New Monogenetic Trematodes from Hawaiian , IP SATYU YAMAGUTI

IN THIS SECOND REPORT are described seven III. Pterinotrematidae Bychowsky and Nagi­ new of monogenetic trematodes belong­ bina, 1959 ing to six new genera, two of which represent 5. Pseudopterinotrema albulae n. g., n. sp. each a new subfamily. One of these two species seems to occur rather uncommonly on the IV. Axinidae Unnithan, 1957 Hawaiian flying fishes; so far I have managed Sibitrematinae n. subfam. to collect only four specimens after a long 6. Sibitrema poonui n. g., n. sp. search. Although the host of this worm is a Cypselurobranchitrematinae n. subfam. pelagic , its parasite fauna seems rather 7. Cypselurobranchitrema spilonotopteri endemic in character, inasmuch as the mono­ n. g., n. sp. genetic and digenetic trematodes found on or in the Hawaiian flying fishes are quite different 1. Pseudallobenedenia apharei n. gen., n. sp. from those occurring in the allied host species Fig. 1 in the neighboring waters. This fact strongly HABITAT: Gills of Aphareus rutilans ; Hawaii. suggests that the distribution of the Hawaiian flying fishes is not very extensive. HOLOTYPE : U. S. Nat. Mus. H elm . ColI., All the other new genera of to S. Y. No. 45 . be reported by me from Hawaii will be de­ DESCRIPTION (based on 21 whole mounts): scribed in a monograph upon Hawaiian mono­ Body approximately fusiform, 2.6-5.3 mm genetic trematodes, so that the present report long, with maximum width of 0.7-1.9 mm at is the last of the series for new Hawaiian mono­ about testicular level. Posterior extremity of genetic genera to be described in short articles . body proper attenuated to a flap covering opis­ Thanks are due to all the institutions and thohaptor dorsally. Opisthohaptor discoid, usu­ persons concerned in my survey of Hawaiian ally projecting a little beyond posterior end of trematodes, including the National Science body proper, 0.43-0.8 mm longitudinally ex­ Foundation, the University of Hawaii, myassis­ cept for scalloped marginal membrane 20-80~l tant, Mr . Shunya Kamegai, and my wife, Ikuko wide, with a central pit 0.1-0.15 mm in diame­ Yamaguti. ter; on the concave ventral surface there are The new species described herein are assigned three pairs of anchors, but no definite septa or to the following families and subfamilies: ridges, although several symmetrical radiating excretory vessels are seen bifurcating or not at I. Baird, 1853 their submarginal ends ; anterior anchor 28-37~ Benedeniinae Johnston, 1931 long from tip to posterior end , situated postero­ 1. Pseudaliobenedenia apharei n. g., n. sp. lateral to central pit; two posterior anchors 2. Psendallobeneden in opakapaka n. sp. close together near posterolateral edge of opis­ 3. Lageniuaginopseudobenedenia etelis n. thohaptor; longer J-shaped medial one slender, g., n. sp. 18-33~ long ; shorter lateral one hook-shaped, with bifid root, 14-21~ long. Prohaptors ellip­ II. Discocotylidae Price, 1936 tical, saucer-shaped, 0.54-1.0 X 0.24-0.48 mm , Opisthogyninae Unnithan, 1962 connected dorsally by medianly incised frontal 4. Metopisthogyne sphyraenae n. g., n. sp. plate which never projects forward beyond the prohaptors. Mouth opening ventrally at level 1 Contribution No . 248 from Hawaii Institute of of posterior end of prohaptors, with one pair or Marine Biolog y. Un iversity of Hawaii, supported by a grant (GB-2992) from the National Science two of eyespots dorsally. Pharynx muscular, in­ Foundation. Manuscript received May 3, 1965. cised anteriorly into five lobes, more or less 419 4 20 PACIFIC SCIENCE, Vol. XX, October 19 66

ABBREVIATIONS USED IN FIGURES AB atrial bulb GI genito-intestinal canal PH proh aptor AG apical gland GO Goto's organ PM pars muscul aris AP accessory piece GP genital pore PR pros tatic reservoir AS axial sclerite HC head cone RS receptaculum seminis BC bulbus cirr i I intestine S sucker BE bulbus ejaculatorius IE intestinal branch SG shell gland C cirrus ID intestinal divertide T testis CA caudal appe ndage LL larval lappet TG termin al genitalia CL clamp M mouth U uterus CP cirrus pouch 0 ovary V vagina CS crown of spines OC eyespot VD vas deferens CV d amp valve OH opisthohaptor VGD vaginal duct DE ductus ejaculatorius OS oral sucker VP vaginal pore E egg P pharynx VR vitelline reservoi r ES esophagus PC pros tatic cell VT vitelline gland GA genital atriu m PD prostatic duct VTD vitelline duct constricted laterally near broadly rounded pos­ and more or less convoluted prostatic duct; both terior end, 0.22- 0.52 X 0.24-0.65 mm. Esoph­ ducts joining together to form cirrus which is agus short ; each intestinal limb giving off more enclosed throughout its length in the thin­ or less dendritic outer branches, of which the walled, tubul ar, genital atrium, and may or may anterior pair extends into the frontal plate, not project out of the genital pore. The genital almost meeting in the median line; posterior­ atrium is continued from the wall of the cirrus most pair sends out several outer branches pouch with the same diameter as the latter, but reaching lateral edges of body and a few tapers into a very long, narrow tubul e which shorter inner branches probably anastomosing runs backward and then curves toward the left each other ; no anastomosis between two main in front of the transverse vitelline duct; it turns intestinal limbs posteriorly. back on itself here to follow the same course as Testes oval to elliptical, 0. 28-0.8 X 0.18-0.5 its proximal portion , and after passing beside mm, directly juxtaposed, largely in posterior the cirrus pouch proceeds straight obliquely for­ part of middle third of body, with paired mul­ ward to open ventrosublaterally at the level of tinucleate Goto's glands immediately behind. the posterior end of the pharynx on the left Vas deferens running forward along left mar­ side. gin of ovary, convoluted just medial to left in­ Ovary subglobular, 0.08-0.28 X 0.1- 0.25 testinal limb, then crossing uterus dorsally and mm, situated medianly between anterior ends coming to right side of median line, where it of testes. Germiduct arising from anterior end enters the cirrus pouch along with the prostatic of ovary, joining duct from vitelline reservoir reservoir and finally unites with the prostatic and leading into ootype which passes into a duct to lead into extremely long ( 2-3 mm or long, winding, muscular uterine duct. Ut erus more) spicular cirrus. Prostatic cells massed proper forming diverticle-like expansion when around distal portion of vas deferens and pro­ distended with eggs ; distal portion of uterus static reservoir which is elliptical, 0.1 mm long proper runn ing obliquely forward along with by 0.05 mm wide in the type and lies longitu­ genital atrium, opening together with latter by dinally alongside the vas defer ens. Cirrus pouch a common pore. Shell gland cells developed somewhat muscular, small (exact length not around ootype. Eggs mostly rounded conical, determin able) , containing windin g vas deferens but rounded triangular in flattened condition,

