrus pouch subcylindrical, thin -walled, 0.25 ­0.4 X 0.0 8-0.1 mm, curved transversely behindpharynx, containing at its base a small, tubular,prostatic reservoir and cylindrical pars muscu­laris of prostatic duct which is 0.1-0.13 mmlong and provided with a thick coat (30 -6011wide) of fine circular muscle fibers. Prostaticcells distributed around base of cirrus pouch .Cirrus elongate conical, pointed, 0.42 X 0.06mm in the type ; it mayor may not project outof the geni tal pore. Common genital pore pos­terosinistral to pharynx, a little (0.1 mm in thetype) away from nearly right angle formed byneck and trunk.

Ovary subglobular to oval, 0.15-0.3 X 0.09­0.22 mm, situated medianly, with its posteriorend intercalated between two testes. Ootypespher ical, 0.15 -0. 2 rom in diameter, providedwith epithelial lining ; uterus proper well sepa­rated from ootype, 0.2 mm wide in the type,openin g into common genital pore by a funnel­shaped passage. No eggs observed. Vitellari aconsisting of small follicles, coextensive withintestine , wide apart anteriorly , but confluentposteriorly ; paired longitudinal collecting ductsdistended with yolk cells; transverse duct maybe narrower, up to 7011 wide in the larger para­type, not forming a definite reservoir. Vaginalageniform, 0.17 mm wide in the type, muscularat its narrow neck, situated between uterus andright intestinal limb, opening almost rnidven­trally behind cirrus pouch. Seminal receptacleoval, 0.1 X 0.055 mm in the type, betweenvagina and vitelline reservoir. Excretory systemnot made out.

DISCUSSION: This genus, characterized by thehead and neck being marked off from the trunkand by the peculiar structure and position of thevagina, bears a certain resemblance to Pseudo­benedenia Johnston, 1931, especially in the pro­static vesicle being enclosed in the cirrus pouch,but it seems justified to separate the genus inquestion from Pseudobenedenia on the basis ofthe above mentioned features. The compoundgeneric name refers to the lageniform vaginaand close relationship to Pseudobenedenia.

N ew Monogenetic Trematodes, II-YAM AGUTI

Lag eniuaginopseudobenedenla n. g.

GENERIC DIAGNOS IS: Capsa lidae, Benedenii­nae. Prohaptors consisting of pa ired glandu larsaucers placed close together. Op isthohaptordiscoid, asep tate, with scalloped marginal mem­brane, armed with three pairs of anchors. Eye­spots pr esent. H ead and neck region much nar­rower th an trunk and well marked off from it.Pharynx sph erical, without constr iction, rathe rglandular, papillate interna lly. Intestinal limbswith dendritic oute r branches, not confluentposteriorl y. Testes juxtaposed, entire. Vas def ­erens strongly convoluted in fron t of left trans­verse vitelline duct, passing transversely beh indcirrus pouch and penetrating it near its base.Cirrus pouch cylindrical, extending transverselybehind pharyn x, containing small prostatic res­ervoir and well develope d pars muscularis ofprostatic duct at its base. Cirrus elongate coni­cal, pointed, pro jecting into th in-walled genitalatrium. Common genital pore ventrosubmedian,well apar t fro m body margin. Ovary entire, notseparated from testes by vitellar ia. Vitellaria co­extensive with intestine; no definite vitellinereservoir . Vagina lageniform , between uterusand right intestinal limb, open ing almost mid­ventrally behind cirrus pouch; seminal recepta ­cle well developed. Gill parasi tes of marineteleosts.

T YPE SP ECIES : L. etelis n. sp., on Etelis car­bunculns ; H awaii.

4. M etopisthogYl1e sphyraenae n. gen., n , sp.Fig. 4

HABI TAT : Gills of Sphyraena belleri (l ocalname "kawalea' ") ; H awaii.

HOLOTYPE : U. S. N at. Mus. Helm. Coll. ,S. Y. N o. 48 .

