A survey of the parasites of Greenland halibut (Reinhardtius hippoglossoides) caught off Atlantic Canada, with notes on their zoogeography in this fish

Abstract

A survey of the parasites of Greenland halibut (Reinhardtius hippoglossoides) caught in Canadian Atlantic waters extending from Cumberland Sound, Northwest Territories, to the Gulf of St. Lawrence and Saguenay Fjord was conducted during the period January 1990 to March 1991. From examination of 350 fish a total of 46 parasite taxa were identified (4 Myxosporea, 1 Monogenea, 19 Digenea, 6 Cestoda, 8 Nematoda, 5 Acanthocephala, 2 Crustacea, and 1 Hirudinoidea). Included among these are 15 taxa previously unreported from this fish (Genolinea laticauda Manter, 1925; Gonocerca phycidis Manter, 1925; Neophasis sp.; Podocotyle reflexa (Creplin, 1825); Prosorhynchus squamatus Odhner, 1905; Steringophorus sp.; Eubothrium parvum Nybelin, 1922; Proteocephalus sp.; Ascarophis arctica Polyansky, 1952; Ascarophis filiformis Polyansky, 1952; Spirurida gen. sp. larva; Corynosoma validum Van Cleave, 1953; Corynosoma wegeneri Heinze, 1934; Gnathia elongata (Krøyer, 1849); and Notostomum laeve Levinsen, 1882). New Canadian records include only Steringophorus sp. and N. laeve. The parasite fauna of Greenland halibut is characterized by a large number of ubiquitous species, including many larval forms that show little host specificity, and a smaller number of species typical of pleuronectiform fishes, two of which (Myxoproteus reinhardti (Wierzbicka, 1986) and Hatschekia reinhardtii Wierzbicka, 1989) are known only from this fish. A complete listing of all parasites reported from Greenland halibut is included as an appendix.