Pachycheles natalensis   (Krauss,  1843) (Crab)
Organism information awaits expert curation
Class: Malacostraca

Size: 3-4.75 mm (male), 2.5-2.75 (non-ovigerous female), 3.5-5 mm (ovigerous female); length of carapace 4.5 m, breadth of carapace 4.75 mm.

Color: Greenish brown.

Carapace broader than long in males, more or less convex, with no hairs on dorsal surface but with minute plications or rugae and with minute hairs arranged in lines on the epimeral regions, the rugae on the frontal region are broken and crowded, in the remaining area they are small and scattered, urogastric and cardiac regions almost smooth; front almost straight or slightly convex in the dorsal view, rostrum bent downwards so that in the frontal view, the front appears to be trilobed; outer orbital angle produced into a small but distinct tooth; epimera composed of two pieces, one large and the other small.
Antennule: Basal segment a little broader than long, ventral surface with a granulated ridge, its anterior margin with 3 or 4 minute teeth on the inner side, 2 such teeth on the outer angle, rest of margin minutely undulated.
Antenna: First segment much broader than long with acuminate edge on upper margin; second segment with a single tubercle on upper margin; upper margin of third segment almost smooth except for a few granules; fourth segment short and smooth.
Walking legs: Slightly striated and with few scattered hairs; propodus with 4 movable spinules of which 2 are on the posterior margin and the other 2 at the distal end of the margin, but on either surface; dactylus with 3 movable spinules which increase in size distally, tip a claw-like simple spine.
Telson: 5-plated, central piece being fairly large and broad.

Synonym (s)
Pachycheles sculptus Ortmann, 1894
Porcellana natalensis Krauss, 1843
Pachycheles natalensis Stimpson, 1858
Pisosoma natalensis Paulson, 1875
Pisosoma sculpta Gravely, 1927
Pachycheles natalensis Haig, 1964

Common Name (s)
Economic Importance and Threats

Habitat:  Rocky, Coastal


• Maharashtra, Ratnagiri INDIA
• Tamil Nadu, Gulf of Mannar INDIA

Literature Source(s)
  • Lewinsohn, C (1979) Researches on the coast of Somalia. The shore and the dune of Sar Uanle. 23. Porcellanidae (Crustacea Decapoda Anomura) Monitore Zoologico Italiano Supplemento 12 (6) 39-57 Available at - Zoological Records
  • Society for the Management of European Biodiversity Data (2009) World Register of Marine Species (WoRMS) Available at -
  • Siddiqui, FA and Kazmi, QB (2003) A checklist of marine anomurans (Crustacea: Decapoda) of Pakistan, northern Arabian Sea Memoirs of Museum Victoria 60(1) 87-89 Available at -
  • Sankolli, KN (1966) On the Porcellanidae (Crustacea-Anomura) of Ratnagiri along the west coast of India Proceedings of Symposium on Crustacea Marine Biological Association of India, Mandapam Camp Part-I 295-313 Available at - NIO, Goa

Page last updated on:2010-11-04

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