Journal of the Marine Biological Association of India

Biodiversity and distribution of marine gastropods (Mollusca) during pre- and post-monsoon seasons along the Goa coastline, India

Volume 55 Issue 1

Anuradha David

doi: 10.6024/jmbai.2013.55.1.01720-03

Abstract

Biodiversity and distribution of different gastropod species was studied during pre- and post- monsoon seasons in sub-and intertidal zones from 16 sampling sites located in the northern and southern regions of the Goa coastline, India. Each site was surveyed twice during the pre-monsoon and twice in the postmonsoon season. A set of 2,493 specimens, 86 species, 51 genera, and 24 families were identified during the sixteen surveys that were conducted, four each in the pre- and post-monsoon season during January 2008 to September 2009. Species abundance was higher in rocky inter-tidal zones when compared with sandy and or sub-tidal zones. Shannon-Weiner biodiversity index (H’) ranged from 2.1749 in the pre-monsoon season to 5.7641 during the post-monsoon months. Species richness (d) was the highest in Vacra and the lowest in Velsao during the
pre- and post monsoon seasons. Peilou’s indices recorded higher species evenness in the post-monsoon months in all the sampling sites. The highest number of species/individuals was obtained in Vacra (63/218) and the lowest in Miramar (13/74) respectively. A significant increase (P<0.001) was observed in the total number of individuals collected month wise in the pre- and postmonsoon seasons. Anjuna, Candolim, Sinquerim in north Goa and Betul, Palolem and Vacra in south Goa recorded more than 50 species whereas, less than 15 species were found in Dona Paula, Miramar (north Goa) and Velsao, Colva (south Goa). The highest number of individuals collected belonged to two families namely, Turritellidae and Trochidae. The results of this study indicate that the coasts of Goa are known to be a haven for gastropod fauna and needs to be protected to promote the conservation of this vulnerable resource.

Keywords

Gastropoda, Mollusca, spatial distribution, tidal zones, seasonal variations

Date : 30-04-2013