DESCRIPTION (based on five whole mounts) :Body 4.4--8 .9 mm long, slender, graduallywiden ed toward opisthohaptor which is 0.8-2.0mm long by 0.6-1.0 mm wide at base and bearsfour pairs of short-stalked clamps and a short,trapezoidal, median, caudal lappet providedwith three pairs of hooks. Clamp skeleton0.24--0.3 mm in transverse diameter, consistingof a very stout median spr ing, a pa ir of inn erbasal sclerites, two pairs of arcuate lateral scle­rites and a pair of accessory sclerites ; one prong

42 5

of median spri ng with three or four minuteholes, enlarged at apex in form of a trian gle;other prong-with anchor-shaped apex, may bebulbously swollen near its base. Of the cauda lhooks the larger outermost is 41-46[! long fromtip of root to height of curve of blade, and hasa curved guard a little shorter than root ; thesmallest middl e is 16-1 8[! long and has a com­paratively long root and a short curved blade ;the innermost is somewhat similar in shape tothe outermost and 25-28[! long. H ead rou ndedin fr ont, 0.16-0.32 mm wide, with ventra lmouth aperture and a pair of groups of glandducts at apex ; paired oral suckers aseptate, mus­cular , 70-93 X 58-72~, close together, fol ­lowed by ovoid nonm uscular pharynx 51-70[!long by 48-58[! wide; esophagus 1.0-2.0 mmlong, simple, wide, bifurcating just in front ofvaginal pore ; intestinal limbs with shor t sidebranches, terminating separately, one at base ofopisthohaptor and the other a little mor e pos­teriorly.

Testes small, ovoid, 93-162 in total number,extend ing in interintestinal field from ant eriorpart of middle thi rd of body to anterior half ofcaudal th ird, mostly preovarian, partly para­and postovarian . Vas deferens strongly windingin median field between testes and vagina; inthe region between the vagina and th e parsmuscul aris there are nume rous prostate cells,though th e pars prostatica is not distinctl y dif­ferent iated. Pars muscularis represent ing ejacu­latory duct, 0.35-0.45 mm long by 40-60[!wide, provided with strong transverse or spiralmuscle fibers, followed by muscular cirrus 0.18­0.26 mm long which is bulbously swollen nea rits distal end and projects into the nonmusculargen ital atrium in the type. Genital atrium open­ing on left margin of body at a distance of0.55-0.8 mm from head end .

Ovary tubular, long, folded back on itselfjust medial to left intestinal limb, 0.3- 0.4 mmlong lineally as a whole, arising about one-thirdof body length from posterior extremity. Ger­miduct giving rise to genito-intestinal duct be­fore join ing vitelline reservoir. This duct opensinto th e left intestinal limb a little anterior tothe distal end of the ovary. Uterus midvent ral,contain ing only one fusiform egg in the type .Eggs 0.17-0.18 mm long, with rigid bipolarfilaments 0.1 5-0.21 mm long. Vitellaria largely

426

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PACIFIC SCIENCE, Vol. XX, October 1966

FIG. 4. Met opishogyne sphyraenae n. g., n. sp. 4A, H olotype, ventral view; 48 and 4C, enlarged anteriorand posterior regions of holotype, ventral view; 4D, clamp of paratype ; 4£, anchors on caudal appendage ofparatype ; 4F, termin al geni talia of holotype, ventral view; 4G, vagina of paratype, ventral view.

N ew Monogenet ic Trematodes, II-YAMAGUTI

coextensive with intestine, commencing a littlebehind vagina l pore and terminating at base ofopisthohap tor ; vitelline reservoir Y-shaped, inovarian zone. Vagina funnel-shaped, strong lymuscular, sending out a short narrow duct oneach side of its anterior end. T his duct appearsto be connected with the anterior end of thelongitudinal vitelline duct of its own side, al­though no distinct connecting duct is seen.Vagin al pore middorsal, postbifurcal, providedwith a conspi cuous bulb of fine lamellar musclefibers, situated at a distance of 1.2-2.25 mmfrom head end .

DISCUSSION : This genus differs markedly fromOpisthogyne Unnithan, 1962, in the distribu­tion of the testes. In Opisthogyne the testes arelimited to the preovarian region, whereas in thepresent genus they are much more numerousand more extensive. The V-shaped ridges charac­teristic of Opisth ogyne and Gemmacaputia Tri­pathi, 1959, are absent in th e posterior part ofthe body in the present genus.

