Scapharca inaequivalvis [Status Unaccepted]   (Bruguiere,  1789) (Clam)
Organism information awaits expert curation
Class: Bivalvia

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Size: Maximum shell length 9.5 cm, commonly to 8 cm.

Color: Outside of shell white under the blackish brown periostracum. Inner side whitish.

Shell thick and solid, inflated, inequilateral, roughly quadrate in shape with arcuate ventral margin and obliquely truncate posterior margin. It is slightly inequivalve, left valve distinctly overlapping the right valve ventrally and posteriorly. Cardinal area rather long and narrow. About 33 radial ribs (30 to 36) at each valve. Ribs are as wide as the interstices and granulated on left valve. Periostracum is well developed. Internal margins with strong crenulations corresponding with the external radial ribs. No byssal gape.

Synonym (s)
Anadara inaequivalvis (Bruguiere, 1789)
Scapharca cornea (Reeve, 1844)
Arca inaequivalvis Bruguiere, 1789

Common Name (s)
• Unequal Arc (English)
Economic Importance and Threats
Importance:  Commercial
(Exploited for food)
Cultured:  Yes

Habitat:  Sandy, Muddy


• Orissa, Ganjam Coast INDIA
• Andhra Pradesh, Godavari Estuary (Lat: 16.63) (Long: 82.3) INDIA
• Orissa, Mahanadi Estuary (Lat: 20.32) (Long: 86.75) INDIA
• Maharashtra, Mumbai (Lat: 18.98) (Long: 72.83) INDIA
• Gujarat, Pirotan Island (Lat: 22.62) (Long: 69.97) INDIA
• Tamil Nadu, Parangipettai Coast (Lat: 11.48) (Long: 79.77) INDIA
• Gujarat, Gulf of Kachchh (Lat: 22.6) (Long: 69.5) INDIA
• Tamil Nadu, Kundugal Point INDIA
• Orissa, Balaramguri INDIA (Record: 1973)
• Orissa, Chandipur INDIA (Record: 07/03/1969)
• Orissa, False Point INDIA
• Orissa, Konark INDIA (Record: 19/12/1962-20/12/1962)
• Orissa, Puri INDIA (Record: 15/11/1962)
• Orissa, Chhatrapur INDIA (Record: 24/11/1962)
• Tamil Nadu, Chennai INDIA
• Tamil Nadu, Krusadai INDIA
• Tamil Nadu, Tharangambadi INDIA
• Kerala, Kochi INDIA
• Maharashtra, Mumbai INDIA
• Gujarat, Pirotan Island INDIA
• Persian Gulf
• Gujarat, Saurashtra INDIA
• Tamil Nadu, Gulf of Mannar (Lat: 78.13) (Long: 8.58) INDIA (Record: 01/1994- 12/1995)
• Tamil Nadu, Gulf of Mannar (Lat: 79.5) (Long: 9.33) INDIA (Record: 01/1994- 12/1995)

Literature Source(s)
  • Tikadar, BK; Daniel, A and Subbarao, NV (1986) Sea shore animals of Andaman and Nicobar Islands The Director, ZSI, Kolkatta 188 Available at - ZSI, Pune
  • Subba Rao, NV and Dey, A (2000) Catalogue of marine molluscs of Andaman and Nicobar Islands Occasional paper no 187 Records of the Zoological Survey of India ZSI 1-323 Available at - NCL, Pune
  • (2001) Fauna of Godavari estuary, Andhra Pradesh Estuarine ecosystem series 4 ZSI, Kolkata 1-166 Available at - ZSI, Pune
  • Zoological Survey of India (Eds.) (1998) Fauna Of Mahanadi estuary, Orissa Estuarine ecosystem series no 3 ZSI, Kolkata 1-218 Available at - ZSI, Pune
  • Shanmugam, A; Rajagopal, S and Nazeer, RA Common bivalves of Parangipettai coast Available at - NIO, Goa
  • Ramakrishna; Sarkar, J and Talukdar, S (2003) Marine invertebrates of Digha coast and some recomendations on their conservation Records of the Zoological Survey of India ZSI, Kolkata 101(3-4) 1 Available at - NCL, Pune
  • Fernando, AS and Fernando, OJ (2002) A field guide to the common invertebrates of the east coast of India Centre of Advanced Study in Marine Biology 1-258 Available at - NIO, RC Kochi
  • Poutiers, JM (1998) Bivalves FAO species identification guide for fishery purposes. The living marine resources of the western central Pacific. Volume 1: Seaweeds, corals, bivalves and gastropods FAO, Rome 1 686 pp Available at -
  • Society for the Management of European Biodiversity Data (2009) World Register of Marine Species (WoRMS) Available at -
  • Rao, NVS; Rao, KVS and Maitra, S (1991) Marine molluscs State fauna series 1: Fauna of Orissa Zoological Survey of India, Calcutta Part 3 1-175 Available at - NIO, Goa
  • Available at -
  • Dholakia, AD (2004) Marine resources Fisheries and aquatic resources of India Daya publishing house 271-303 Available at - NIO, Goa
  • Hameed, PS and Somasundaram, SSN (1998) A survey of bivalve molluscs in Gulf of Mannar, India Indian Journal of Fisheries Indian journal of Fisheries for the Indian Council of Agricultural Research, Kochi, India 45(2) 177-181 Available at -

Page last updated on:2012-03-07

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