Some Digenetic Trematodes from Fishes of the Bering Sea with the Descriptions of Prosorhynchus Mizellei Sp. N. (Bucephalidae) and Pseudopecoelus Nossamani Sp

OF WASHINGTON, VOLUME 44, NUMBER 1, JANUARY 1977 73

Some Digenetic Trematodes from Fishes of the Bering Sea with the Descriptions of Prosorhynchus mizellei sp. n. (Bucephalidae) and Pseudopecoelus nossamani sp. n. (Opecoelidae)

GUNTHER O. W. KRUSE School of Life Sciences, University of Nebraska-Lincoln and Harold W. Manter Laboratory, Division of Parasitology, University of Nebraska State Museum, Lincoln, Nebraska 68588

ABSTRACT: Prosorhynchus mizellei sp. n. (Buceplialidae), described from Aptocyclus ventricosus (Pallas), differs from P. squamatus Odhner, 1905, in the size of the pharynx and distribution of the vitellaria. Pseudopecoelus nossamani sp. n. (Opecoelidae), described from Ilippoglossus stenolepis Schmidt, is most similar to P. japonicus (Yamaguti, 1938) Von Wicklen, 1946, and P. vulgaris (Manter, 1934) Von Wicklen, 1946, from which it differs conspicuously in the sucker ratio. Derogenes varicus (O. F. Miiller, 1784) Looss, 1901 (Hemiuridae), is reported from three new hosts: Ronquilus jordani (Gilbert), Lycodes palearis Gilbert, Hemtiepidotus hemilepidotus (Tilesius).

This report is based on digeneans collected short, indistinct, apparently contracted; intes- in 1973 by Dr. John D. Mizelle from fishes tine saccular, extending anterodorsally. Testes taken near Amchitka. They were found during dextral, rounded, 152-184 (167) in diameter, routine examination for monogeneans using oblique or tandem, close or overlapping; post- methods described by Mizelle (1938). testicular space 441-586 (511), about Vi body The trematodes were fixed and stored in length. Cirrus sac sinistral, 400-578 (528) 70% ethanol; whole mounts were stained with long by 168-240 (200) wide, extending to near Mayer's hematoxylin; two specimens of the pharynx; seminal vesicle occupying anterior bucephalid were sectioned at 6 microns and half or two-thirds of cirrus sac, sometimes stained with hematoxylin and eosin; all material recurved distally, 280-460 (364) long by 104- was dehydrated, cleared in xylene, and mounted 128 (116) wide; sperm-free duct joining well- in Canada balsam. Drawings were made with developed prostatic complex; genital lobe the aid of a camera lucida; measurements are curved; genital atrium spacious; genital pore in microns with averages in parentheses. sub t e r m i n a l . Ovary 192-224 (211) in diameter, larger than testes and anterior or antero- Bucephalidae lateral to testes, lateral or posterolateral to Prosorhynchus mizellei sp. n. pharynx. Vitelline follicles rounded, 25-29 in (Figs. 1 and 2) number, forming arc from level of pharynx HOST: Aptocyclus ventricosus (Pallas), Cy- halfway to base of rhynchus. Uterine coils few, clopteridae; Smooth lumpsucker; 9 specimens usually postpharyngeal (extending slightly anterior to pharynx in 2 specimens), joining from 1 host. TYPE SPECIMENS DEPOSITED: USNM Hel- genital atrium laterally. Eggs 32-40 (37) long minth. Coll. No. 74119 (holotype), 74120, by 20 wide. Excretory vesicle extending to Univ. Nebraska State Mus., H. W. Manter Lab. posterior testis, dextral to cirrus sac; excretory No. 20314. pore terminal. DESCRIPTION (based on 9 specimens): Body DISCUSSION: This species of Prosorhynchus' subpyriform, 1665-2438 (1879) long by 449- is named in honor of Dr. Mizelle. It is most 685 (598) wide, tapered anteriorly, rounded similar to P. squamatus Odhner, 1905, which posteriorly; tegument spined. Rhynchus coni- has also been reported from Arctic localities. cal, 171-196 (180) long by 96-146 (120) Both species have the vitellaria forming an arc wide. Mouth near midbody; pharynx large, in the anterior half of the body, the gonads round, 130-196 (164) in diameter; esophagus contiguous on the right side, a relatively large

Figures 1 and 2. Prosorhynchus mizellei sp. 11. 1. Holotype, ventral view. 2. Terminal geiiitalia, paratype, dorsal view. Figures 3 and 4. Pseudopecoelus nossamani sp. 11. 3. Holotype, ventral view. 4. Terminal genitalia, paratype, ventral view.

