Digenetic Trematodes from Marine Fishes of Waltair Coast, Bay of Bengal. I. Family Lepocreadiidae

Abstract

Twelve species of lepocreadiid trematodes are reported from marine fishes of Waltair Coast. These include 3 new genera: Lobalocreadium, Opisthogonoporoides, and Cotylocreadium, and 6 new species: Preptetos chaetodoni sp. n. from Chaetodon pictus; Opechona waltairensis sp. n. from Rastrelliger kanagurta; Lobatocreadium manteri gen. et sp. n. from Sufflamen capistratus and Hemibalistes chrysoptera; Multitestis bengalensis sp. n. from Platax teira; Opisthogonoporoides hanumanthai gen. et sp. n. from Siganus oramin, Acanthurus mata, and A. strigosus; and Pseudocreadium indicum sp. n. from Monacanthus choirocephalus. Other species reported are Opechona bacillaris (Molin, 1859), Lepocreadioides indicum Srivastava, 1941, Transversocreadium cablei Hafeezullah, 1970, Bianium plicitum (Linton, 1928), Cotylocreadium triacanthi (Hafeezullah, 1970) gen. et comb. n., and Aephnidiogenes senegalensis Dollfus and Capron, 1958. The new combinations suggested are: Lobatocreadium exiguum (Manter, 1963) for Lepocreadium exiguum Manter, 1963; and Cotylocreadium triacanthi (Hafeezullah, 1970) for Diplocreadium triacanthi Hafeezullah, 1970. This paper is the first in the series of the papers to be published by the author on the digenetic trematodes collected from marine fishes of Waltair Coast, Bay of Bengal, India. The trematodes were collected over a period of 3 years. Twelve lepocreadiid trematodes, six of which are new, are reported. Parasites were washed in saline, fixed in AFA under cover glass pressure, stained in alum carmine or Delafield's hematoxylin, and mounted in balsam. All measurements are given in microns. Sucker ratios were computed from the average of length and width. Type specimens are deposited in the U. S. National Museum Helminthological Collections. Preptetos chaetodoni sp. n. (Figs. 1, 2) Host: Chaetodon pictus (Forskal), butterfly fish (Chaetodontidae). Location: Intestine. Number: 94 from 6 of 8 hosts. Holotype: USNM Helm. Coll. No. 72227. Description (measurements on 8 specimens): Body fusiform, pointed at each end, 1,488 to 2,640 long and 832 to 1,552 in maximum width; forebody 400 to 624 long without evident eyespot pigment; cuticle spined to level of ovary, spines often lost. Oral sucker 78 to 117 long by 86 to 137 wide; acetabulum in anterior third of body, 94 to 203 long by 98 to 168 wide, sucker ratio 1:1.2 to 2.0. Prepharynx absent; pharynx 59 to 86 long by 86 to 137 wide; esophagus 50 to 137 long; cecal bifurcation about midway between suckers, ceca narrow anteriorly, broader posteriorly terminating blindly at posterior end. Received for publication 13 July 1971. Genital pore to left of cecum at level of intestinal bifurcation. Testes large, smooth or crenulated, longer than wide, equal or subequal, 272 to 480 long by 224 to 400 wide, separated by excretory bladder, situated in middle of hindbody; posttesticular space 384 to 768. Cirrus sac stout, 242 to 390 long by 86 to 156 wide, preacetabular or just reaching acetabulum, extending obliquely, containing small seminal vesicle, oval prostatic vesicle, and muscular protrusible cirrus; genital atrium large; external seminal vesicle large, sinuous, tubular, extending posterior to acetabulum to about midway between acetabulum and ovary. Ovary median, deeply lobed, to left of anterior testis or slightly more anterior; large seminal receptacle between ovary and posterior testis; Mehlis' gland preovarian; Laurer's canal present. Vitelline follicles moderately large extending from level of intestinal bifurcation to posterior end of body, circumcecal, filling most of posttesticular space except region occupied by excretory bladder. Uterus preovarian, confined to left side, not extending beyond ceca, modified terminally into a short, thick metraterm opening into genital atrium. Eggs large, oval, 59 to 66 long by 35 to 43 wide. Excretory bladder I-shaped, long, extending between testes to anterior margin of acetabulum and then curving round anterior margin of acetabulum.