M etopistb ogyne n. gen.

GENERIC DIAGN OSIS : Discocotylidae, Opis­thogyninae. Body symmetrical, elongate, with­out V-shaped ridges posteriorly. Four pairs ofsimilar clamps of Gastrocotyle type. Termin allappet with three pairs of hooks. Esophaguslong ; intestine with side branches, terminatingseparately. Testes num erous, mainly preova rian,partly para- and postovar ian. Ductus ejaculate ­rius strongly muscular. Cirrus muscular, un­armed. Genital pore ventromarginal. Ovarytubular, fo lded back on itself in posterior halfof body; eggs fusiform, with filament at eachpole. Vit ellaria coextensive with intestine. Vag­inal pore middorsal, immediately postbifur cal.Gill parasites of marin e teleosts.

TYPE SP ECIES: M. sphyraenae n. sp ., on 5phy­raena belleri; H awaii.

5. Pseudopterinot rema albulae n. g., n. sp.Fig. 5

HABITAT : Gills of Albula uulpes; H awaii.HOLOTYPE : U. S. Nat. M us. H elm. ColI.,

S. Y. N o. 49 .DESCRIPTION ( based on 26 whole mounts) :

Body slender, cylindr ical, 1.75-2.4 mm in

427

length exclusive of haptoral clamps, up to 4.5mm in length including clamps, 0.12-0.26 mmwid e in ovariotesticular region. Opisthohaptorfan-shaped, asymmetrical, on posterior exten­sion of body proper, with nine pedunculateclamp s. As numbered from the right end of theopisthohaptor of the type th e first to the ninthclamp gave the following measurements, pre­senting different features respectively:

(1 ) First clamp 0.18 rom long, divided intoa caudal appendage bearing a pair of large sub­apical anchors 37-48fllong and two more, verysmall, apical hooklets 9- 15fl long, and a shorterclamp th an oth ers. This clamp consists of twoopposing valves fringed on each side withabout a dozen curved spines and supp orted bycomparatively short stout sclerites.

(2) Second clamp arising from commontrunk with first, 0.25 mm long, consisting ofa slender stalk about 0.2 mm long, and pro­vided on each side with membrano us fr ingesupported by a row of about a dozen acicularspines and a sing le axial sclerite ; apical clampvalve single, fringed with over a dozen curvedspines.

(3 ) Third clamp about 0.4 mm long fromits basal two-valved sucker to tip of doubleterminal clamp valve; its stalk supported by twounequal axial sclerites, one of which articulateswith the sclerite of the second clamp at the base,wh ile the other slender one articulates with thestronger axial sclerite of the four th clamp ;axial clamp valves pressed against each other.

(4) Fourth clamp 0.38 mm long, similar instructure to th e thi rd , with doub le apical clampvalve, bearing at base a two-valved sucker onthe right and a larval lappet on the left. T hislappet is a plump rod-shaped lobe 25-40fllongby 15-22fl wide and bears two pairs of verysmall larval anchors 12-17fl long.

(5) Fifth clamp 0.47 mm long from itsbasal sucker to apex which consists of twosimilar valves.

( 6) Sixth clamp 0.25 mm long, with doubleap ical valve similar in structure to that of third.

(7) Seventh clamp 0.23 mm long ; terminalclamp valves symmetrical.

(8) Eighth clamp about 0.18 mm long, withtwo separate apical valves and a common stalksupported by two para llel axial sclerites, of

428 PACIFIC SCIENCE, Vol. XX, October 1966

FIG. 5. Pseudopterlnotrema alubulae n. g., n. sp.5A, Holotype, ventral view ; 5B, two-valved sucker ;5C, anchors on caud al app endage of holotype ; 5D ,cirrus and its accessory sc1erites of paratype, dorsalview; 5E, egg .

which the righ t one articulates with the leftaxial sclerite of the seventh clamp and the leftone articulates with the extreme left ninthsclerite.

(9) Ninth clamp about 0.12 mm long andfr inged on each side with a row of spines likeother clamp stalks, but bears one apical clampvalve, although it has a two-valved sucker onthe left side of its base.

