Eremisopus, Wilson & Keable, 2002

Wilson, George D. F. & Keable, Stephen J., 2002, New Genera of Phreatoicidea (Crustacea: Isopoda) from Western Australia, Records of the Australian Museum 54 (1), pp. 41-70: 44

publication ID 10.3853/j.0067-1975.54.2002.1359

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Eremisopus   n.gen

Type Species. Eremisopus beei   n.sp.

Etymology. Eremisopus   is derived from the Greek (gender masculine) for “lonely isopod”, because this taxon has been found only in a single isolated stream near PAGO Mission, north of Kalumburu in the NW Kimberley.

Diagnosis. Pleonite 5 with dorsal median ridge. Pleotelson with dorsal median ridge and posterolateral ridges confluent with posterior margin; median lobe broad, with concave dorsal surface; postanal ridge triangular in ventral view, with robust setae at posterior apex; lateral lobes forming large vertical plates; dorsal uropod ridge curving strongly and extending posteriorly from uropods on pleotelson margin. Antennal flagellum proximal articles with dense cuticular hairs in male (fewer in females). Pereopod I dactylus distinctly shorter than propodal palm, propodal palm of male with approximately 30 robust setae. Pereopod V–VII basis with dorsal ridge plates as wide as basis shaft. Pereopod VII ischium dorsal ridge forming flange less than shaft width. Pleopods I–III protopods only with coupling hooks; pleopod II with lobe-like lateral epipod, appendix masculina shorter than endopod length, setose along entire margin. Uropod protopod dorsomedial plate higher than depth of protopodal shaft, with row of robust setae; rami distal tips pointed.

Remarks. Eremisopus   n.gen. shares several character states with Eophreatoicus   species including a plate-like ridge on the ischium of the posterior pereopods, a uropodal ridge on the pleotelson that curves smoothly toward the posterior margin, and a first pereopod with numerous conical stout setae and a dactylus shorter than the palm. Some, but not all, Eophreatoicus   species also have a dorsal midline ridge on the pleotelson, similar to Eremisopus   . A large postanal ridge of the pleotelson with stout setae is also present in both taxa, although more strongly developed in Eophreatoicus   . The two genera differ in the size of the dorsal plate on the ischium of pereopod VII, being smaller in Eremisopus   , as well as the presence of pleotelson lateral ridges in Eremisopus   .