FIG. 1. Pseudallobenedenia apbarei n. g., n. sp. I A, Holotype, ventral view; 1B, haptoral anchors of paratype; l C, terminal genitalia of paratype, ventral view. FIG. 2. Pseudallobenedenia opakapaka n. sp. 2A, Holotype, ventra l view ; 2B, haptoral anchors; 2C, ter­ minal genita lia, ventral view. New Monogenetic Trematodes, II-YAMAGUTI 421

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28 422 PACIFIC SCIENCE, Vol. XX, October 1966

with extremely long, very fine, antipolar fila­ is much longer, often convoluted, and contains ment at base, 0.1-0.125 X 0.09-0.11 5 mm as an extremely long cirrus. The unusually long measured in life and in lactophen olglycerin and wide uterus in P. apbarei is worth notin g. jelly. Vitelline follicles extend ing in lateral fields from level of posterior part or end of 2. Pseudallobenedenia opakapaka n. sp. ph arynx to base of posterior flap covering opis­ Fig. 2 thohaptor, confluent in median line between HABITAT: Gills of Pristipomoides microiepis testes and opisthohaptor, intruding into small (local name "opakapaka" ) ; Hawaii. area between transverse vitelline ducts and testes ; transverse vitelline ducts united rnedi­ HOLOTYPE: U. S. N at. Mus. H elm. ColI., anly, forming inconspicuous vitelline reservoir S. Y. N o. 46. only 20- 110/-l anteroposteriorly. Vagina open­ DESCRIPTION ( based on thr ee whole mounts) : ing ventral to uterus by a very small pore a Body elongate, distinctly constricted immediately little behind intestinal bifurcation; vaginal duct behind prohaptor, 3.0-5.5 mm in total length winding along with vas deferens medial to left including opisthohaptor, with maximum width intestinal limb ; receptaculum seminis vaginae of 0. 1-0.15 mm at level of testes. Opisthohap­ oval, 50-150 X 30-110/-l, lying between left tor bell-shaped, 0.6- 0.8 mm in transverse di­ transverse vitelline duct and ootype; seminal ameter, provided with a scalloped marginal duct connectin g seminal receptacle with vitel­ membrane. There are three submedian pairs of line reservoir very short. Excretory vesicle fun­ weakly developed anchors on the inner surface nel-shaped, symmetrical, opening dorsally at of the posterior half of the opisthohaptor; an­ level of intestinal bifurcation. terior anchor rod-shaped, 40-50/-l long, middle DISCUSSION: This genus very closely resem­ and posterior anchors a little apart from the an­ bles Allobenedenia Yamaguti , 1963 in gross terior, close together near haptoral margin; anatomy, but differs in minor details as shown middle one somewhat undulating, barbed dis­ in Table l. tally, 40-43/-l long; posterior one hook-shaped, 18-25/-l long. Prohaptor oval, saucer-shaped, The present species differs from P. opakapaka glandular, 0.21-0.28 mm long; between the to be described below in that the genital atrium two is seen the trun cate head end level with the anterior end of the . Two pairs TABLE 1 of eyespots anterodorsal to pharynx. Pharynx subglobular, without constriction, 42-58 X 52­ DIFFERENTIATI ON OF Pseudallobenedenia FROM Allobenedenia 62/-l. Esophagus very short, surrounded on each side by postpharyngeal cells, whose ducts ap­

CHARACTER Allobenedenia Pseudallobenedenia pear to open into the ph aryngeal lumen close to its posterior end. Int estinal limbs with com­ Front al hood present absent paratively long, subdivided, outer branches, ter­ Cirrus long extremely minating separately a short distance away from long posterior end of body. Genital atrium not extremely extremely Testes elliptical, juxtaposed at anterior part long long, convoluted of middle third of body, 0.3 7-0.7 X 0.17-0.28 or straight mm, with paired Goto's glands immediately be­ Vaginal marginal submedian, hind. Multinucleate organs like Goto's were opening or sub­ postbifurcal found immediately in fron t of the testes and marginal, beside ovary. Vas deferens convoluted between prebifurcal left intestinal limb and shell gland complex, Receptaculum absent well then forming a very long horseshoe-shaped loop seminis developed across uterus and cirrus pouch dorsally, pene­ Vitelline saccular, no definite trating cirrus pouch at its anterior base, finally reservoir very reservoir joining prostatic duct at posterior end of cirrus distinct pouch. Cirrus pouch cylindrical, 0.2- 0.7 mm New Monogenetic Trematodes, 1I-Y AMA GUTI 423