The above mentioned two-valved suckers,23-40!l wide and seven in all, are arrangedin a transverse row at the base of the clamps.Each sucker has a sclerotized frame consistingof four sclerites and appears 00 -shaped in pro­file.

Prohaptor circular, 0.2-0.47 mm in diameter,membranous, with somewhat crenulated marginand a simple middorsal cone 40-70!l long and40-70!l wide at base. Oral sucker 0.11-0.21 mmin diameter, opening at bottom of prohaptor ;prepharynx present ; pharynx always lateral tooral sucker, cylindrical, 40- 60 X 20-30!l;esophagus very narrow, 0.3-0.65 mm long. Cecawith short branches, terminating separately atbase of opisthohaptor.

Testes rounded , up to 25 in number (mostly16) , arranged in a zigzag longitudinal row,occupying greater part of postovarian inter ­intestinal field. Vas deferens may be stronglyswollen in preovarian interintestinal field.Cirrus plug-shaped, muscular, covered insidewith spinules, 50- 90 X 27-50!l, with two un­equal sclerotized filaments at base; anteriorfilament 50- 120!l long, usually widened distally,posterior hook-shaped, 35-60!l long, both oftenappressed against cirrus. Genital pore ventro­median, 0.06-0.22 mm posterior to pharynx.

Ovary turned back on itself five times, form ­ing N-shaped loop posteriorly and double loopanteriorly, situated in anterior part of middleth ird of body. The germiduct runnin g forwardgives off the genito-intestinal duct near itsorigin and soon unites with the descendingvitelline stem. Uterus largely ventromedian ;eggs elliptical, 110-130 X 50-75!l' with long,very fine filament at antiopercular pole. Vitel­laria coextensive with intestinal limbs; vitellinereservoir Y-shaped, with long, sometimes short ,stem, and rather short arms, coinciding withovary. Vagina well cuticularized, with wide mid-

,s.;

58

0"y J)

j 5c

~

N ew Monogenetic Trematodes, II-Y AMAGUTI

dorsal opening 0.1-0.35 mm posterior to gen­ital pore, usually anterio r to anterior end ofvitellaria, but sometimes much posterior to thislevel. Vaginal duct inverted Y-shaped, eachbranch opening into arm of vitelline reservoirof its own side.

DISCUSSION : This genus bears a superficialresemblance to Pterinotrema Caballero, Bravo­Hollis, and Grocott, 1954, but differs from itfundamentally in the structure of the clampsand the terminal geni talia, and in possessinga typical oral sucker and a pharynx. I prefer toseparate it as representing a new genus, forwhich the nam e Pseudopterinotrema is sug­gested, with the following diagnosis.

Pseudopteriuotr ema n. g.

GENERIC DIAGN OSIS: Pterinotrematidae. Bodysmall, cylindrical. Prohaptor circular, with adorsal conical papilla. Opisthohaptor with ninelong-stalked clamps, one of which, to the ex­treme right in the type, bears an armed caudalappend age. Each clamp, except for two extremeright ones, with two axial sclerites fringed withspines on its stalk, and two terminal clampvalves which are also fringed with spinelets. Atransverse row of six small, two-valved suckerspresent at base of third to seventh clamp stalks,extreme left one to left of base of ninth sclerite.At base of fourth clamp is a rod -shaped lobebearing two pairs of very small larval hooklets.Oral sucker and pharynx present. Intestinallimbs with short oute r branches , terminatingseparately at base of opisthohaptor. A numberof rounded testes in a zigzag longitud inal rowin posterior interintestinal field. Copu latory or­gan consisting of plug-shaped , muscular, spinedcirrus and two accessory sclerit es. Genital poreventromedian, immediately behin d prohap tor.Ovary tubular, looped, pretesticular. Vaginasclerotized, opening middorsally near intestinalbifurcation ; vaginal duct inverted Y-shaped ,each branch connected with arm of vitellinereservoir of its own side. Eggs elliptical, fila­mented at antiopercular pole. Vitellaria coex­tensive with intestine. Gill parasites of marineteleosts.

