Haploniscus kensleyi, George, 2004

George, Robert Y., 2004, Deep-sea asellote isopods (Crustacea, Eumalacostraca) of the north-west Atlantic: the family Haploniscidae, Journal of Natural History 38 (3), pp. 337-373 : 351-352

Haploniscus kensleyi n. sp.

(figure 8)

Diagnosis. Haploniscus with body broader posteriorly between pereonites 5 and 7. Cephalon with a median projection, about as long as the anterior two pereonites combined. Pereonite 7 in female fused with the shield-like pleotelson. Antenna 1 with flagellum of five articles.

Material examined. Holotype: female, length 2.1 mm, maximum width 0.9 mm. USNM Cat No. 138673.

Type locality. R / V Eastward Sta. 7786, site Alpha-B over the Carolina upper slope .

Etymology. This new species is named in honour of isopodologist Dr Bryan Kensley of the National Museum of Natural History, Smithsonian Institution, Washington, DC.

Description of female. Body broader at pereonites 5 and 6, narrower anteriorly and posteriorly. Cephalon with rounded lateral and anterior margin, with a conspicuous median projection. Pereonites 1–3 subequal, pereonite 4 longer. Lateral suture well-developed between pereonites 4 and 5. Pereonite 5 the longest, and pereonite 6 the shortest of all pereonites. Pereonite 7 fused with pleotelson. Pleotelson shield-like, with posterolateral angles produced beyond the rounded apex.

Antenna 1 with peduncle of two articles, basal article globular and partly concealed by cephalon. Flagellum of antenna 1 composed of five articles. Mandible with a long, stout and truncated molar process; a row of three serrated and two long movable middle spines, incisor process narrow and trifid. Maxilliped with three coupling hooks on the endite and palp composed of five narrow articles, basal and terminal articles of similar width.

Remarks. This new species is one of the few deep-sea species of the genus Haploniscus from the north-west Atlantic; other north-west Atlantic species include H. curvirostris Vanhoffen, 1914 (also known from the Antarctic and south Atlantic deep sea), Haploniscus retrospinis Richardson, 1908 from 713 m off New England and Haploniscus spinifer Hansen, 1916 collected during the Danish Ingolf expedition, from Davis Strait. This species is somewhat similar to H. curvirostris , with posterolateral angles of pleotelson projecting beyond the apex, and in having the basal article of antenna 1 concealed by the cephalon, as shown in figure 9B. However, the shape of the pleotelson, fused pereonite 7 thus forming a shield, and the enlarged fourth pereonite are features that clearly distinguish H. kensleyi from H. curvirostris .