Family PLATYISCHNOPIDAE Barnard & Drummond, 1979

Tittakunara katoa

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Family PLATYISCHNOPIDAE Barnard & Drummond, 1979

Introduction

The Platyischnopidae are a small group of widely distributed shallow-water, benthic infaunal species closely related to phoxocephalin amphipods (Barnard & Karaman 1991). Platyischnopids are distinguished by their cone-shaped rostrum which apparently contains glandular tissue and specialised sensory setae. Four of the eight known genera and five of the 10 known species occur in Australian waters. Little is known of the behaviour, ecology or life histories of platyischnopids; Thomas & Barnard (1983) found some species to be micropredators. Barnard & Karaman (1991) present a key to all genera. Barnard & Drummond (1979) present a key to the Australian species.

Diagnosis

Head longer than deep; rostrum long; eyes well developed (round), obsolescent or absent. Body laterally compressed; smooth. Antenna 1 shorter than, subequal to, or longer than antenna 2; peduncle with many robust or slender setae; peduncular article 1 shorter than article 2; article 2 longer than article 3; article 3 shorter than or subequal to article 1; primary flagellum 5- or more articulate; callynophore present. Antenna 2 short or longer than body; peduncle with robust or slender setae; flagellum shorter than, as long as or longer than peduncle; 5- or more articulate; calceoli present. Mandible incisor dentate; lacinia mobilis present on both sides; molar non-triturating, fully setose. Maxilla 1 inner plate weakly setose apically; palp 1- or 2-articulate. Maxilliped inner plates reduced; outer plates large or small. Coxae 1–4 longer than broad, overlapping. Gnathopod 1 not sexually dimorphic; smaller (or weaker) than or subequal to gnathopod 2; chelate; coxa smaller than or subequal to coxa 2; carpus subequal to, or longer than propodus. Gnathopod 2 not sexually dimorphic; chelate; coxa smaller than or subequal to but not hidden by coxa 3; ischium short; carpus long, subequal to, or longer than propodus. Pereopod 3 coxa longer than broad; carpus shorter than propodus, not produced. Pereopod 4 coxa larger than coxa 3, with well-developed posteroventral lobe; carpus shorter than propodus, not produced. Pereopods 5–7 with many rows of facial and marginal robust setae or with many rows of marginal robust setae. Pereopod 5 shorter than pereopod 6; coxa smaller than coxa 4, without posterior lobe; basis expanded, subrectangular or subquadrate, with or without posteroventral lobe; carpus expanded, weakly expanded or linear. Pereopod 6 shorter than pereopod 7; basis expanded. Pereopod 7 longer than pereopod 5; basis expanded, with broad posteroventral lobe. Urosomite 1 longer or much longer than urosomite 2. Uropods 1–2 apices of rami with robust setae. Uropod 3 biramous; peduncle short; rami styliform; outer ramus longer than peduncle; inner ramus apically setose. Telson laminar; deeply, moderately or weakly cleft, emarginate or entire; longer than broad or as long as broad; dorsal robust setae present; apical robust setae present or absent.