long, arcuate, strongly muscular, swollen at its median, level with posterio r end of pharynx or forwardly directed base, situated longitudinally farther behind . Ovary immediately pretesticular. between right intestin al limb and uterus, con­ Eggs rounded conical or pyramidal, with very taining prostatic duct and vas deferens, both of long filament at base or basal corner. Vitellaria which are straight, narrow, and close together, extensive; vitelline reservoir inconspicuous. Va­ though convoluted at the anterior base of the gina opening submedianly ventral to uterus at cirrus pouch. Cirrus spicular, long, enclosed in postbifurcal level ; receptaculum seminis vagi­ sheathlike genital atrium which extends from nae well developed. Gill parasites of marine the posterior distal end of the cirrus pouch to . the genital pore along the dorsal side of the T YP E SPECIES : P. apharei n. sp., on Apbar­ cirrus pouch. This overlapping portion is shown eus rutilans; H awaii. separately in the figure. Prostatic reservoir OTHER SPECIES : P. opakapaka n. sp., on Pris­ elongate, 80-90 X 100-130/-l., situated imme­ tipomoides microlepis; H awaii. diately in front of base of cirrus pouch. Genital pore common, just posterosinistral to pharynx. Ovary subglobular, 0.17-0.27 X 0.17-0.22 3. Lagenivaginopseudobenedenia etelis mm, situated between two testes and vitelline n. g., n. sp. reservoir. Shell gland complex strongly devel­ Fig. 3 oped. Uterus distended with eggs. Eggs rounded HABITAT: Gills of Etelis carbtl1lculus (local pyramidal, with triangular base in balsam name "onaga" ) ; Hawaii. mounts, 0.12-0.14 X 0.12-0.1 5 mm in life , with very fine, long filament at one basal cor­ H OL OTY PE : U. S. Nat. Mus. Helm. ColI., ner. Vagina opening ventrally in left submedian S. Y. N o. 47 . line a little posterior to intestina l bifurcation; DESCRIPTION (based on three whole mounts): vaginal duct thick-walled , running straight Body elliptical, flat, 2.9-4.3 mm in total length , backward and opening into oval seminal recep­ 1.8-2.3 mm wide in midregion; head and neck tacle which measures 1OO~l by 80/-l. in the type. region contracted and well separated from Vitella ria coextensive with intestinal limbs and trunk. Opisthohaptor elliptical, 0.53-0.75 mm their branches; vitelline reservoir transversely long, with finely scalloped marginal membrane elongated, not forming a compact mass, 60-90/-l. 30-70/-l. wide and three pairs of anchors ; num­ anteroposteriorly. Paired excretory vesicles con­ ber of marginal hooklets not determined; ante­ spicuous at level of uterus. rior anchor 0.13-0.17 mm long, sharp -pointed DISCU SSION: The differences between this anteriorly, nonalate, with two small blunt species and the type species are given in the stumpy processes of unequa l length at posterior discussion of the type species. end ; midd le and posterior anchors definitely smaller than anterior ; middle one slender, 50­ 80/-l. long, with undulating root and minute Pseudallobenedenia n. gen. terminal claw ; posterior one enlarged and flat­ GE N EIUC DIAGNOSIS: Capsalidae, Benedenii­ tened from side to side basally, 30-40/-l. long, nae. Opisthohaptor discoid, not septate, with terminating in a minute claw. Prohaptors saucer­ scalloped margina l membrane, armed with three shaped , paired, close together, 0.19-0.23 X pairs of anchors. Prohaptors not enclosed in 0.36-0.42 mm, containing glandular tissue hoodlike frontal plate. Pharynx muscular, lobed which extends not only backward but also in­ anteriorly; intestinal limbs branched, not con­ ward to be confluent in the median line pos­ fluent posteriorly, though their posterior inner terior to somewhat incised frontal margin. Two branches may anastomose. Testes juxtaposed ; pairs of eyespots present anterodorsa l to phar­ vas deferens convoluted medial to left intestinal ynx. Pharynx spherical, 0.27-0.29 X 0.3-0.31 limb. Prostatic cells and reservoir outside cirrus mm, glandular rather than muscular, papi llate pouch. Cirrus pouch long; cirrus extremely internally. Esophagus practically absent; ceca long, enclosed in extremely long, tubular, genital with numerous dendritic outer branches, not atrium . Genital pore common, sublateral or sub- confluent posteriorly. 424 PACIFIC SCIENCE , Vol. XX, October 1966

it penetrates from the dorsal side ; after enter­ ing the cirrus pouch it pursues a short winding course, then a long straight course alongside the distal portion of the prostatic duct, with which it 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 behind pharynx, containing at its base a small, tubular, prostatic reservoir and cylindrical pars muscu­ laris of prostatic duct which is 0.1-0.13 mm

VTn long and provided with a thick coat (30 -6011 wide) of fine circular muscle fibers. Prostatic T cells distributed around base of cirrus pouch . Cirrus elongate conical, pointed, 0.42 X 0.06 mm in the type ; it mayor may not project out of the genital pore. Common genital pore pos­ terosinistral to pharynx, a little (0.1 mm in the IB type) away from nearly right angle formed by neck and trunk. Ovary subglobular to oval, 0.15-0.3 X 0.09­ 0.22 mm, situated medianly, with its posterior end intercalated between two testes. Ootype spherical, 0.15 -0.2 rom in diameter, provided with epithelial lining ; uterus proper well sepa­ rated from ootype, 0.2 mm wide in the type, openin g into common genital pore by a funnel­ 38 shaped passage. No eggs observed. Vitellari a consisting of small follicles, coextensive with intestine, wide apart anteriorly, but confluent posteriorly ; paired longitudinal collecting ducts distended with yolk cells; transverse duct may be narrower, up to 7011 wide in the larger para­ type, not forming a definite reservoir. Vagina lageniform, 0.17 mm wide in the type, muscular at its narrow neck, situated between uterus and right intestinal limb, opening almost rnidven­ trally behind cirrus pouch. Seminal receptacle oval, 0.1 X 0.055 mm in the type, between c vagina and vitelline reservoir. Excretory system not made out. DISCUSSION: This genus, characterized by the FIG. 3. Lagenivaginopseudobenedenia etelis n , g., n. sp. 3A , Holotype, ventral view ; 3B, haptoral an­ head and neck being marked off from the trunk chors of holotype; 3C, term inal genitalia of holotype, and by the peculiar structure and position of the ventral view. vagina, bears a certain resemblance to Pseudo­ benedenia Johnston, 1931, especially in the pro­ Testes elliptical, 0.31-0.5 X 0.2-0.34 mm, static vesicle being enclosed in the cirrus pouch, juxtaposed contiguously at anterior part of mid­ but it seems justified to separate the genus in dle third of body. Rudimentary Goto's organ question from Pseudobenedenia on the basis of present. Vas deferens convoluted immediately the above mentioned features. The compound anterosinistral to vitelline reservoir, then wind­ generic name refers to the lageniform vagina ing along posterior wall of cirrus pouch, which and close relationship to Pseudobenedenia. N ew Monogenetic Trematodes, II-YAM AGUTI 42 5

