Recruitment pattern and early growth of Crassostrea iredalei in Setiu Laggon, Terengganu

Abstract

The cup oyster, Crassostrea iredalei was abundant naturally in Setiu Lagoon, Terengganu. There is no study done on recruitment and growth of Crassostrea iredalei in Setiu Lagoon. Two designs of culture methods are presently to determine the significant difference of growth rate between natural spats (bottom tray) and natural culture (hanging rope). Growth was determined by measuring the width and length of spat every month (September 2006 to February 2007). The mean number of spat was found greatly on hanging rope rather than in sediment. Hanging collector has the variables spat number for each month. Growth rate (width and length per month) have shown significant different for both techniques. Tray spat were significantly slower growing than spat on rope collector. Mortality rates were higher in bottom tray where all the spats died on February. The mean spat sized was achieved to 1.833 cm± 0.115 (width) and 2.2 cm ± 0.6083 (length). Width and length increase was exponential for hanging spat. The final growth of spat has reached up to sized 3.5283 cm ± 0.863 (width) and 3 .175 cm ± 0. 7765 (length). The range width and length of the spat on shell collector after six month is 2.1 x 3.0 cm to 6.4 x 2.6 cm.