New Monogenetic Trematodes from Hawaiian Fishes, IP SATYU YAMAGUTI IN THIS SECOND REPORT are described seven III. Pterinotrematidae Bychowsky and Nagi­ new species 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 fish, 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 Monogenea 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. Capsalidae 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 2A o T j(~f. Ie 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.