Lag eniuaginopseudobenedenla n. g. of median spri ng with three or four minute holes, enlarged at apex in form of a trian gle; GENERIC DIAGNOS IS: Capsalidae, Benedenii­ other prong-with anchor-shaped apex, may be nae.Prohaptors consisting of paired glandu lar bulbously swollen near its base. Of the caudal saucers placed close together. Op isthohaptor hooks the larger outermost is 41-46[! long from discoid, aseptate, with scalloped marginal mem­ tip of root to height of curve of blade, and has brane, armed with three pairs of anchors. Eye­ a curved guard a little shorter than root ; the spots pr esent. H ead and neck region much nar­ smallest middl e is 16-18[! long and has a com­ rower than trunk and well marked off from it. paratively long root and a short curved blade ; Pharynx sph erical, without constriction, rather the innermost is somewhat similar in shape to glandular, papillate internally. Intestinal limbs the outermost and 25-28[! long. H ead rounded with dendritic outer branches, not confluent in fr ont, 0.16-0.32 mm wide, with ventral posteriorl y. Testes juxtaposed, entire. Vas def­ mouth aperture and a pair of groups of gland erens strongly convoluted in fron t of left trans­ ducts at apex ; paired oral suckers aseptate, mus­ verse vitelline duct, passing transversely beh ind cular , 70-93 X 58-72 ~ , close together, fol ­ cirrus pouch and penetrating it near its base. lowed by ovoid nonm uscular pharynx 51-70[! Cirrus pouch cylindrical, extending transversely long by 48-58[! wide; esophagus 1.0-2.0 mm behind pharyn x, containing small prostatic res­ long, simple, wide, bifurcating just in front of ervoir and well develope d pars muscularis of vaginal pore ; intestinal limbs with shor t side prostatic duct at its base. Cirrus elongate coni­ branches, terminating separately, one at base of cal, pointed, pro jecting into thin-walled genital opisthohaptor and the other a little more pos­ atrium. Common genital pore ventrosubmedian, teriorly. well apar t fro m body margin. Ovary entire, not Testes small, ovoid, 93-162 in total number, separated from testes by vitellar ia. Vitellaria co­ extending in interintestinal field from ant erior extensive with intestine; no definite vitelline part of middle third of body to anterior half of reservoir . Vagina lageniform, between uterus caudal third, mostly preovarian, partly para­ and right intestinal limb, open ing almost mid­ and postovarian . Vas deferens strongly winding ventrally behind cirrus pouch; seminal recepta ­ in median field between testes and vagina; in cle well developed. Gill parasi tes of marine the region between the vagina and the pars teleosts. muscularis there are nume rous prostate cells, TYPE SP ECIES : L. etelis n. sp., on Etelis car­ though the pars prostatica is not distinctl y dif­ bunculns; H awaii. ferentiated. Pars muscularis representing ejacu­ latory duct, 0.35-0.45 mm long by 40-60[! 4. M etopisthogYl1e sphyraenae n. gen., n , sp. wide, provided with strong transverse or spiral Fig. 4 muscle fibers, followed by muscular cirrus 0.18­ 0.26 mm long which is bulbously swollen near HABI TAT : Gills of Sphyraena belleri (local its distal end and projects into the nonmuscular name "kawalea' ") ; H awaii. gen ital atrium in the type. Genital atrium open­ HOLOTYPE : U. S. N at. Mus. Helm. Coll., ing on left margin of body at a distance of S. Y. N o. 48 . 0.55-0.8 mm from head end . DESCRIPTION (based on five whole mounts) : Ovary tubular, long, folded back on itself Body 4.4--8 .9 mm long, slender, gradually just medial to left intestinal limb, 0.3- 0.4 mm widened toward opisthohaptor which is 0.8-2.0 long lineally as a whole, arising about one-third mm long by 0.6-1.0 mm wide at base and bears of body length from posterior extremity. Ger­ four pairs of short-stalked clamps and a short, miduct giving rise to genito-intestinal duct be­ trapezoidal, median, caudal lappet provided fore joining vitelline reservoir. This duct opens with three pairs of hooks. Clamp skeleton into the left intestinal limb a little anterior to 0.24--0.3 mm in transverse diameter, consisting the distal end of the ovary.Uterus midventral, of a very stout median spr ing, a pair of inner containing only one fusiform egg in the type. basal sclerites, two pairs of arcuate lateral scle­ Eggs 0.17-0.18 mm long, with rigid bipolar rites and a pair of accessory sclerites ; one prong filaments 0.1 5-0.21 mm long. Vitellaria largely 426 PACIFIC SCIENCE, Vol. XX, October 1966

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FIG. 4. Met opishogyne sphyraenae n. g., n. sp. 4A, H olotype, ventral view; 48 and 4C, enlarged anterior and posterior regions of holotype, ventral view; 4D, clamp of paratype ; 4£, anchors on caudal appendage of paratype ; 4F, termin al genitalia of holotype, ventral view; 4G, vagina of paratype, ventral view. N ew Monogenetic Trematodes, II-YAMAGUTI 427