TY PE SPECIES: P. albttlae n. sp., on A lbul«oulpes; H awaii.

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6. Slbitrema poonui n. g., n. sp.Fig. 6

H ABITAT : Gills of Parathennus sibi (localname "poonui" ); H awaii.

H OLOTYP E: U. S. N at. Mus. Helm. CoIl.,S. Y. N o. 50.

DESCRIPTION (based on a single gravid speci­men) : Body 19.2 mm in total length, distinctlydivided into three regions: body proper, hap­toral stalk, and haptoral region. Body properslender, lanceolate, tapered anteriorly, with apair of compact eyespots, constricted behind,11.7 mm long, 1.4 mm wide in posterior partwhere the ovary is situated; haptoral stalk fusi­form, 4.3 X 0.45 mm, containing intestine andvitelline gland alone, attenuated posteriorly andthen gradually enlarged to pass into haptoralregion which is spatulate, produced posteriorlyinto a conical terminal appendage. This appen­dage is 0.2 mm long, 0.2 mm wide at the base,and bears on the ventral sur face of its apextwo pairs of larval hooklets of different size;outer pair 46ft long, inner pair 21ft long, bothwith a very prominent guard and a well curvedblade. On the left border of the haptoral reg ionis a single longitudinal row (a bout 3 mm long)of 48 clamps 50-90ft in transverse diameter.Clamp skeleton consisting of a pair of innerbasal processes, two pairs of lateral arms, a pairof accessory pieces meeting in median line, anda stout median sprin g, one end of which isanchor -shaped , while the other end is sur­mounted by a Y-shaped apical piece. Mouthcavity wide, opening ventroterminally, with ovalpaired suckers (46 X 23ft) laterally and aglobular, weakly muscular, median pharynx atits bottom ; esophagus simple, 1.45 mm long,contra cted at beginning, but soon enlarged towidth of 0.15 mm, bifurcating immediately be­hind genital pore. Intestinal limbs with numer­ous short inner and longer outer branches;right limb terminating at base of terminalappendage, left one 0.5 mm farther in fr ont.

Testes rounded, 75 in total number, pre-,para-, and postovarian ; preovarian testes in twoparallel submedian rows of 15 or 16 each; para­ovarian testes 18 or 19, in two longitudinal rowsimmediately outside ovarian loop ; behind theovary there are only several testes in the medianfield. Vas deferens median, dorsal to uterus ;

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6F

GA

PACIFIC SCIENCE, Vol. XX , October 1966

p

FIG. 6. Sibitrema poonui n. g., n. sp. 6A , Hol otype, ventral view; 68 and 6C, enlarged anterior and posteriorregions of holotype, ventral view ; 6D, clamp ; 6E, anchors on caudal appendage of holotype; 6F, terminalgenitalia of paratype, dorsal view ; 6G, egg.

N ew Monogenetic Trematodes, II-YAM AGUTI

bulbus cirri weakly muscular, 70f! in diameter,situated just ventral to intestinal bifurcation.Cirrus consisting of several sharp-pointed spineswhich are 35f! long and bundled together im­mediately in front of atrial crown of 12 spines ;these spines are 51-56f! in length including basewhich forms a ring of 12 backwardly directedprongs; the shaft of each spine is straight, butthe apex is curved inward and bifid at the tip .This crown of spines is enclosed in a very thick­walled atrial bulb of radial muscle fibers, whichin turn is enclosed in a membranous genitalatrium . Genital pore midventra l, at anteriorend of genital atrium, 1.45 mm from head end.

Ovary tubular, bent back on itself on rightside of median line, 3.15 rom long as a whole,swollen ( 0.3 mm wide) at postequatorial proxi ­mal end in form of a recurved mass and at distalend in form of a club, from the posterior end ofwhich the germiduct arises. Genito-intestinalcanal arising from near middle of germiduct,runnin g obliquely forward across proximal por­tion of ovary ventrally to empty into right intes­tinal limb. Vitelline follicles small, coextensivewith intestinal branches, commencing a littlebehind vaginae; vitelline reservoir Y-shaped, toleft of distal end of ovary, connected withgermiduct by a narrow descending median stem0.15 mm long. Uterus sraight , midventral, con­taining a few eggs; eggs fusiform, 0.23-0.25X 0.07-0.09 mm, with filament 40-60f! longat each pole. Vaginae symmetrical, about 0.5mm long, divided into a series of several (8­14 ) areolae, situated laterally about halfwaybetween genital pore and anterior end of vitel­laria.

