Charybdis (Charybdis) goaensis     (Crab)
Organism information awaits expert curation
Taxonomy
Kingdom:Animalia
Phylum:Arthropoda
Class: Malacostraca
Order:Decapoda
Family:Portunidae

Description
Size: Carapace length 12.80 mm (male), 15.10 mm (female); extreme width of carapace 24.32 mm (male), 24.52 mm (female)

Color: Carapace light brown over tomentose regions, polished surfaces of granular transverse ridges and regional tuberosities dark brown; pale brown to offwhite ventrally. Chelipeds dark brown with whitish tips; other pereiopods light brown.

Carapace evenly tomentose/pilose, with the exception of transverse ridges and swellings. Frontal margin cut into six teeth (excluding inner supra-orbital angles), median frontal teeth bluntly triangular, projecting beyond broadly rounded sub-medians, laterals triangular, narrowest, separated from submedians by wide, U-shaped notch. Orbits with strong dorsal inclination; major orbital diameter two-fifths to nearly half of the inter-orbital space. Inter-orbital space almost one-quarter the carapace width. Fronto-orbital margin almost half the carapace width; antero-lateral margins oblique and more or less arched. Infra-orbital lobe with row of granules on frontal margin. Antennae fold transversely. Basal antennal joint with smooth granular ridge, its prolongation in contact with front, thus excluding antennal flagellum from orbit. Merus of third maxilliped with outer distal angle produced sideways. Antero-lateral margin of carapace moderately arched, cut into six serrated teeth separated by wide notches.
First tooth slightly notched, second and third sub-equal, blunt pointed with serrated margins, fourth and fifth wider and spiniform, sixth tooth greater than twice the length of the preceding five and laterally directed. Posterior margin of carapace slightly curved, forms a curve with the postero-lateral margins of carapace. Transverse ridges distinctly granular, two proto-gastric, one meso-gastric, a medially divided meta-gastric, and epibranchials along the level of the last antero-lateral teeth; frontal ridge obsolete. No transverse ridges beyond the level of the last antero-lateral teeth; prominent tuberosity on cardiac region covered with densely spaced small granules. Surface of transverse ridges and tuberosities more or less devoid of tomentum.
Chelipeds sub-equal in both sexes, rough, tomentose, a little less than twice the carapace length. Right cheliped larger in male, left cheliped larger in ovigerous female. Upper surface of merus granular with two well-developed spines and five to six granules on its anterior margin; no spine on posterior margin. Carpus with tuberculated upper surface bears one large spine on its inner angle and three small spines on outer angle. Manus tumid, five costate, with five spines on its upper surface; two blunt spines on distal margin immediately posterior to articulation with dactylus; two well-developed spines in the middle of upper surface trailed by coarse granular costae; fifth spine on the posterior margin just anterior to articulation with carpus; outer surface with three smooth costae, the lowermost reaches the tip of the dactylus. Dactylus smooth, strong, and slender with curved tips, longer than manus. Ambulatory legs long, slender; third pair longest, although shorter than the chelipeds. Dactyli and propodi of first three pairs of legs covered with densely packed bristles on both anterior and posterior margins, carpus and merus bear bristles only on posterior margin. Posterior margin of propodus and carpus of natatory leg smooth, merus with prominent spine on its postero-distal margin.
Thoracic sternites and abdominal cavity in male sternum finely granular. First three thoracic sternites narrow, sutures 1/2 and 2/3 prominent. Suture 3/4 wide and shallow. Sternite 4 widest, medially divided by a shallow anterior extension of abdominal cavity. Abdominal cavity commences from posterior portion of sternite 4 and covers sternites 5_8. Deep groove along abdominal cavity medially divides sternites 5_8. Granule of abdominal lock located immediately anterior to suture 5/6. Thoracic sternites in female specimens similar to those in male. Sixth abdominal segment in males broader than long, its sides parallel over less than half their lengths and then gradually converge distally; basal margin slightly convex, distal margin concave. G1 L-shaped, its distal tip short, stout, with a slight bend, reaches sixth thoracic sternite; membrane commences shortly behind the tip; outer row of bristles commences close to distal tip and terminates in the neck region; bristles clumped towards the distal end and sparsely placed towards the neck; inner row of 4_5 bristles very sparsely placed commencing distantly from distal tip and terminate before outer row of bristles; bristles on abdominal margin randomly and very widely placed.

Females exhibit dimorphism in abdominal shape; immature females with narrow, triangular abdomen, wide watch glass-shaped abdomen in ovigerous female. Female gonopore slightly reniform, located on thoracic sternite 6, posterior to suture 5/6 and corresponding to the bases of second pair of pereiopods.


Synonym (s)

Common Name (s)
Economic Importance and Threats

Ecology

Biogeography


• Goa, Zuari Estuary (Lat: 15.41) (Long: 73.81) INDIA (Record: 29/09/2006)
• Goa, Zuari Estuary (Lat: 15.41) (Long: 73.85) INDIA (Record: 29/09/2006)

Literature Source(s)
  • Padate, VP; Rivonker, CU; Anil, AC; Sawant, SS and Krishnamurthy, V (2010) A new species of portunid crab of the genus Charybdis (De Haan, 1833) (Crustacea: Decapoda: Brachyura) from Goa, India Marine Biology Research Taylor & Francis 6(6) 579-590 Available at - http://dx.doi.org/10.1080/17451000903505608
  • Society for the Management of European Biodiversity Data (2009) World Register of Marine Species (WoRMS) Available at - http://www.marinespecies.org

Page last updated on:2010-12-02

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