coextensive with intestine, commencing a little length exclusive of haptoral clamps, up to 4.5 behind vagina l pore and terminating at base of mm in length including clamps, 0.12-0.26 mm opisthohap tor ; vitelline reservoir Y-shaped, in wid e in ovariotesticular region. Opisthohaptor ovarian zone. Vagina funnel-shaped, strongly fan-shaped, asymmetrical, on posterior exten­ muscular, sending out a short narrow duct on sion of body proper, with nine pedunculate each side of its anterior end. This duct appears clamps. As numbered from the right end of the to be connected with the anterior end of the opisthohaptor of the type the first to the ninth longitudinal vitelline duct of its own side, al­ clamp gave the following measurements, pre­ though no distinct connecting duct is seen. senting different features respectively: Vaginal pore middorsal, postbifurcal, provided (1 ) First clamp 0.18 rom long, divided into with a conspicuous bulb of fine lamellar muscle a caudal appendage bearing a pair of large sub­ fibers, situated at a distance of 1.2-2.25 mm apical anchors 37-48fllong and two more, very from head end . small, apical hooklets 9- 15fl long, and a shorter DISCUSSION : This genus differs markedly from clamp than others. This clamp consists of two Opisthogyne Unnithan, 1962, in the distribu­ opposing valves fringed on each side with tion of the testes. In Opisthogyne the testes are about a dozen curved spines and supp orted by limited to the preovarian region, whereas in the comparatively short stout sclerites. present genus they are much more numerous (2) Second clamp arising from common and more extensive. The V-shaped ridges charac­ trunk with first, 0.25 mm long, consisting of teristic of Opisth ogyne and Gemmacaputia Tri­ a slender stalk about 0.2 mm long, and pro­ pathi, 1959, are absent in the posterior part of vided on each side with membrano us fr inge the body in the present genus. supported by a row of about a dozen acicular spines and a single axial sclerite ; apical clamp M etopistb ogyne n. gen. valve single, fringed with over a dozen curved spines. GENERIC DIAGN OSIS: Discocotylidae, Opis­ (3 ) Third clamp about 0.4 mm long from thogyninae. Body symmetrical, elongate, with­ its basal two-valved sucker to tip of double out V-shaped ridges posteriorly. Four pairs of terminal clamp valve; its stalk supported by two similar clamps of Gastrocotyle type. Termin al unequal axial sclerites, one of which articulates lappet with three pairs of hooks. Esophagus with the sclerite of the second clamp at the base, long ; intestine with side branches, terminating while the other slender one articulates with the separately. Testes num erous, mainly preova rian, stronger axial sclerite of the fourth clamp ; partly para- and postovarian. Ductus ejaculate ­ axial clamp valves pressed against each other. rius strongly muscular. Cirrus muscular, un­ (4) Fourth clamp 0.38 mm long, similar in armed. Genital pore ventromarginal. Ovary structure to the thi rd, with doub le apical clamp tubular, folded back on itself in posterior half valve, bearing at base a two-valved sucker on of body; eggs fusiform, with filament at each the right and a larval lappet on the left. This pole. Vitellaria coextensive with intestine. Vag­ lappet is a plump rod-shaped lobe 25-40fllong inal pore middorsal, immediately postbifur cal. by 15-22fl wide and bears two pairs of very Gill parasites of marin e teleosts. small larval anchors 12-17fl long. TYPE SP ECIES: M. sphyraenae n. sp., on 5phy­ (5) Fifth clamp 0.47 mm long from its raena belleri; H awaii. basal sucker to apex which consists of two similar valves. 5. Pseudopterinotrema albulae n. g., n. sp. ( 6) Sixth clamp 0.25 mm long, with double Fig. 5 apical valve similar in structure to that of third. HABITAT : Gills of Albula uulpes; H awaii. (7) Seventh clamp 0.23 mm long ; terminal HOLOTYPE : U. S. Nat. M us. H elm. ColI., clamp valves symmetrical. S.Y. N o. 49 . (8) Eighth clamp about 0.18 mm long, with DESCRIPTION ( based on 26 whole mounts) : two separate apical valves and a common stalk Body slender, cylindr ical, 1.75-2.4 mm in supported by two parallel axial sclerites, of 428 PACIFIC SCIENCE, Vol. XX, October 1966

