Helminth Parasites of Embiotocid Fishes. I. A New Genus of the Trematode Family Zoogonidae

Abstract

The parasitic fauna of the viviparous perches of the family Embiotocidae is not well known. The parasites reported in the available literature from hosts of this family are Genitocotyle acirrata Park, Telolecithus pugetensis Lloyd and Guberlet, and Postmonorchis donacis Young. The first named was described by Park (1937) from Holconotus rhodoterus Agassiz taken at Dillon Beach, California and also by Manter and Van Cleave (1951) from Damalichthys vacca Girard taken at La Jolla, California. Lloyd and Guberlet (1932) described T. pugetensis from Cymatogaster aggregata Gibbons taken in Puget Sound, Washington. P. donacis was described by Young (1953) from Micrometrus (undoubtedly M. minimus (Gibbons)), C!ymatogaster (undoubtedly C. aggregata Gibbons), and from Embiotoca jacksoni Agassiz; all taken from Mission Bay, Calif. From one of the species of this family occurring in Japan, Ditrema temmincki Bleeker, Yamaguti (1934; 1939; 1942) has described Decemtestis ditremiatis Yamaguti, Stephanostomum ditrematis (Yamaguti, 1939) Manter, 1947, and Opegaster ditrematis Yamaguti. From the same host, Ozaki (1929) described Coitocaecum latum Ozaki. Haderlie (1953) mentions the absence of helminth parasites in a single specimen of Hysterocarpus traski Gibbons (the only fresh-water embiotocid). This dearth of information is certainly not due to the rarity of the embiotocids. At least nineteen species of this family are well known components of the fish fauna of the California coast (Tarp, 1952). A preliminary survey indicated that these fishes harbor a number of helminth parasites. A detailed parasitological study of these forms has been undertaken in hope of obtaining information which may aid in further understanding the taxonomy and ecology of the embiotocids by determination of apparent host specificity, as well as contributing to our knowledge of the helminth fauna of the Pacific. During the examination of specimens of Embiotoca jacksoni Agassiz taken at Newport Bay and Morro Bay, California, 18 of 26 fishes examined harbored a trematode species belonging to the family Zoogonidae Odhner, 1911. A detailed study revealed that this form cannot be referred to any genus of that family, and it is concluded that the erection of a new genus is required. Appreciation is expressed to Dr. Clark P. Read and to Dr. Boyd W. Walker with whose guidance and assistance this work was carried out.