Pinnotheres placunae   Hornell & Southwell  1909 (Crab)
Organism information awaits expert curation
Class: Malacostraca

Female, dorsal view

Length of carapace: 6.25 mm
Breadth of carapace: 7.25 mm
Length of carapace: 7.5 mm
Breadth of carapace: 11.25 mm

Color (male): Light pinkish

In the female, the body is soft and membraneous. The carapace is broader than long, circular, smooth and flat. The antero-lateral angles, though rounded, are pronounced. The external maxillipeds have the antero-internal angles of the ischium-merus roundes; the dactylus does not extend to the apex of the propodus.
The legs increase in size posteriorly, except the last pair, which are smaller than the first. The dactyli of the last two pairs are one and half times as long as those of the first two, those of the last pair being more hairy at the tips. There is a thick tuft of hair at the distal end of the propodite of the last pair.
In the male, the carapace is smooth, and harder than in the female. The legs are slender. The first pair is about equal in length to the chelipeds, the second pair is longer than the first by slightly more than a thick tuft of hair at the distal end of the propodite of the last pair. The abdomen is narrow.
This species is similar to Pinnotheres similis Burger, which too lives in Placuna placenta, but differs from it in the following:
(1) The front is not setose
(2) There are no spinules on the dactylus of the last leg
(3) The proportions of the lengths of the legs are different.
The anterior male abdominal appendages are long, cylindrical and rod-like. Their tips are bent at the end in the shape of a claw, and bear coarse hairs near both margins.

Numerous specimens of both sexes, were found living as commensals within the mantle cavity of the bivalves Placuna placenta. The majority were found near the anus.

Synonym (s)
Pinnotheres placunae Hornell & Southwell 1909

Common Name (s)
Economic Importance and Threats



• Maharashtra, Mumbai INDIA
• Gujarat, Okha INDIA
• West Coast INDIA

Literature Source(s)
  • Chhapgar, BF (1957) Marine crabs of Bombay state Contribution No. 1 of the Taraporevala Marine Biological Station Marine Biological Station, Department of fisheries, Bombay 89 pp Available at - NIO, Goa
  • Society for the Management of European Biodiversity Data (2009) World Register of Marine Species (WoRMS) Available at -
  • Jeyabaskaran, R; Wafar, S and Wafar, M (2002) CD on Brachyuran Crabs of West Coast, India Available at -

Page last updated on:20-04-09

Back to Search