DISCUSSION: This genus closely resemblesAllopsendaxine Yamagut i, 1943, in intern alanatomy, but differs markedly in general bodyshape and, what is more important, in thestructure of the clamp. On the basis of the latterdifference I prefer to propose the new subfamilySibitrematinae for its reception, with the follow­ing diagnosis.

Sibitrematinae n. subf.

SU BFA MILY DIAGNOSIS : Axinidae. Bodydivided into three distinct regions. Opisthohap­tor asymmetrical, without prehaptoral larval

431

anchors. Clamp skeleton consisting of two pairsof lateral sclerites, one pair of basal innersclerites, an arcuate median spring, and a pairof accessory sclerites. A terminal lappet bearinglarval hooklets present. Testes numerous, pre-,para-, and postovarian. Ovary inverted U­shaped. Vaginae double, symmetrical.

Slbltrema n. g.

GENERIC DIAGNOSIS : Axinid ae, Sibitremati­nae. Body long, divided into three distinctregions: body prop er, haptoral stalk, and opis­thohaptor with a row of numerous clamps uni­laterally and a terminal lappet bearing two pairsof anchors. Paired oral suckers poorly devel­oped. Esophagus bifurcating near genital pore.Intestinal limbs with numerous side branches,terminating blindly near base of terminal lappet.Testes numerous, pre-, para-, and postovarian .Genital atrium membranous, immediately pre­bifur cal, enclosing atrial bulb of radial musclefibers at bottom, latter in turn provided insidewith a crown of spines, beyond which thebundl ed cirrus spines project forward. Ovarytubular, bent back on itself in middle th ird ofbody. Genito-intestinal canal crossing proximalportion of ovary. Eggs with filament at eachpole. Vitellaria coextensive with intestinalbranches ; vitelline reservoir Y-shaped, in ovar­ian region. Vaginae divided into a series ofseveral areolae, situated about halfway betweengenital pore and anterior end of vitellaria. Gillparasites of marine teleosts.

TYPE SPECIES: S. poonni n. sp., on Paratbun­Il/IJ sibi; Hawaii.

7. Cypselurobranchitre11la spilonotopterin. g., n. sp.

Fig. 7

HA BITAT: Gills of Cypselurus spilon otop­terns; H awaii.

HOLOTYPE: U. S. Nat. Mus. Helm. ColI.,S. Y. No. 51.

DESCRIPTION (based on four whole mounts) :Body 7- 10 mm in total length , enlarged later­ally up to 2.5-3.5 mm wide in midregion:anterior third abruptly tapered toward head endwhich is 0.2-0.4 mm wide at the level of theoral suckers ; posterior third occupied by large

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7c

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II

IIII

FIG. 7. Cypselnrobrancbitrem« spilonotopteri n. g ., n. sp . 7A , Holotype, ventra l view ; 7B, clamp ; 7C, an­chors on caud al appendage of holotype (1) and two par atypes (II and III) ; 7D, anterior extr emity of para­type, ventral view ; 7E, terminal gen itali a of para type, ventral view; 7F, mature eggs from paratype.

