Septifer bilocularis   (Linnaeus,  1758) (Mussel)
Organism information awaits expert curation
Class: Bivalvia

Max. size: 5.0 cm SL

Color: Exterior of shell deep green, becoming brownish and paler towards the umbones. Interior bluish grey to purplish brown, white on the umbonal area.

Shell thick, elongate, variable in shape, roughly trigonal-ovate or trapezoidal in outline, markedly swollen and pointed anteriorly, rounded and somewhat compressed posteriorly. Umbones terminal, prominent, sharply tapering and ventrally recurved. Anterior margin reduced. Ventral margin long and usually broadly concave. Posterodorsal area somewhat expanded and laterally compressed. Outer surface of valves covered with numerous, densely set radial riblets slightly diverging on posterodorsal and posteroventral areas. Periostracum strong, tightly applied to shell. Hinge with a few small denticles under the umbo of each valve. A strong shelly ledge above the umbonal cavity, supporting the anterior adductor scar and expanded dorsally as a low ridge along the ligament. Internal margins finely crenulated throughout.

Synonym (s)
Mytilus nicobaricus Chemnitz, 1785
(Junior synonym)
Septifer pilosus (Reeve, 1858)
(Junior synonym)
Modiola subtriangularis Turton, 1932
Mytilus bilocularis Linnaeus, 1758
Mytilus nicobaricus Roding, 1798
Mytilus septulifer Menke, 1830
Tichogonia kraussii Kuster, 1841
Tichogonia wiegmannii Kuster, 1841

Common Name (s)
• Box Mussel
• Ledge Mussel (English)
Economic Importance and Threats

Habitat:  Reef Associated, Coastal
Trophic Level:  Consumer
Prey:  Plankton


• Andhra Pradesh, Off Visakhapatnam Coast (Lat: 17.7) (Long: 83.3) INDIA
• Gujarat, Gulf of Kachchh (Lat: 22.6) (Long: 69.5) INDIA
• Tamil Nadu, Tuticorin Fishing Harbour INDIA
• Tamil Nadu, Mandapam INDIA
• Palk Bay (Lat: 9.28) (Long: 79.13) INDIA (Record: 04/1994-09/1994)

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
  • Sarma, ALN (1977) The phytal fauna of Sargassum off Visakhapatnam coast Journal of the Marine Biological Association of India Marine Biological Association of India, Ernakulam, Cochin-682 011, India 16(3) 741-755 Available at - NIO, RC, Kochi
  • Subba Rao, NV and Sastry, DRK (2005) Fauna of Marine National Park, Gulf of Kuchchh (Gujarat) ZSI 79 pp Available at - NCL, Pune
  • Oliver, PG; Holmes, AM; Killeen, lJ and Wood, H (2004) Annotated checklist of the marine Bivalvia of Rodrigues Journal of Natural History Taylor and Francis 38 3229-3272 Available at -
  • Tan, KS and Kastoro, WW (2004) A small collection of gastropods and bivalves from the Anambas and Natuna Islands, south China Sea The Raffles Bulletin of Zoology 11 47-54
  • Ray, HC (1977) Contribution to the knowledge of the molluscan fauna of Maungmagan, Lower Burma (with descriptions of one new genus and species of the Family Turridae (Gastropoda) 8) Contribution to the knowledge of the molluscan fauna of Maungmagan, Lower Burma (with descriptions of one new genus and species of the Family Turridae (Gastropoda) 8) Indian Museum, Calcutta 1-150 Available at - Zoological Records (Burma marine)
  • Allen, GR (2005) Reef fishes of northwestern Madagascar RAP Bulletin of Biological Assessment 31 39-48
  • Sealifebase Available at -
  • Society for the Management of European Biodiversity Data (2009) World Register of Marine Species (WoRMS) Available at -
  • Kumar, RR; Edward, JKP and Jaikumar, M (2010) Macro benthic community structure on Tuticorin coastal waters, Gulf of Mannar,South East Coast of India World Journal of Fish and Marine Sciences IDOSI publications 2(1) 70-77 Available at -
  • Sundaram, KS; Sarvesan, R; Mohamed, KH and Shanbhogue, SL (1969) Catalogue of molluscs, prawns, stomatopods and marine algae in the reference collections of the central marine fisheries research institute Bulletin Of Central Marine Fisheries Research Institute CMFRI, Cochin 9 1-52 Available at -
  • Ramesh, DA; Jeyabaskaran, R and Pandian, ALP (1996) Gastropods and bivalves associated with reef building corals, Palk Bay, southeastern India Phuket Marine Biological Center Special Publication Phuket marine biology Center 16 257-260 Available at -

Page last updated on:2011-03-22

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