Enigmonia aenigmatica   (Holten,  1802) (Oyster)
Organism information awaits expert curation
Class: Bivalvia

Image copyrights: Toba aquarium

Size: length 13.63-45.50 mm; width 11.50-40.40 mm; height 3.60-8.70 mm

Color: The juveniles are red to purple in color, but when they reach the leaves of mangrove trees the color of the shell turns to golden.

Shell is thin, fragile, inequivalve, almost rounded. Right valve is bigger than the left. Muscle scars are well developed. Adductor muscle scar is single and smaller than the byssal retractor scars. There are three muscle scars in the left valve. Crurum oblique.

It is found attached to the trunks of mangrove plants. It attaches with its right valve and the umbo pointing downward to the exposed part of the trunk which receives the tidal splash. It is highly motile, and crawls from its initial settlement sites, which are intertidal on seedlings of mangrove trees and other hard substrates (unpublished observations), onto trunks and leaves of mangrove trees. The juveniles are red to purple in color, but when they reach the leaves of mangrove trees the color of the shell turns to golden. However, not all the animals reach the leaves, those on the trunk remain purple. Each time an individual moves from trunk or branch to leaf or leaf to trunk, the color of the shell will change and a record of the number of such movements will be left in the shell as bands of colored and colorless/golden shell layers, provided they stay on the substrate for long enough.

Synonym (s)
Tellina aenigmatica Chemnitz, 1795
Enigmonia aenigmatica Iredale, 1918
Anomia aenigmatica Subba Rao and Mookherjee 1975
Enigmonia aenigmatica Abbot and Dance, 1982
Aenigma convexum Koch, 1846
Aenigma corrugatum Koch, 1846
Aenigma reticulatum Koch, 1846
Anomia aenigmatica Holten, 1802
Anomia alfredensis Turton, 1932
Anomia curiosa Turton, 1932
Anomia farquhari Turton, 1932
Anomia naviformis Jonas, 1847
Anomia oblonga Turton, 1932
Anomia rosea Gray, 1825

Common Name (s)
Economic Importance and Threats

Habitat:  Demersal


• West Bengal, North 24 Parganas INDIA (Record: 1992)
• West Bengal, South 24 Parganas INDIA (Record: 1992)
• Orissa INDIA (Record: 1992)
• Maharashtra INDIA (Record: 1992)
• BANGLADESH (Record: 1992)
• MYANMAR (Record: 1992)
• Orissa, False Point INDIA (Record: 13/03/1964)
• Orissa, Puri INDIA (Record: 1991)
• Maharashtra, Mumbai INDIA (Record: 1991)
• West Bengal, Sajnatala INDIA (Record: 1992)
• West Bengal, Digha Coast INDIA
• Orissa, Mahanadi Estuary (Lat: 20.28) (Long: 86.70) INDIA

Literature Source(s)
  • 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
  • Subba Rao, NV; Dey, A and Barua, S (1992) Estuarine and marine molluscs Fauna of West Bengal Part 9 (State fauna series 3) ZSI, Calcutta 129-268 Available at - NIO, Goa
  • Raffles Museum of Biodiversity Research Available at - http://rmbr.nus.edu.sg/
  • Sealifebase Available at - http://www.sealifebase.org/
  • TOBA AQUARIUM Available at - http://www.aquarium.co.jp/index.html
  • Society for the Management of European Biodiversity Data (2009) World Register of Marine Species (WoRMS) Available at - http://www.marinespecies.org
  • 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
  • Dey, M and Mitra, A (2005) Molluscan community around Digha coast, West Bengal, India Journal of Environment and Sociobiology Social Environmental and Biological Association, Kolkata, India 2(1&2) 43-47 Available at - NIO, Goa
  • Zoological Survey of India (Eds.) (1998) Fauna Of Mahanadi estuary, Orissa Estuarine ecosystem series no 3 ZSI, Kolkata 1-218 Available at - ZSI, Pune

Page last updated on:2012-11-09

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