Family JANIRIDAE Sars, 1897

Notasellus australis

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Family JANIRIDAE Sars, 1897

Introduction

This cosmopolitan family is found in most benthic marine and some freshwater environments. Numerous species in at least 20 genera are known. The allocation of genera to this family and synonymy of many genera was discussed by Wolff (1962) but his work is now out of date. Wilson & Wägele (1994) have revised the family and discussed its relationships to some other asellote families. They diagnosed and discussed the genera. Wilson (1994) carried out a phylogenetic analysis, but concluded the family could not be redefined because "the data allow monophyly only under a broad taxonomic definition that includes acanthaspidiids, microparasellids, joeropsidids, and probably many other janioidean families". The family is certainly not monophyletic.

Many Australian species exist, but few are described. The following diagnosis is from Wolff (1962).

Diagnosis

Body oblong, depressed. Head and pereonites free, with the lateral parts lamellarly expanded in most genera and pereonites subequal in length. Pleon usually consists of 2 segments; when present, the first is narrow and inconspicuous, the second large and shield-shaped. Eyes often present, situated on upper surface. Antenna 1 almost always longer than antenna 2, with 6 articles in peduncle and with generally well-developed antennal scale. Mandible with palp, normally with well-developed molar process. Maxillipedal palp usually with article 3 in particular, expanded; as wide as or wider than endite. Pereopod 1 usually more or less prehensile; remaining pereopods ambulatory, of moderate and almost equal length. Dactylus almost always with 2 or 3 claws. Uropods on lateral or terminal margin, with peduncle, biramous or occasionally uniramous.