MORPHOLOGICAL MEASUREMENT AND ABUNDANCE OF MANGROVE CLAM (Geloina expansa) AND ITS SEDIMENT GRAIN SIZE PREFERENCES AT PULAU SUTUNG AND PULAU BUSUNG, SETIU WETLANDS, TERENGGANU

Abstract

Geloina expansa is an infaunal filter-feeding clam species found in mangrove forest. They are important for humans and aquatic ecosystem. Not much information about morphological measurement, abundance and sediment grain size at Pulau Sutung and Pulau Busung. This study aims to determine the shell size measurements, the abundance and the composition of sediment grain size in these sites. Line transects were used for samples and sediment collection in a plot at Pulau Sutung and Pulau Busung. Twenty samples from each site were measured. The grain size and total carbon percentage were obtained using sieve shaker and ignition method. Independent t-test was conducted using SPSS for abundance density and measurements between two sites. 155 specimens (Pulau Sutung = 90; Pulau Busung = 65) were collected. However, abundance density between the two sites were insignificant. The most dominant grain size in Pulau Sutung is C500 whereas VC1000 is dominant in Pulau Busung. Mean shell length (= 55.35mm ± 6.39) and height (= 52.51mm ± 6.14) in Pulau Busung were greater than in Pulau Sutung (= 53.21mm ± 6.39; = 51.10mm ± 6.49), respectively. But mean shell width in Pulau Sutung, (= 31.30 mm ± 3.20) is greater than in Pulau Busung (= 31.19mm ± 4.05) but measurements were insignificantly different between the sites. This result will be useful to establish a baseline of data and also for the management and sustainability of the species. Future studies must be done by considering water parameter and collecting more samples from more site in Setiu Wetlands.