A new species of Aspidophryxus (Isopoda, Dajidae), ectoparasitic on Mysidella hoshinoi (Mysidae) in Japan.

Michitaka Shimomura

doi:10.3897/zookeys.646.10701

Abstract

A new dajid, Aspidophryxus izuensis sp. n., is described from seven females and six males found infesting the dorsal carapaces of specimens of Mysidella hoshinoi Shimomura, 2016 (Mysidae: Mysidellinae) associated with an unidentified species of sea anemone (Haloclavidae) from Izu-Oshima Island, Sagami Sea, central Japan. Aspidophryxus izuensis sp. n. differs from its congeners in having a body length about as long as wide, widest at the anterior part in females; an elongate frontal part of the cephalon, half as long as wide in females; the frontal margin of the cephalon exceeding the anterior margins of lateral lamellae in females; an unsegmented, vermiform, elongate pleon in females; and a uropod composed of a protopod and an inner and outer ramus in males. A key to worldwide species in the genus is provided.

Highlights

Dajidae, a family of the suborder Cymothoida, consists of 54 species belonging to 18 genera, all of which are exclusively ectoparasites of mysid, euphausiid and decapod crustaceans (Boyko and Schotte 2013; Shields and Gómez-Gutiérrez 1996; Williams and Boyko 2012)
Seven dajid species have so far been recorded from Japan: Aspidophryxus japonicus Shimomura & Ohtsuka, 2011 from the mysid Holmesiella affinis Ii, 1937, Heterophryxus appendiculatus G
The present paper describes a new species of Aspidophryxus and is the second occurrence of the genus from Japan

Summary

Introduction

A family of the suborder Cymothoida, consists of 54 species belonging to 18 genera, all of which are exclusively ectoparasites of mysid, euphausiid and decapod crustaceans (Boyko and Schotte 2013; Shields and Gómez-Gutiérrez 1996; Williams and Boyko 2012). Seven dajid species have so far been recorded from Japan: Aspidophryxus japonicus Shimomura & Ohtsuka, 2011 from the mysid Holmesiella affinis Ii, 1937, Heterophryxus appendiculatus G.

Results

Conclusion