Hansenium, Serov & Wilson, 1995

Serov, Peter A. & Wilson, George D. F., 1995, A review of the Stenetriidae (Crustacea: Isopoda: Asellota), Records of the Australian Museum 47 (1), pp. 39-82 : 72-73

Hansenium n.gen.

Type species. Hansenium hanseni ( Nobili, 1906 ).

Species included. See Table 1 .

Etymology. Hansenium is named in honor of H.J. Hansen, who provided the first definitive work on the Stenetriidae early in this century. The gender is neuter.

Diagnosis. Head with reduced lateral and antennal spines; antennal spines rounded to pointed, longer than pointed lateral spines. Rostrum short, broad and apically flattened, slightly longer than antennal spines. Antennular flagellum with 8-14 articles. Antennal article 1 lateral spine much reduced or absent. Maxilliped endopodite distal margin with 6 fan setae. Pereonites with angular margins on pereonites 1-4; pereonite 1 longer than remaining pereonites; single and double coxal spines on anterior pereonites. Pereon elongate, anterolateral corners of pereonites 1 and 2 in females with large unfused coxal extensions. Pereopod I with large, robust dactylus twice as long as propodal width; propodus reduced, palm serrate in both sexes, and with large terminal spine in males. Male pereopod I carpus lateral margin extended and serrate. Pleopod 11 appendix masculina elongate with blunt distal tip; tip with ring of cuticular hairs; exopod subapical with large protopodal apical extension. Pleotelson with 2 free pleonites. Pleotelson elongate with prominent posterolateral spines; postanal region smoothly rounded.

. Remarks. The genus Hansenium is most closely related to Stenetrium sensu stricto in overall morphology but can be distinguished most prominently by the large, pointed extended carpus that participates in grasping with an elongated dactylus. Hansenium also has large reniform eyes, reduced lateral spines and a broad short rostrum. A correction is made to the nomenclature of the species described as S. caicosensis Kensley & Heard, 1991 by changing it to H. caicosense , in order that the species name is consistent with the gender of the genus, i.e. neuter.