Family EXPANATHURIDAE Poore, 2001

Eisothistos sp.

© Copyright from Poore unpublished.

Museums

Regional Maps

• Expanathuridae Poore, G.C.B. 2001. Families and genera of Isopoda Anthuridea. Crustacean Issues 13: 63-173 [97].

Introduction

Expanathurids are distinguished from anthurids which they superficially resemble by the absence of statocysts, usually free pleonites, and the primitive condition of the maxilliped (presence of an endite and palp of five articles), anterodistal serrate setae on the propodus of pereopod 7, and the weakly operculiform pleopod 1. Some genera have a highly ornamented telson and uropodal margins not seen in other families (Poore, 2001; Poore & Lew Ton, 2002). The Expanathuridae are on first impression a heterogeneous family, but this is less apparent when the highly derived genus Eisothistos is ignored. Characters which unite the remaining genera include: absence of statocysts, presence of a maxillipedal endite and palp of five articles, anterodistal serrate setae on the propodus of pereopod 7, and the weakly operculiform pleopod 1. Some genera have highly ornamented telson and uropodal margins (not seen in other families).

The family is most diverse in the tropics but occurs also in southern temperate areas. Nothing is known of its biology. Poore (2001) provided a key to genera and listed all the species.

Diagnosis

Body 10–15 times as long as wide, non-males rarely more elongate (pereonite 7 wider than long, much shorter than pereonite 6); pleonites with plumose setae on margins of epimera or posterior margins of pleonite 5 and sometimes pleonite 4; pleonites 1–5 together not more than twice as long as wide; pleonites 1–5 free and articulating, or fused; telson statocysts absent. Antennal flagellum of fewer than 10 articles, shorter than peduncle, or of numerous articles. Mouthparts not produced anteriorly. Mandible tapering and incisor simple, or compact and with weakly-toothed transverse incisor (rarely). Maxillipedal palp narrow and tapering distally to rounded apex (c. 3 times as long as wide), or reduced, digitiform (Eisothistos). Pereopods 2–3 carpus not or weakly produced posterodistally. Pereopod 7 propodus anterodistal serrate setae present. Pleopod 1 exopod and endopod together weakly operculiform, or pleopod 1 exopod operculiform alone (Expanathura only).

General References

Poore, G.C.B. 2001. Families and genera of Isopoda Anthuridea. Crustacean Issues 13: 63-173

Poore, G.C.B. & Lew Ton, H.M. 2002. Expanathuridae (Crustacea: Isopoda) from the Australian region. Zootaxa 82: 1-60

History of changes