Joeropsis Koehler, 1885

Kensley, B & Schotte, M, 2002, New species and records of Asellota from the Indian Ocean (Crustacea: Peracarida: Isopoda), Journal of Natural History 36, pp. 1421-1461 : 1428

Genus Joeropsis Koehler, 1885

Joeropsis Koehler, 1885: 1 ; Kensley and Schotte, 1989: 87.

Diagnosis. Dorsolateral eyes present. Rostrum distinct, sometimes with ange of transparent scales. Antennule with basal article widest and longest, often with transparent ange of scales. Antennal peduncle articles 3–5 somewhat in ated, article 2 often with fringe of transparent scales; agellum of about six short articles. Pleopod 1 of male, rami fused, elongate, distally rounded. Pleon consisting of single shield-shaped segment. Uropodal protopod short, usually with acute or tooth-like mesiodistal angle, tucked into sockets on either side of narrowly rounded posterior pleonal margin; rami reduced to small setose lobes.

Remarks. Species of the genus Joeropsis are widespread in tropical and temperate waters, occurring primarily in shallow habitats. Most are small (less than 5 mm total length), and morphologically very similar, with mouthparts, pereonal and pleonal appendages showing little variation. Five characters which do vary have been used to separate species: degree of setation of the body; serration of the lateral margins of the cephalon; shape of the rostrum; presence or absence of a strong mesiodistal tooth on the uropodal protopod; serration of the lateral margins of the pleon. As with so many groups of crustaceans, species of Joeropsis can be easily separated when alive or freshly dead, on colour pattern alone. If the animals are preserved in alcohol, this pigmentation is lost with time.