Natural bioactive compounds from some marine prosobranchs gastropod from gulf of mannar

Abstract

The environmental conditions such as temperature, oxygen, pH, salinity and also nutrients influence not only the composition of its biota but also the growth and distribution of species of flora and fauna. Extrinsic and intrinsic factors are known to influence the distribution and abundance of the screened Prosobranchs in the Gulf of Mannar. North east monsoon during November 2010 was responsible for rainfall at Tuticorin coastal region in Gulf of Mannar. Seasonal changes in rainfall influence the density of lower invertebrate population of the intertidal areas (Odum 3rd Ed., 1971). Atmospheric and water temperature fluctuated seasonally. The low temperature could be due to strong land breeze, rainfall, land run-off, and cloudy sky as reported by Ananthan (1994). The temperature variation is one of the factors in the coastal estuarine system, which may influence the physico-chemical characteristics and also influence the distribution and abundance of flora and fauna. Dissolved oxygen content showed seasonal fluctuation, and it varies due to photosynthesis and respiration by organisms. Percent saturation of oxygen depends strongly on temperature as cold water holds more oxygen. The highest level of dissolved oxygen observed during monsoon might be due to phytoplankton production and photosynthesis as reported by Santhosh Kumar and Perumal (2011). An earlier report from these areas coincides with the present study, revealing the high contents of dissolved oxygen during monsoon newline