A New Tantulocaridan (Crustacea : Maxillopoda) Parasitic on Calanoid, Harpacticoid and Cyclopoid Copepods

Abstract

Several life-cycle stages of a new genus of Tantulocarida (Crustacea: Maxillopoda), parasitic on three orders of copepods, are described from Okinawa, South Japan. This is the first record of a tantulocaridan on cyclopoid and calanoid hosts. Nipponotantulus heteroxenus n. gen., n. sp. was also found on at least four families of harpacticoid copepods (including both interstitial and epibenthic species), indicating its low level of host specificity. Nipponotantulus is placed in the Basipodellidae on account of the male trunk sac formation and both the setation and segmentation of the thoracopods. It is probably closest to Stygotantulus with which it shares the structure of the sixth thoracopod, but differs in the absence of a medial endite on thoracopod 1, the number of lamellae on the abdomen and the modified medial setae on the caudal ramus.