Modiolus undulatus   (Dunker)  (Mussel)
Organism information awaits expert curation
Class: Bivalvia

Image copyrights:Government of India

Size: 7.45-19.10 mm; length 27.25-34.35 mm; width 13-14.30 mm; height 9.35-12.65 mm

Color: Yellowish brown

Shell gibbous, oblong, semi-transparent, thin rather inequivalve; umbo not so prominent, anteriorly situated. Its upper margin strongly elevated at or near the middle and is sometimes subangulate, lower margin of shell straight or slightly concave, one of the two valves is slightly more inflated in some specimens. There are transversely striated costae in front of and below the umbo. Similar costae are present on the posterior edge of some of the shells and also sometimes along its whole length. The shell is yellowish green in colour with zig-zag purple lines which run transversely and are frequently interrupted and there are finer straight radiating lines of the same colour. Lines of both kinds frequently disappear ahnost completely on the lower half of the shell and the longitudinal ones are sometimes well developed in the posterior half. In some rare cases the entire surface with the exception of the extreme margin is suffused with purple pigmentation.

It very much resembles Modiolus striatulus but differs from it in having thin and fragile shell with reddish undulating markings on its surface, radiating striae towards anterior and posterior parts.

Synonym (s)
Valsella undulata Dunker 1856
Modiola chilkaensis Preston 1911
Modiola undulata var. crassicosta Preston 1914
Volsella undulata Dunker 1856
Modiola undulata var. crassicostata Preston 1914
Modiola undulata Annandale and Kemp 1916

Common Name (s)
Economic Importance and Threats

Habitat:  Coastal


• Orissa, Nalabana INDIA (Record: 1913)
• Orissa, Balugaon INDIA (Record: 1913, 1954, 1955)
• Orissa, Rambha INDIA (Record: 1913)
• Orissa, Off Samal Island INDIA (Record: 1913)
• Orissa, Kalidai Island INDIA (Record: 1954)
• Orissa, Kaliyugeswar INDIA (Record: 1973)
• Orissa, Brahmagiri INDIA (Record: 1984)
• Orissa, Sapara INDIA (Record: 1985)
• Orissa, Gollapara INDIA (Record: 1985)
• Orissa, Nuapara INDIA (Record: 1985)
• Orissa, Breakfast Island INDIA (Record: 1985)
• Orissa, Honeymoon Island INDIA (Record: 1985)
• Orissa, Samal Island INDIA (Record: 1985)
• Orissa, Malud INDIA (Record: 1985)
• Orissa, Palur Canal INDIA (Record: 1985)
• Orissa, Panchkudi INDIA (Record: 1985)
• Orissa, North Panth Nivas INDIA (Record: 1985)
• Orissa, Parikuda INDIA (Record: 1985)
• Orissa, Kalijai INDIA (Record: 1985)
• Orissa, Nalabana INDIA (Record: 1985, 1986)
• Orissa, Gopakuda INDIA (Record: 1987)
• Orissa, Malatikuda INDIA (Record: 1987)
• West Bengal, Kakdwip, Mainapara INDIA (Record: 01/02/1981)
• West Bengal, Port Canning INDIA (Record: 26/09/1984)
• West Bengal, South 24 Parganas INDIA (Record: 1992)
• Orissa INDIA (Record: 1992)
• Tamil Nadu INDIA (Record: 1992)
• Andhra Pradesh, Kakinada Bay INDIA (Record: 1991)
• West Bengal, Subarnarekha Mouth INDIA (Record: 07/2000-06/2001)
• West Bengal, Sankarpur INDIA (Record: 07/2000-06/2001)
• West Bengal, Sundarbans INDIA (Record: 1991)
• Orissa, Nimnashi INDIA (Record: 1987)
• Orissa, Pandanashi INDIA (Record: 1985)
• Orissa, Baradonta INDIA (Record: 1985)
• Orissa, Siar INDIA (Record: 1985)
• Orissa, Sidhakona INDIA (Record: 1985)
• Orissa, Birds' dropping Island INDIA (Record: 1985)
• Orissa, Off Kankarpara Island INDIA (Record: 1954)
• Orissa, Seruanadi INDIA (Record: 1913)
• Orissa, Cherriya Island INDIA (Record: 1913)
• Tamil Nadu, Kalpakkam INDIA (Record: 1987-1988)
• Tamil Nadu, Edaiyur Backwaters (Lat: 12.56) (Long: 80.18) INDIA (Record: 04/1988-03/1989)
• Andaman and Nicobar Islands, Galathea Bay (Lat: 6.75) (Long: 93.63) INDIA
• Andaman and Nicobar Islands, Great Nicobar INDIA

Literature Source(s)
  • Rao, NVS; Rao, KVS and Manna, RN (1995) Mollusca Wetland ecosystem series 1: Fauna of Chilka lake ZSI, Calcutta 391-468 Available at - NIO, Goa
  • Society for the Management of European Biodiversity Data (2009) World Register of Marine Species (WoRMS) Available at -
  • 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
  • Vijayakumar, R; Ansari, ZA and Parulekar, AH (1991) Benthic fauna of Kakinada bay and backwaters, east coast of India Indian Journal of Marine Sciences 20 195-199 Available at -
  • Khalua, RK; Chakravarty, G and Chakraborty, SK (2003) Annotated list of molluscs from the coastal tract of Midnapore District, West Bengal, India Journal of the Marine Biological Association of India The Marine Biological Association of India, Cochin 45(2) 245-249 Available at - NIO, Goa
  • 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
  • Rao, KS (1974) Other commercial molluscs The commercial molluscs of India Bulletin Of Central Marine Fisheries Research Institute CMFRI, Cochin 25 141-151 Available at -
  • Sasikumar, N; Rajagopal, S and Nair, KVK (1989) Seasonal and vertical distribution of macrofoulants in Kalpakkam coastal waters Indian Journal of Marine Sciences Scientific Publishers 18(4) 270-275 Available at - NIO, Goa
  • Rajagopal, S; Azariah, J and Nair, KVK (1990) Ecology of fouling organisms in Edaiyur backwaters, Kalpakkam Mahasagar- Bulletin of the National Institute of Oceanography NIO, Goa 23 (1) 29-41 Available at -
  • 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

Page last updated on:2012-07-19

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