General Description

Rostrum variable, with mid-dorsal spine at base, extending well above eye and as a deep blade between eyes anteriorly, sometimes toothed distally; not so deep in male. Carapace smooth with single supraorbital spine. Mandible with 2-articled palp, with incisor process. Fifth segment (carpus) of second leg (pereopod 2) with 7 articles. Maxilliped 3 without exopod. Legs (pereopods) without gills (arthrobranchs). Abdominal somite 6 without articulating posterolateral corner. The shape of the distinctive rostrum is variable, much deeper in females than males. The colour, green or yellowish matches that of the algae or seagrass in which it is found. Up to 2 cm long.

Biology

The shapes of the rostrum, variously blade-like and often elevated with the carapace well above the eyes, make this a bizarre shrimp. The rostrum is deeper in males than in females but has a small spine at its base in both sexes. Individuals may be green or yellowish, matching the particular alga in which they live.

Distribution

East Indo-west Pacific Oceans including southern Australia.

Habitat

Low intertidal, to 56 m depth.

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