N ew Monogenetic Tr ematodes, II-YAMAGUTI

cotylophore which is 2.4-4.2 mm long by 2.8­3.8 mm wide and extends on the ventral sidefrom behind the posterior end of the ovary toa considerable distance back of the posteriorend of the body proper . In the type this cotylo­phore begins in the midventral region at thelevel of the junction of the middl e with theposterior third of the entir e body with a smoothsemicircular fold 1.2 mm wide which is fol­lowed by a twisted, fan-shaped body foldfringed with a semicircular row of 18 or 19long-stalked clamps. For convenience of refer­ence the clamps are numbe red from in frontbackwards; the first clamp next to the semi­circular fold is the smallest ( about 0.2 mm indiameter) , rather short-stalked, the 12th maybe slightly out of the row of other clamps, the14th to 16th are the largest (up to 0.45 mm indiameter), with longer stalks, and the last 18th(19th in one paratype) attached to the rightposterior end of the body proper is provided onthe proximal anterior margin of its stalk witha blunt-conical or subcylindrica l caudal appen ­dage 0.15-0.16 mm long. This caudal appen­dage is armed in the type with a small guardedapical hook 35ft long and two dissimilar sub­apical hooks, one of which is 77ft long andguarded like the apical hook, but the other issimple, falcate and 37ft long lineally. In theparatypes either the guarded subapical or thefalcate hook is absent (see Fig. 7C), so that thearmature of this appendage is variable. Clampskeleton 0.18-0.46 mm in diameter, consistingof an arcuate, perfo rated, median spring, andtwo pairs of curved lateral arms articulatingwith each oth er, of which the smaller pairarticulates at the distal end with a small A­shaped accessory sclerite.

H ead end rounded; mouth aper ture wide,subterminal; oral suckers paired, muscular, sep­tate, 53-81 X 65-93ft; pharynx oval, weaklymuscular, 116 X 98ft in the type. Esophagussimple, 0.5-0.7 mm long, bifurcating a littlebehind genital pore. It is not certain whetherthe intestinal limbs are confluent posteriorly ornot ; there are wide anterolaterally directeddiverticles on each side anteriorly ( Fig. 7D) ,the remaining greater part with few short inner,and numerous longer, subdivided, outerbranches accompanied by vitellaria and pigment

433

cells; posterior outer branches extending intobasal portion of clamp stalks.

Testes rounded, about so in total numb er,arranged in two zigzag longitudinal rows, oneon each side of median line; anterio r ones pre­ovarian, posterior ones para-ovarian, some be­tween ovarian limbs. Vas defer ens straight orgently undul ating in median field, surroundedat its distal end by prostate cells; no pars pro­statica different iated. A distinct globular bulbof very fine muscle fibers is developed aroundthe somewhat swollen distal end of the ejacula.tory duct. Cirrus represented by a cylindricalgroup of very fine acicular spines, enclosedbasally in a crown of 18 hooks, which in turnis enclosed in the atrial bulb with thick wallsof radial muscle fibers. The hooks are fusednear the base, and their simple attenuatedpoints are curved inwards. This thick-walledatrial bulb is 5I- 80ft in outside diameter, andenclosed entire ly in the genital atrium with amembranous wall. Genital pore midventral,immediately in front of the above mentionedthick-walled atrial bulb, 0.5-0.7 mm from headend.

Ovary inverted U-shaped, 2.35 mm long by0.4 mm wide as a whole in the type, enlargedat proxi mal end to an elongate compact mass,situated to righ t of median line in middl e th irdof body. Genito-intestinal duct arising fromgerm iduct just befor e the latter unites with thestem of the vitelline reservoir. Ootype postero­sinistral to th is genital junction. Uterus properalongside vas deferens, opening into genitalatrium ventral to male duct. Mature eggs elon­gate oval, 0.25- 0:26 X 0.11-0.1 5 mm, with arigid filament at each pole; anterior filament0.19-0.26 mm long, posterior filament 0.12­0.2 mm long, slightly enlarged at tip. Genito­intestinal duct running straight obliquely for­ward and emptying into right intestinal limb,with distinct accompanying cells. Vaginae in­distinct in the type, but present on each side inform of a ventrosubmarginal longitudinal rowof several rud imentary areolae just behind levelof symmetrical excretory pores in one of theparatypes. Vitelline reservoir Y-shaped, withshort arms. Excretory pores symmetrical, dorsal,submarginal at about level of genita l pore or alittle posterior to it.

434

DISCUSSION: This genus is very closely re­lated to Allopseudaxinoides Yamaguti, 1965,2in general internal anatomy, but differs fromit in the arrangement of clamps and in posses­sing septate oral suckers but no reticular anas­tomosis of the anteriormost vitelline ducts.On the basis of these differences I prefer tocreate the new genus Cypselurobrancbitrema,for which a new subfamily Cypselurobranchi­trematinae is suggested, because this genus can­not be assigned to Allopseudaxininae Yamaguti,1963.

