Australian Isopoda: Families

S.J. Keable, G.C.B. Poore & G.D.F. Wilson


Expanathuridae Poore, 2001

Expanathuridae Poore, 2001a: 119.

Description. Body. Body shape without loss or gross modification of appendages on one side of the body; in dorsal view without peduncular articles of antenna 1 or 2 contiguous with coxal margins.

Head. Head not capable of lateral rotation (laterally encompassed, abutting or fused to pereonite 1). Antenna 1 inserting on head anteriorly and/or dorsally to antenna 2, minute or well developed; not as follows: reduced to 2 articles with second article expanded and scalloped. Antenna 2 well developed; flagellum of fewer than 10 articles, shorter than peduncle, or of numerous articles, longer than or shorter than peduncle. Mouthparts not forming suctorial cone or proboscis; not produced anteriorly. Mandible not projecting anteriorly and together forceps-like; tapering, with simple incisor, or compact, with weakly-toothed transverse incisor (rarely); palp present, or absent. Maxilliped palp narrow and tapering distally to rounded apex (c. 3 times as long as wide) or reduced, digitiform, with 5 free articles or with 2 or more articles fused; endite reaching palp article 3 or absent or obsolete.

Pereon. Pereonites 6-7 pereonite 7 distinct dorsally, free. Pereonite 7 wider than long, much shorter than pereonite 6 (body 10-15 times as long as wide, females and juveniles rarely more elongate). Pereopods 6-7 pairs readily apparent; 1-3 or 1-7 not prehensile. Pereopod 1 propodal palm without proximal tooth (palm more or less continuous with that of carpus). Pereopods 2-3 carpus not or weakly produced posterodistally; propodus with 1 robust seta in addition to posterodistal robust seta, or with posterodistal robust seta only, or without posterodistal robust seta. Pereopods 4-7 propodus with more than 1 robust setae in addition to posterodistal robust seta, or with posterodistal robust seta only. Pereopods 5-7 without flattened setose articles andor dactyls modified or absent. Pereopod 7 propodus anterodistal serrate setae present.

Pleon / Pleotelson. Pleonites 1-5 free and articulating, or fused; together 2 times as long as wide (or less). Pleonites 4-5 with plumose setae on margins of epimera or posterior borders of 5 or 4-5. Pleopods 5 pairs present; with pleopod 1 exopod and endopod together weakly opercular, or with pleopod 1 exopod opercular alone (Expanathura only). Pleopod 2 of males not consisting of an enlarged peduncle with a geniculate endopod and a small muscular exopod. Pleotelson statocysts absent. Uropods positioned proximally on pleotelson; distinct from pleopods, not forming operculum over pleopodal chamber (although may be folded ventrally below pleotelson). Peduncle not forming an elongate clavate article with rami reduced or absent. Endopod not claw-like (acute and recurved) andor posteroventral in position. Exopod folded dorsally over pleotelson.

Distribution and generic composition. See Kensley et al. (1996).



Cite this publication as: 'S.J. Keable, G.C.B. Poore & G.D.F. Wilson (2002 onwards). 'Australian Isopoda: Families. Version: 2 October 2002. http://crustacea.net'.