New and Previously Known Dactylogyrus spp. from Southern Ontario Fishes

Abstract

Six new and 15 previously described species of Dactylogyrus are reported: Dactylogyrus cernyi sp. n. and D. micropogoni sp. n. from Nocomis micropogon (Cope); D. chrosomi sp. n. and D. eos sp. n. from Phoxinus eos (Cope); D. hankinsoni sp. n. from Hybognathus hankinsoni Hubbs; D. heterolepis sp. n. from Notropis heterolepis Eigenmann and Eigenmann; and D. apos Mueller, 1938; D. atratuli Hanek and Fernando, 1972; D. attenuatus Mizelle and Klucka, 1953; D. banghami Mizelle and Donahue, 1944; D. bifurcatus Mizelle, 1937; D. bulbus Mueller, 1938; D. bychowskyi Mizelle, 1937; D. cornutus Mueller, 1938; D. dubius Mizelle and Klucka, 1953; D. eucalius Mizelle and Regensberger, 1945; D. lachneri Chien, 1971; D. luxili Rogers, 1967; D. microphallus Mueller, 1938; D. reciprocus Rogers, 1967; and D. rubellus Mueller, 1938. D. dubius is redescribed, and the vagina of D. luxili is figured. Studies on Dactylogyrus Diesing, 1850, in Canada have been made by Bangham (1955), Bangham and Adams (1954), Dechtiar (1972), Hanek and Fernando (1972), Mizelle and Donahue (1944), Monaco and Mizelle (1955), and Price and Arai (1967). From April to October 1973 we undertook intensive parasitological investigation of fishes from southern Ontario. Six new and 15 previously described species of Dactylogyrus were collected and are reported herein. MATERIALS AND METHODS Fish hosts were collected by seine and immediately segregated by species, transported to the laboratory alive, and examined. The hosts were identified using the keys of Hubbs and Lagler (1964), while systematic assignment of the species follows that proposed by the American Fisheries Society (1970). All dactylogyrids were collected from the gills and fixed in a mixture of glycerol and formalin (9:1) with a few drops of ammonium picrate. Measurements are in micrometers; those of holotypes are given first with ranges in parentheses. Observations were made with a phasecontrast microscope and illustrations were prepared with the aid of a camera lucida. RESULTS AND DISCUSSION Dactylogyrus cernyi sp. n. (Figs. 1a-b, d-f) Type host and locality: Nocomis micropogon (Cope); Conestogo River, Waterloo. Specimens studied: 2. Received for publication 14 January 1974. *Present address: Ministry of Agriculture and Fisheries, Nassau, N.P., Bahamas. t On leave from Veterinary Medical Research Institute, Academy of Sciences, Budapest, Hungary. 421 Type specimens: Holotype, USNM Helm. Coll. No. 73150; paratype No. 73151.