Cypselurobranchitrematinae n. subfam.

SUBFAMILY DIAGNOSIS: Axinid ae. Body elon­gate, moderately wide. Op isthohaptor twistedfan-shaped, attached on ventral side of bodyproper at its posterior end, frin ged with anumb er of stalked clamps in semicircular row.Oral suckers paired, septate, within oral cavity.Intestine strongly ramified. Testes num erous,pre- and paraovari an. Genital atrium enclosingarmature of complex structure, open ing mid­ventrally. Ovary tubul ar, in midregion of body.Genito-intestinal duct present. Eggs filamented.Paired vaginae rud imentary or absent. Vitellariacoextensive with intestine and its branches. Gillparasites of marine fishes.

Cypselurobranchitrema n. g.

GENERIC DIAGNOSIS : Axinidae, Cypseluro­branchitrematinae. Body moderately large,abruptly tapered anteriorly. Op isthohaptorasymmetrical, arising from posterior midventralregion of body proper, with a twisted semi­circular body fold , which is followed by afan-shaped fold fringed with a semicircularrow of a number of stalked clamps; clampskeleton similar to that of Allopseudaxin oidesYamaguti , 1965. Caudal appendage with an­chors of different shape and size on stalk oflast clamp. Intestinal limbs with short innerand longer outer branches. Testes small, ar­ranged in two longitudinal rows, pre- and para-

2 Th e origi nal diagnosis of this genus is emendedas follows: "Vaginae rud imentary, opening dorso­subma rginally at about level of genit al pore or absent.Anteriormost vitell ine ducts of two sides with reticu­lar anastomosis ."

PACIFIC SCIENCE, Vol. XX, October 1966

ovarian . Prostate cells around distal end of vasdeferens; ejaculatory duct enclosed in musclebulb. Cirrus represented by a cylinder of veryfine acicular spines, surrounded basally by aring of hooks, which in turn is enclosed inatrial bulb with thick walls of radial musclefibers. Genital atrium opening ventral to esoph­agus. Ovary inverted U-shaped, submedian,in midregion of body. Gen ito-intestinal ductopening into right intestin al limb. Eggs withrigid filament at each pole. Vitelline folliclessmall, largely coextensive with intestine andits branches, with which they extend into thestalk of clamps. Vagin ae ind istinct or openingsymmetrically on ventral submarginal surfacea little behind level of genital pore . Parasitic ongills of marine teleosts.

TYPE SPECIES : C. spilonotopteri n. sp., onCypselem s spilonotopterus; Hawaii.

REFERENCES

CABALLERO Y C. E., M. BRAVO HOLLIS, andR. G. GROCOTT. 1954. Helmintos de laRepublica de Panama. XII. Descripcion dedos nuevos trematodes monogeneos, parasitesde peces marinos comestibles del OceanoPacifico del Norte. Ciencia, Mexico 14(4-6) :81-86.

JOHNSTON, T . H. 1931. N ew trematodes fromthe subantarctic and antarctic. Australian J.Exp. BioI. Med . Sci. 8: 91- 98.

TRIPATHI, Y. R. 1959. Monogenetic trematodesfrom fishes of Indi a. Indian J. Helminthol.9(1-2) :1-149.

UNNITHAN, R. V. 1962. On the functionalmorphology of a new fauna of Monogenoid eaon fishes from Trivandrum and environ s.Part II. Opi sthogynidae fam. nov. (Gastro­cotyloidea) and Abortipedinae subf. nov.(Protomicrocotyloidea) . Parasitology 52:315-351.

YAMAGUTI, S. 1943. Verzeichnis der ektopara­sitischen Trematoden der japanischen Fische.Published by author. 3 pp.

- -- 1963. Systema Helminthum, Vol. IV.Monogenea and Aspidocotylea. Interscien cePublishers, New York. 699 pp.

--- 1965. New monogenetic trematodesfrom Hawaiian fishes, I. Pacific Sci. 19(1):55-95 .