Abbreviations: Ep, excretory pore; Ga, genital atrium; Gl, genital lobe; Gp, genital pore; Mt, metraterm; Pg, prostatic gland cells; Pv, prostatic vesicle; Sv, seminal vesicle; Ut, uterus; Vd, vas deferens.

cirrus sac, and the mouth anterior to the cirrus Opecoelidae sac; but P. mizellei differs from P. squamatus Pseudopecoelus nossamani sp. n. in having a more elongated body, a conspicuously larger pharynx, larger eggs, and the vitel- (Figs. 3 and 4) laria extending posteriorly to the pharyngeal HOST: Hippoglossus stenolepis Schmidt, level (i.e., almost to the anterior of cirrus sac). Pleuronectidae, Pacific halibut; 2 specimens A second species of Prosorhynchus was rep- from 1 host. resented by a single specimen from Hemilepi- TYPE SPECIMENS DEPOSITED: USNM Hel- dotus hemilepidotus (Tilesius), Cottidae; it minth. Coll. No. 74121 (holotype), 74122. could not be identified. DESCRIPTION: Body elongate, 2531-3191

long by 465-539 wide at ovarian level. Tegu- eelpout; 4 specimens from 1 host.—New ment unspined. Forebody conical, a/4 body host record. length. Oral sucker subterminal, 140-160 long Hvmilepidotus hemilepidotus (Tilesius), Cot- by 92-160 wide. Acetabulum slightly protru- tidae, Red Irish lord; 35 specimens from sible, nonpapillate, 204-224 long by 244-276 8 hosts.—New host record. wide. Sucker ratio 1:1.72. Prepharynx short; Hippoglossus stenolepis Schmidt, Pleuronec- pharynx 92-120 long by 76-96 wide; esoph- tidae, Pacific halibut; 18 specimens from agus 156-228 long; intestinal bifurcation 4 hosts. midway between suckers; ceca ending blindly Lepidopsetta bilineata (Ayres), Pleuronec- near posterior end of body. Genital pore ven- tidae, Rock sole; 1 specimen from 1 host. tral, slightly to left of cccal bifurcation. Testes SPECIMENS DEPOSITED: Univ. Nebraska State tandem, intercecal, 236-332 long by 176-232 Mus., H. W. Manter Lab. No. 20316 through wide; posttesticular space 375-510. Seminal 20319. vesicle narrow, sinuous extending from near DISCUSSION: Derogenes various has been genital pore posteriorly to region near ovary; reported with a sucker ratio of 1:1.8 to 2.4. cirrus short; cirrus sac absent; prostatic gland The present specimens have a smaller sucker cells in region of genital pore. Ovary trilobed, ratio, 1:1.42 to 1.84 (1:1.62), as a result of pretesticular, median, 80-112 by .172-180 having a relatively smaller acetabulum, 237— wide; seminal receptacle lacking; Mehlis' gland 392 (313). Derogenes various has been re- preovarian; vitelline follicles circumcecal ex- ported from over 120 hosts and three fish in tending from level of acetabulum to posterior this report are new host records. end of body, interrupted lateral to testes, filling Most reports of this parasite are from the posttesticular space. Uterus preovarian, ex- northern hemisphere, but Derogenes various is tending to acetabulum; metraterm weakly mus- also found in the southern hemisphere. Prud- cular; uncollapsed uterine eggs 80 to 84 long hoe and Bray (1973) reported it from several by 44 wide. Excretory vesicle tubular, ex- sub-Antarctic localities which is in agreement tending to ovary. with Manter's (1954) suggestion that D. various DISCUSSION: The eggs in these specimens has a bipolar distribution. It is very common are larger than those of all other known species in colder regions but limited to fishes in deeper of Pseudopecoelus except for P. japonicus (Ya- (colder) waters in the subtropical and tropical maguti, 1938) Von Wicklen, 1946 (63-84 long regions. by 36-54 wide) and P. vulgaris (Manter, 1934) Szidat (1950) described D. parvus from Von Wicklen, 1946 (young worms: 78-80 long Eleginops maclovinus (Cuvier and Valencien- by 40 wide; older worms: 90-127 long by nes) of Tierra del Fuego and reported it again 50-76 wide). The sucker ratio of Pseudo- in 1965 in Notothenia neglecta Nybelin (1 pecoelus japonicus is smaller (1:1.2—1.3) and specimen—Szidat says that it was probably an that of P. vulgaris is larger (1:2-3). The spe- accidental infection) from the Melchior Archi- cies is named in honor of Bob J. Nossaman, pelago (Antarctic Peninsula) and in Urophycis York College, professor of biology. brasiliemis from Puerto Quequen (Argentina). A second species of Pseudopecoelus was rep- He admitted that it was difficult to distinguish resented by a single specimen from Myxoceph- the two species, but indicated that D. parvus alus polyacanthocephalus (Pallas), Cottidae, differed from D. various only in the super- but it was macerated and cannot be described. ficially lobed vitellaria. The measurements of Hemiuridae D. various given in this report fall into the range for D. parvus. The similarity of the two Derogenes various (O. F. Miiller, 1784) species and the increasing reports of D. various Looss, 1901 from the southern hemisphere suggest a syn- HOSTS: Ronquilus jordani (Gilbert), Bathy- onymy of the two species. masteridae, Northern ronquil; 4 specimens The life-history of Derogenes various is not from 1 host.—New host record. fully known, but Manter (1954) suggested that Lycodes palearis Gilbert, Zoarcidae, Wattled the geographical distribution is probably due

