Study on population dynamic of gastropod, Telescopium telescopium and faunus ater in the mengrove area of Setiu Wetland, Terengganu

Abstract

The population dynamic of Faunus ater and Telescopium telescopium were investigated in the mangrove area of Kampung Pengkalan Gelap, Setiu Wetland, Terengganu from April 2012 to March· 2013. Relationship between shell length and fresh weight were determined monthly while the length and dry weight relationship were examined for every three months which were in June, September, December 2012 and March 2013 and it only for 30 individuals from various sizes. The length of Faunus ater was range from 0.3 to 7 .8 cm while for the Telescopium telescopium were range form 1.3 -8.9. Annually, the length-weight relationship of Faunus ater was in the form of Log W = -0.789 + 2.321 * Log L, while in exponential form, the equation was in the form of W = 0.163 L 2321 • The length-weight relationship of Telescopium telescopium was in the form of Log W = -2.54 + 2.267*Log L, while in exponential form, the equation was in the form of W = 0.557 L 2·267 • Overall, both species of gastropods possessed the negative allometric growth where as b < 3. The von Bertalanffy growth function (VBGF) was applied on a length-frequency data of the both species. The growth parameters were examined using electronic length-frequency analysis (ELEF AN) in "FiSAT II" software. The value of asymptotic length (Loo) and growth coefficient (.K) of the von Bertalanffy growth function (VBGF) for Faunus ater were at 10.50 cm and 0.69 year-1 and Telescopium telescopium were at 9.45 cm and 1.500 year-1 respectively. These indicate that Telescopium telescopium growth faster than Faunus ater.