Jonas choprai   Serene,  1971 (Crab)
Organism information awaits expert curation
Class: Malacostraca

Image copyrights: The Marine Biological Association of India

Carapace is oval in shape and is about 1.4 times longer than broader. The dorsal surface does not have hair and is concave transversely and longitudinally. The basal antennal segment is granulated with two sharp tubercles on the outer distal surface while the first antennal segment reaches tip of the inner supraorbital tooth. Eyes are relatively larger and completely filling the orbits. The cervical groove and the grooves covering the gastric, cardiac and intestinal regions are quite distinct.
The bifurcated rostrum is prominent, the base of which is relatively narrow. Rostral teeth are short and separated by a deep ā€˜Uā€™ shaped notch. Broad deep ā€˜Uā€™ shaped notch separate the rostrum from the inner supraorbital tooth. The margin of the supraorbital region is granulated with two distinct notches. The inner tooth is very long which extends beyond the tip of the rostrum which is gently curved, when viewed laterally. The outer tooth is distinct. The inner supraorbital margin is also granulated and the tooth in the inner orbit is very strong and is shorter than the inner supraorbital tooth when viewed from above. The third maxillipeds are relatively elongated and the outer surfaces are granular.
Five pairs of thoracic legs are well developed. The first pair of legs is chelate in nature and subequal. Granules are present on the inner and outer surfaces of all segments. A small tubercle is present on the inner distal angle of basis-ischium. Merus not relatively short, dorsal margin has 7 sharp spines, the size of which increases from middle of merus to distal. Ventral margin of merus granulated with anteriorly directed distal spines which are sharp. Subtriangular carpus with long spine in the inner distal angle. One short sharp tooth and one sharp recurved spine are present respectively on dorsal margin and median distal surface. Fingers of cheliped are shorter than palm and the tips of fingers are curved. Cutting edges have blunt teeth and denticles. Numerous small sharp granules present on dorsal surface of dactylus. Lower side of hand has a row of closely packed small rounded granule resembling stridulatory ridge. Numerous sharp slightly recurved spines and tubercles are present on dorsal margin of palm. Ventral margin of palm with numerous granules and tubercles of varying sharpness. Median surface of palm has several sharp tubercles.
Among the walking legs, the fourth leg is the largest followed by second. Three distinct ventral spines are present on subdistal region of the merus of fourth leg. However, spines are not present on merus of other legs. Three subdistal ventral spines present on basis-ischium of fourth leg and the outer surface is with scattered small granules. The above segment in other legs is unarmed. Dactylus of ambulatory legs 1-3 is styliform and slightly compressed laterally. Dactylus of last leg is distinctly spatuliform. Lateral margin of all legs with setae.
The abdomen is short with six segments followed by the telson. The tip of telson is rounded and the lateral margins are not concave. In segments 2 and 3, the lateral surfaces are granulated. Segments are trapezoidal. Segment 1 is with small rounded granules on the median distal margin. The appendages on abdomen are setose and properly developed. Five pairs of pleopods are present. While the first pair is uniramous, the remaining ones are biramous.

Synonym (s)

Common Name (s)
Economic Importance and Threats



• Tamil Nadu, Parangipettai (Lat: 11.48) (Long: 79.76) INDIA (Record: 12/2006) (Depth: -(60-70) mts)

Literature Source(s)
  • Manokaran, S; Khan, SA; Lyla, PS and Murugan, S (2008) First record of brachyuran crab Jonas choprai Serene, 1971 (Crustacea: Decapoda) in Indian waters at Parangipettai, southeast coast of India Journal of the Marine Biological Association of India The Marine Biological Association of India, Cochin, India 50(1) 117-118 Available at - NIO, Goa
  • Society for the Management of European Biodiversity Data (2009) World Register of Marine Species (WoRMS) Available at -

Page last updated on:2010-11-15

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