Copyright © 2011, The Helminthological Society of Washington 76 PROCEEDINGS OF THE HELMINTHOLOGICAL SOCIETY to the temperature limitations of the inter- Literature Cited mediate host(s) which are found only in colder Manter, H. W. 1954. Some digenetic trematodes waters. from fishes of New Zealand. Trans. Roy. Soc. Only a few individuals of D. various are N.Z. 82: 475-568. usually found in each host (Manter, 1954; Mizelle, J. D. 1938. Comparative studies on Shorter, 1973). One host in this report (Hemi- trematodes (Gyrodactyloidea) from the gills lepidotus hemilepidotus) harbored 13 mature of North American fresh-water fishes. 111. specimens of this parasite. Biol. Monogr. 17: 1-81. Prudhoe, S. and R. A. Bray. 1973. Digenetic Acknowledgment trematodes from fishes. B.A.N.Z. Antarctic Res. Exped. 1929-1931. Rep.-Ser. B 8: 199- The author wishes to express his appreciation 225. to Drs. John D. Mizelle who collected the speci- Shelter, R. A. 1973. Changes in the parasitic mens, Mary Hanson Pritchard, Curator of the fauna of whiting Odontogadus meiiangus L. Harold W. Manter Laboratory, under whose with age and sex of host, season, and from direction this research was undertaken, and Y. different areas in the vicinity of the Isle of Man. J. Fish. Biol. 5: 559-573. L. Mamaev for sending comparative material Szidat, L. 1950. Los parasites del robalo (Elegi- and depositing it in the Harold W. Manter nops maclovinus Cuv. & Val.). Trab. 1. Cong. Laboratory. Nac. Presquerias Maritimas 2: 235—270.

Histochemical Studies of Abomasal Tissue from Calves with Moiiospecific and Dual Species Infections of Ostertagia ostertagi and Trichostrongylus axei

FRANK STRINGFELLOW Animal Parasitology Institute, Agricultural Research Service, Beltsville, Maryland 20705

ABSTRACT: Abomasal mucosa from three groups of calves each infected with 250,000 larvae of Ostertagia ostertagi, 250,000 Trichostrongijlus axei, or 125,000 each of O. ostertagi and T. axei was studied with histochemical techniques at 3, 5, 7, 14, and 22 days after infection (DAI). O. ostertagi: The capillary network, stained with methods for alkaline phosphatase, was disrupted about the infected gastric gland compared with uninfected mucosa. Methods for carbonic anhydrasc detected less stainable activity in areas about the infected gastric gland than in uninfected and adjacent mucosa because parietal cells were replaced by collagen fibers. T. axei: Cytoplasmic RNA of chief cells stained similarly; whereas, large areas lacked chief cell zymogen granules in infected compared with uninfected mucosa. The capillary network of infected mucosa was compressed because of mucoicl hyperplasia; the stainable carbonic anhydrase activity of parietal cells was similar in infected and uninfected mucosa. O. ostertagi plus T. axei: Cytoplasmic RNA and zymogen granules in chief cells stained similar to calves infected with O. ostertagi. The capillary network was compressed and disrupted about the gastric gland infected with O. ostertagi; and, where hyperplastic mucus cells were abundant, the capillary network was compressed. The stainable carbonic anhydrase activity of parietal cells about the gastric gland was variable depending upon the extent ot mucoicl hyperplasia.

The histopathology of monospecific infec- (1966), Ross et al. (1967, 1968) and Ross et tions of calves infected with Ostertagia oster- al. (1968); however, no extensive histochem- tagi and Trichostrongylus axei and dual species ical studies have been carried out other than infections were described by Ritchie et al. those by Stringfellow (1974) with O. ostertagi.