Ellobiopsidae of Alaskan Coastal Waters

Abstract

Four species of ellobiopsids were taken in Alaskan coastal waters. Thalassomyces fagei (a synonym of Amallocystis fagei) was found to parasitize specimens of the euphausid Thysanoessa raschii taken in Kachemak Bay, Alaska. The development of T. fagei external to the host from a small knob to the mature form was found to occur by repeated dichotomous branching. T. fagei occurred during April and May hut was not observed at other times of the year. Thalassomyces sp. was found to be parasitic on specimens of the mysid Acanthomysis pseudomacropsis taken in Kachemak Bay, Alaska. The range of Thalassomyces capillosus, parasitic on the caridean Pasiphaea pacifica, is extended from Coos Bay, Oregon, to Orca Bay, Prince William Sound, Alaska. Ellobiopsis chattoni was found to parasitize the copepod Metridia longa, a new host of this ellobiopsid. Specimens of E. chattoni were taken in the waters of southeastern Alaska, extending the range of E. chattoni from the Atlantic to the north Pacific.