Family JOEROPSIDIDAE Nordenstam, 1933

Rugojoeropsis rugosa

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Family JOEROPSIDIDAE Nordenstam, 1933

Introduction

The largest of three genera, Joeropsis (commonly misspelled Jaeropsis), comprises about 54 species mostly from the Southern Hemisphere in shallow-water marine habitats (Just 2001). The other two genera are confined to Australia and the species listed here.

Nordenstam (1933) diagnosed the family in detail as Jaeropsini. Sivertsen & Holthuis (1980) corrected the spelling of the family and genus names. Brief family diagnoses were provided by Menzies (1962) and Kensley & Schotte (1989), but Just (2001) gave much more detail and a discussion of history and important generic characters.

Diagnosis

Janiroidea with flattened body; lateral margins normally parallel, occasionally tapering posteriorly. Pereonites of subequal length, with truncate, entire or at most finely serrate, lateral margins covering coxae. All pereopods similar, slender, ambulatory, with 2 or 3 dactylar claws. Sessile eyes normally present in dorsolateral position on cephalon. Anterior margin of cephalon with strong concavity, or rarely without concavity. Pseudorostrum present, inserted into cephalic concavity, rarely joined along straight line. Pleotelson subequal in width to pereonite 7, with no free pleonites. Antenna 1 shorter than cephalon, peduncular article 1 expanded, longer than articles 2 and 3 combined; flagellum shorter than peduncle, with 2 or 3 articles, rarely 4 or 5. Antenna 2 geniculate, with peduncular article 6 and flagellum folding laterad and backwards under lateral expansion of peduncular article 5; first 4 peduncular articles short, article 4 more or less telescoped into 3, article 5 longer than 1–4 combined, greatly expanded laterally, article 6 much shorter than 5, generally widening distally; antennal scale absent; flagellum with enlarged, normally conjoint article 1. Mandible molar a long, slender, pointed projection; incisor of 5–6 large teeth, (occasional small accessory denticles not counted); lacinia mobilis absent; palp with 3 articles. Maxillipeds, palp with 5 articles, at least article 2 medially expanded. Pleopod 2 of male and female with longer or shorter lateral fringe of modified cuticular scales; pleopod 3 exopod 2-articulate, longer than endopod, with lateral fringe of modified cuticular scales, endopod with 3 plumose setae; pleopod 4 exopod vestigial. Uropods biramous, inserted ventrally on pleotelson normally within distinctive insinuation in pleotelson margin; peduncle usually broader than long and medially expanded; rami shorter than peduncle. Anus outside pleopodal chamber, between bases of uropodal peduncles, partly or entirely covered by male pleopod 1 or female pleopod 2 respectively. Oostegites on pereopods 1–5. Female spermathecal duct opening on anterior surface of pereonite 5, oviduct opening ventral on pereonite 5 mediad to coxa.