Population of modiolus spp. in the ıntertidal rocky coastline of pudhumadam, gulf of mannar

Abstract

The Gulf of Mannar falls in the Indo-Pacific region, considered to be one of world's richest marine biological resource regions. This is considered a hyper fragile environment, inhabiting all types of flora and fauna. Intertidal rocky coastlines are heterogeneous environments that support a wide variety of living forms. In these systems, organisms are distributed in a particular way, occurring at specific levels along the vertical axis, from the lower to the upper shore. Pudhumadam are the distinguished area of intertidal rocky shorelines in the Gulf of Mannar. Horse mussel Modiolus spp. belongs to the family Mytilidae. Studies on the distribution of individual numbers of Modiolus spp. in the intertidal rocky shore regions of Pudhumadam coast (Lat 09º16.26' N and Lon 94º12.88' E) near the Ramanathapuram district were carried out from August to October period in 2009 and 2010. Sampling plots were laid in 5 sites at an interval of 200 meters in 1 kilometer stretch of the coast using 1m2 quadrate method and mean (± SD) number of Modiolus spp. was estimated at 1356.45 and 1368.63 in 2009 and 2010 respectively. 0.12% increase was noted during 2010 when compared from 2009.