which the right one articulates with the left axial sclerite of the seventh clamp and the left one articulates with the extreme left ninth sclerite. (9) Ninth clamp about 0.12 mm long and fringed on each side with a row of spines like other clamp stalks, but bears one apical clamp valve, although it has a two-valved sucker on the left side of its base. The above mentioned two-valved suckers, 23-40!l wide and seven in all, are arranged in a transverse row at the base of the clamps. Each sucker has a sclerotized frame consisting of four sclerites and appears 00 -shaped in pro­ file. , Prohaptor circular, 0.2-0.47 mm in diameter, s .; membranous, with somewhat crenulated margin and a simple middorsal cone 40-70!l long and 40-70!l wide at base. Oral sucker 0.11-0.21 mm 58 in diameter, opening at bottom of prohaptor ; prepharynx present ; pharynx always lateral to oral sucker, cylindrical, 40- 60 X 20-30!l; esophagus very narrow, 0.3-0.65 mm long. Ceca 0 with short branches, terminating separately at base of opisthohaptor. Testes rounded , up to 25 in number (mostly 16), arranged in a zigzag longitudinal row, occupying greater part of postovarian inter­ intestinal field. Vas deferens may be strongly "y J) swollen in preovarian interintestinal field. Cirrus plug-shaped, muscular, covered inside j 5c with spinules, 50- 90 X 27-50!l, with two un­ ~ equal sclerotized filaments at base; anterior filament 50- 120!l long, usually widened distally, posterior hook-shaped, 35-60!l long, both often appressed against cirrus. Genital pore ventro­ median, 0.06-0.22 mm posterior to pharynx. Ovary turned back on itself five times, form­ ing N-shaped loop posteriorly and double loop anteriorly, situated in anterior part of middle third of body. The germiduct runnin g forward gives off the genito-intestinal duct near its origin and soon unites with the descending vitelline stem. Uterus largely ventromedian ; eggs elliptical, 110-130 X 50-75!l' with long, very fine filament at antiopercular pole. Vitel­ FIG. 5. Pseudopterlnotrema alubulae n. g., n. sp. laria coextensive with intestinal limbs; vitelline 5A, Holotype, ventral view ; 5B, two-valved sucker; reservoir Y-shaped, with long, sometimes short, 5C, anchors on caud al app endage of holotype ; 5D , cirrus and its accessory sc1erites of paratype, dorsal stem, and rather short arms, coinciding with view; 5E, egg . ovary. Vagina well cuticularized, with wide mid- N ew Monogenetic Trematodes, II-Y AMAGUTI 429 dorsal opening 0.1-0.35 mm posterior to gen­ 6. Slbitrema poonui n. g., n. sp. ital pore, usually anterio r to anterior end of Fig. 6 vitellaria, but sometimes much posterior to this H ABITAT : Gills of Parathennus sibi (local level. Vaginal duct inverted Y-shaped, each name "poonui" ); H awaii. branch opening into arm of vitelline reservoir H OLOTYP E: U. S. N at. Mus. Helm. CoIl., of its own side. S. Y. N o. 50. DISCUSSION : This genus bears a superficial DESCRIPTION (based on a single gravid speci­ resemblance to Pterinotrema Caballero, Bravo­ men) : Body 19.2 mm in total length, distinctly Hollis, and Grocott, 1954, but differs from it divided into three regions: body proper, hap­ fundamentally in the structure of the clamps toral stalk, and haptoral region. Body proper and the terminal genitalia, and in possessing slender, lanceolate, tapered anteriorly, with a a typical oral sucker and a pharynx. I prefer to pair of compact eyespots, constricted behind, separate it as representing a new genus, for 11.7 mm long, 1.4 mm wide in posterior part which the name Pseudopterinotrema is sug­ where the ovary is situated; haptoral stalk fusi­ gested, with the following diagnosis. form, 4.3 X 0.45 mm, containing intestine and vitelline gland alone, attenuated posteriorly and Pseudopteriuotr ema n. g. then gradually enlarged to pass into haptoral region which is spatulate, produced posteriorly GENERIC DIAGN OSIS: Pterinotrematidae. Body into a conical terminal appendage. This appen­ small, cylindrical. Prohaptor circular, with a dage is 0.2 mm long, 0.2 mm wide at the base, dorsal conical papilla. Opisthohaptor with nine and bears on the ventral surface of its apex long-stalked clamps, one of which, to the ex­ two pairs of larval hooklets of different size; treme right in the type, bears an armed caudal outer pair 46ft long, inner pair 21ft long, both appendage. Each clamp, except for two extreme with a very prominent guard and a well curved right ones, with two axial sclerites fringed with blade. On the left border of the haptoral region spines on its stalk, and two terminal clamp is a single longitudinal row (a bout 3 mm long) valves which are also fringed with spinelets. A of 48 clamps 50-90ft in transverse diameter. transverse row of six small, two-valved suckers Clamp skeleton consisting of a pair of inner present at base of third to seventh clamp stalks, basal processes, two pairs of lateral arms, a pair extreme left one to left of base of ninth sclerite. of accessory pieces meeting in median line, and At base of fourth clamp is a rod-shaped lobe a stout median sprin g, one end of which is bearing two pairs of very small larval hooklets. anchor -shaped , while the other end is sur­ Oral sucker and pharynx present. Intestinal mounted by a Y-shaped apical piece. Mouth limbs with short outer branches , terminating cavity wide, opening ventroterminally, with oval separately at base of opisthohaptor. A number paired suckers (46 X 23ft) laterally and a of rounded testes in a zigzag longitud inal row globular, weakly muscular, median pharynx at in posterior interintestinal field. Copulatory or­ its bottom ; esophagus simple, 1.45 mm long, gan consisting of plug-shaped, muscular, spined contra cted at beginning, but soon enlarged to cirrus and two accessory sclerites. Genital pore width of 0.15 mm, bifurcating immediately be­ ventromedian, immediately behin d prohaptor. hind genital pore. Intestinal limbs with numer­ Ovary tubular, looped, pretesticular. Vagina ous short inner and longer outer branches; sclerotized, opening middorsally near intestinal right limb terminating at base of terminal bifurcation ; vaginal duct inverted Y-shaped, appendage, left one 0.5 mm farther in fr ont. each branch connected with arm of vitelline Testes rounded, 75 in total number, pre-, reservoir of its own side. Eggs elliptical, fila­ para-, and postovarian ; preovarian testes in two mented at antiopercular pole. Vitellaria coex­ parallel submedian rows of 15 or 16 each; para­ tensive with intestine. Gill parasites of marine ovarian testes 18 or 19, in two longitudinal rows teleosts. immediately outside ovarian loop ; behind the TY PE SPECIES: P. albttlae n. sp., on A lbul« ovary there are only several testes in the median oulpes; H awaii. field. Vas deferens median, dorsal to uterus; 430 PACIFIC SCIENCE, Vol. XX , October 1966

