Myxosporida in macrourid fishes of the North Atlantic

Abstract

Myxosporidan parasites inhabiting some macrourid fishes from the North Atlantic are surveyed. Myxosporida recovered were Myxidium coryphaenoidium Noble, 1966, in the gall bladders of Macrourus rupestris from Norway and Nezumia bairdi from Greenland; Davisia newfoundlandia n. sp. and Zschokkella parasiluri Fujita, 1927, in the kidney of Macrourus berglax from Newfoundland; Auerbachia sp. in the gall bladder of M. berglax from Newfoundland and Iceland; and Leptotheca coelorhyncha n. sp. in the gall bladder of Coelorhynchus coelorhynchus from Ireland.Myxidium coryphaenoidium appears to be the most widely distributed myxosporidan species in macrourids, occurring in both the Atlantic and Pacific. They are known to inhabit waters from 400 to 3960 m in depth. Of the macrourids studied to date, 14 of 19 (73.7%) Macrourus berglax harbored three species of Myxosporida; 27 of 48 (56.3%) M. rupestris, two of four (50.0%) Nezumia bairdi, and two of seven (28.6%) Coelorhynchus coelorhynchus, each harbored one species of Myxosporida. Relatively high incidences of infections are suggestive of dense host populations, but little is known about population densities in deep benthic waters. A brief discussion of the geographic distribution of M. berglax and M. rupestris is included. Previously reported myxosporidan parasites from macrourids are mentioned.