The molluscan diversity is poorly documented in India, especially on the west coast. The major surveys are those of Abercrombie (1893), Melvill & Abercrombie (1892, 1893), Preston (1916), Melvill (1951), Hornell (1951), Patil (1952), Subrahmanyam et al (1949, 1951), Kundu (1965), Menon et al. (1970), and Apte (1992, 1993, 1997). However, most of the surveys were confined to parts of the Gulf of Kutch, Mumbai, Karwar and Kochi.
The East coast has been comparatively well documented (Preston, 1910, 1911; Gude, 1914; Preston, 1914, 1916; Hornell, 1921; Prashad, 1927; Crichton, 1941; Gravely, 1941, 1942; Ray, 1948; Satyamurthi, 1952, 1956; Subba Rao, 1971, 1977; Rajagopal & Mookherjee, 1978; Subba Rao, 1980; Rajagopal & Mookherjee, 1982; Subba Rao & Dey, 1984; Mookherjee, 1985; Subba Rao & Dey, 1986; Subba Rao & Surya Rao, 1993, and Apte, 2004).
To fill the lacuna in the knowledge of marine mollusca in India, the Ministry of Environment and Forests under the AICOPTAX initiated a data inventory studies in 2001.
The Bombay Natural History Society has been given the task of documenting molluscan fauna of Gujarat State on the west coast of India. Most of the earlier surveys in Gujarat were confined to parts of the Gulf of Kutch. During the present survey, efforts were made to cover Gujarat State district wise with at least two main collection sites. During the present survey, it was noticed that the molluscan fauna of the southern part of Gujarat is quite similar to that of Maharashtra. However, it changes considerably in the northern part of the Gujarat State, especially from the Gulf of Khambhat (Cambay) to the Gulf of Kutch. This area is especially interesting in biogeographical terms. In the north, the fauna is influenced by the Arabian Sea upwelling regime and there appears to be a dramatic faunal change from northern India across Makran and into the Arabian Gulf. The Indus fan is a large hydrographic influence, but we know little about its function to create a faunistic barrier or what special environment it creates.
a) Prepare the molluscan species inventory of Gujarat State; b) Identify potential habitats for conservation of Mollusca; c) Identify priority species for conservation; d) Assess values of molluscan diversity (ecological, edible, commercial, biomedical etc.); e) Identify species in wildlife trade; f) Identify main threats to the molluscan diversity.
Since 2001, BNHS has recorded over 400 species of molluscs with over 50 range extensions.