p 6F

GA

FIG. 6. Sibitrema poonui n. g., n. sp. 6A , Hol otype, ventral view; 68 and 6C, enlarged anterior and posterior regions of holotype, ventral view ; 6D, clamp ; 6E, anchors on caudal appendage of holotype; 6F, terminal genitalia of paratype, dorsal view ; 6G, egg. N ew Monogenetic Trematodes, II-YAM AGUTI 431 bulbus cirri weakly muscular, 70f! in diameter, anchors. Clamp skeleton consisting of two pairs situated just ventral to intestinal bifurcation. of lateral sclerites, one pair of basal inner Cirrus consisting of several sharp-pointed spines sclerites, an arcuate median spring, and a pair which are 35f! long and bundled together im­ of accessory sclerites. A terminal lappet bearing mediately in front of atrial crown of 12 spines ; larval hooklets present. Testes numerous, pre-, these spines are 51-56f! in length including base para-, and postovarian. Ovary inverted U­ which forms a ring of 12 backwardly directed shaped. Vaginae double, symmetrical. prongs; the shaft of each spine is straight, but the apex is curved inward and bifid at the tip. Slbltrema n. g. This crown of spines is enclosed in a very thick­ GENERIC DIAGNOSIS: Axinid ae, Sibitremati­ walled atrial bulb of radial muscle fibers, which nae. Body long, divided into three distinct in turn is enclosed in a membranous genital regions: body prop er, haptoral stalk, and opis­ atrium . Genital pore midventral, at anterior thohaptor with a row of numerous clamps uni­ end of genital atrium, 1.45 mm from head end. laterally and a terminal lappet bearing two pairs Ovary tubular, bent back on itself on right of anchors. Paired oral suckers poorly devel­ side of median line, 3.15 rom long as a whole, oped. Esophagus bifurcating near genital pore. swollen ( 0.3 mm wide) at postequatorial proxi­ Intestinal limbs with numerous side branches, mal end in form of a recurved mass and at distal terminating blindly near base of terminal lappet. end in form of a club, from the posterior end of Testes numerous, pre-, para-, and postovarian. which the germiduct arises. Genito-intestinal Genital atrium membranous, immediately pre­ canal arising from near middle of germiduct, bifurcal, enclosing atrial bulb of radial muscle runnin g obliquely forward across proximal por­ fibers at bottom, latter in turn provided inside tion of ovary ventrally to empty into right intes­ with a crown of spines, beyond which the tinal limb. Vitelline follicles small, coextensive bundl ed cirrus spines project forward. Ovary with intestinal branches, commencing a little tubular, bent back on itself in middle third of behind vaginae; vitelline reservoir Y-shaped, to body. Genito-intestinal canal crossing proximal left of distal end of ovary, connected with portion of ovary. Eggs with filament at each germiduct by a narrow descending median stem pole. Vitellaria coextensive with intestinal 0.15 mm long. Uterus sraight , midventral, con­ branches ; vitelline reservoir Y-shaped, in ovar­ taining a few eggs; eggs fusiform, 0.23-0.25 ian region. Vaginae divided into a series of X 0.07-0.09 mm, with filament 40-60f! long several areolae, situated about halfway between at each pole. Vaginae symmetrical, about 0.5 genital pore and anterior end of vitellaria. Gill mm long, divided into a series of several (8­ parasites of marine teleosts. 14 ) areolae, situated laterally about halfway TYPE SPECIES: S. poonni n. sp., on Paratbun­ between genital pore and anterior end of vitel­ Il/IJ sibi; Hawaii. laria. DISCUSSION: This genus closely resembles Allopsendaxine Yamaguti, 1943, in intern al 7. Cypselurobranchitre11la spilonotopteri anatomy, but differs markedly in general body n. g., n. sp. shape and, what is more important, in the Fig. 7 structure of the clamp. On the basis of the latter HA BITAT: Gills of Cypselurus spilon otop­ difference I prefer to propose the new subfamily terns; H awaii. Sibitrematinae for its reception, with the follow­ HOLOTYPE: U. S. Nat. Mus. Helm. ColI., ing diagnosis. S. Y. No. 51. DESCRIPTION (based on four whole mounts) : Body 7- 10 mm in total length , enlarged later­ Sibitrematinae n. subf. ally up to 2.5-3.5 mm wide in midregion: SU BFA MILY DIAGNOSIS : Axinidae. Body anterior third abruptly tapered toward head end divided into three distinct regions. Opisthohap­ which is 0.2-0.4 mm wide at the level of the tor asymmetrical, without prehaptoral larval oral suckers ; posterior third occupied by large 432 PACIFIC SCIENCE, Vol. XX, October 1966

II

7c

I III

FIG. 7. Cypselnrobrancbitrem« spilonotopteri n. g., n. sp. 7A , Holotype, ventral view ; 7B, clamp ; 7C, an­ chors on caud al appendage of holotype (1) and two par atypes (II and III) ; 7D, anterior extr emity of para­ type, ventral view ; 7E, terminal gen itali a of para type, ventral view; 7F, mature eggs from paratype. N ew Monogenetic Trematodes, II-YAMAGUTI 433 cotylophore which is 2.4-4.2 mm long by 2.8­ cells; posterior outer branches extending into 3.8 mm wide and extends on the ventral side basal portion of clamp stalks. from behind the posterior end of the ovary to Testes rounded, about so in total numb er, a considerable distance back of the posterior arranged in two zigzag longitudinal rows, one end of the body proper. In the type this cotylo­ on each side of median line; anterior ones pre­ phore begins in the midventral region at the ovarian, posterior ones para-ovarian, some be­ level of the junction of the middl e with the tween ovarian limbs. Vas defer ens straight or posterior third of the entir e body with a smooth gently undul ating in median field, surrounded semicircular fold 1.2 mm wide which is fol­ at its distal end by prostate cells; no pars pro­ lowed by a twisted, fan-shaped body fold statica differentiated. A distinct globular bulb fringed with a semicircular row of 18 or 19 of very fine muscle fibers is developed around long-stalked clamps. For convenience of refer­ the somewhat swollen distal end of the ejacula. ence the clamps are numbe red from in front tory duct. Cirrus represented by a cylindrical backwards; the first clamp next to the semi­ group of very fine acicular spines, enclosed circular fold is the smallest (about 0.2 mm in basally in a crown of 18 hooks, which in turn diameter) , rather short-stalked, the 12th may is enclosed in the atrial bulb with thick walls be slightly out of the row of other clamps, the of radial muscle fibers. The hooks are fused 14th to 16th are the largest (up to 0.45 mm in near the base, and their simple attenuated diameter), with longer stalks, and the last 18th points are curved inwards. This thick-walled (19th in one paratype) attached to the right atrial bulb is 5I- 80ft in outside diameter, and posterior end of the body proper is provided on enclosed entirely in the genital atrium with a the proximal anterior margin of its stalk with membranous wall. Genital pore midventral, a blunt-conical or subcylindrica l caudal appen ­ immediately in front of the above mentioned dage 0.15-0.16 mm long. This caudal appen­ thick-walled atrial bulb, 0.5-0.7 mm from head dage is armed in the type with a small guarded end. apical hook 35ft long and two dissimilar sub­ Ovary inverted U-shaped, 2.35 mm long by apical hooks, one of which is 77ft long and 0.4 mm wide as a whole in the type, enlarged guarded like the apical hook, but the other is at proxi mal end to an elongate compact mass, simple, falcate and 37ft long lineally. In the situated to right of median line in middle th ird paratypes either the guarded subapical or the of body. Genito-intestinal duct arising from falcate hook is absent (see Fig. 7C), so that the germ iduct just before the latter unites with the armature of this appendage is variable. Clamp stem of the vitelline reservoir. Ootype postero­ skeleton 0.18-0.46 mm in diameter, consisting sinistral to this genital junction. Uterus proper of an arcuate, perfo rated, median spring, and alongside vas deferens, opening into genital two pairs of curved lateral arms articulating atrium ventral to male duct. Mature eggs elon­ with each other, of which the smaller pair gate oval, 0.25- 0:26 X 0.11-0.15 mm, with a articulates at the distal end with a small A­ rigid filament at each pole; anterior filament shaped accessory sclerite. 0.19-0.26 mm long, posterior filament 0.12­ H ead end rounded; mouth aperture wide, 0.2 mm long, slightly enlarged at tip. Genito­ subterminal; oral suckers paired, muscular, sep­ intestinal duct running straight obliquely for­ tate, 53-81 X 65-93ft; pharynx oval, weakly ward and emptying into right intestinal limb, muscular, 116 X 98ft in the type. Esophagus with distinct accompanying cells. Vaginae in­ simple, 0.5-0.7 mm long, bifurcating a little distinct in the type, but present on each side in behind genital pore. It is not certain whether form of a ventrosubmarginal longitudinal row the intestinal limbs are confluent posteriorly or of several rud imentary areolae just behind level not ; there are wide anterolaterally directed of symmetrical excretory pores in one of the diverticles on each side anteriorly ( Fig. 7D) , paratypes. Vitelline reservoir Y-shaped, with the remaining greater part with few short inner, short arms. Excretory pores symmetrical, dorsal, and numerous longer, subdivided, outer submarginal at about level of genital pore or a branches accompanied by vitellaria and pigment little posterior to it. 434 PACIFIC SCIENCE, Vol. XX, October 1966

DISCUSSION: This genus is very closely re­ ovarian. Prostate cells around distal end of vas lated to Allopseudaxinoides Yamaguti, 1965,2 deferens; ejaculatory duct enclosed in muscle in general internal anatomy, but differs from bulb. Cirrus represented by a cylinder of very it in the arrangement of clamps and in posses­ fine acicular spines, surrounded basally by a sing septate oral suckers but no reticular anas­ ring of hooks, which in turn is enclosed in tomosis of the anteriormost vitelline ducts. atrial bulb with thick walls of radial muscle On the basis of these differences I prefer to fibers. Genital atrium opening ventral to esoph­ create the new genus Cypselurobrancbitrema, agus. Ovary inverted U-shaped, submedian, for which a new subfamily Cypselurobranchi­ in midregion of body. Genito-intestinal duct trematinae is suggested, because this genus can­ opening into right intestin al limb. Eggs with not be assigned to Allopseudaxininae Yamaguti, rigid filament at each pole. Vitelline follicles 1963. small, largely coextensive with intestine and its branches, with which they extend into the Cypselurobranchitrematinae n. subfam. stalk of clamps. Vaginae indistinct or opening symmetrically on ventral submarginal surface SUBFAMILY DIAGNOSIS: Axinid ae. Body elon­ a little behind level of genital pore. Parasitic on gate, moderately wide. Op isthohaptor twisted gills of marine teleosts. fan-shaped, attached on ventral side of body TYPE SPECIES : C. spilonotopteri n. sp., on proper at its posterior end, frin ged with a Cypselem s spilonotopterus; Hawaii. numb er of stalked clamps in semicircular row. Oral suckers paired, septate, within oral cavity. REFERENCES Intestine strongly ramified. Testes numerous, pre- and paraovari an. Genital atrium enclosing CABALL ERO Y C. E., M. BRAVO HOLLIS, and armature of complex structure, opening mid­ R. G. GRO COTT. 1954. Helmintos de la ventrally. Ovary tubul ar, in midregion of body. Republica de Panama. XII. Descripcion de Genito-intestinal duct present. Eggs filamented. dos nuevos trematodes monogeneos, parasites Paired vaginae rud imentary or absent. Vitellaria de peces marinos comestibles del Oceano coextensive with intestine and its branches. Gill Pacifico del Norte. Ciencia, Mexico 14(4-6) : parasites of marine fishes. 81-86. JOHNSTON, T. H. 1931. N ew trematodes from Cypselurobranchitrema n. g. the subantarctic and antarctic. Australian J. Exp. BioI. Med. Sci. 8: 91- 98. GENERIC DIAGNOSIS : Axinidae, Cypseluro­ TRIPATHI, Y. R. 1959. Monogenetic trematodes branchitrematinae. Body moderately large, from fishes of Indi a. Indian J. Helminthol. abruptly tapered anteriorly. Op isthohaptor 9(1-2) :1-149. asymmetrical, arising from posterior midventral UNNITHAN, R. V. 1962. On the functional region of body proper, with a twisted semi­ morphology of a new fauna of Monogenoidea circular body fold, which is followed by a on fishes from Trivandrum and environ s. fan-shaped fold fringed with a semicircular Part II. Opisthogynidae fam. nov. (Gastro­ row of a number of stalked clamps; clamp cotyloidea) and Abortipedinae subf. nov. skeleton similar to that of Allopseudaxin oides (Protomicrocotyloidea) . Parasitology 52: Yamaguti , 1965. Caudal appendage with an­ 315-351. chors of different shape and size on stalk of YAMAGUTI, S. 1943. Verzeichnis der ektopara­ last clamp. Intestinal limbs with short inner sitischen Trematoden der japanischen Fische. and longer outer branches. Testes small, ar­ Published by author. 3 pp. ranged in two longitudinal rows, pre- and para- - -- 1963. Systema Helminthum, Vol. IV. Monogenea and Aspidocotylea. Interscien ce 2 Th e origi nal diagnosis of this genus is emended Publishers, New York. 699 pp. as follows: "Vaginae rud imentary, opening dorso­ --- 1965. New monogenetic trematodes submarginally at about level of genit al pore or absent. Anteriormost vitell ine ducts of two sides with reticu­ from Hawaiian fishes, I. Pacific Sci. 19(1): lar anastomosis." 55-95.