Length weight relationships and fecundity estimates of long-spined Sea Urchin, Diadema setosum, from the Pulau Pangkor, Peninsular Malaysia

The present study is an attempt to describe the size frequency distribution, length weight relationships and fecundity estimates of long-spined Sea Urchin, Diadema setosum from the Pulau Pangkor, Peninsular Malaysia. In total 101 specimens of D. setosum were collected from the inter-tidal reef of Pulau Pangkor of Parek during the breeding season in May–August, 2010. Individual total length (TL) was measured using digital slide calipers and individual body weight (BW) was taken using a digital balance. Mean length of D. setosum was estimated as 59.66 mm and the mean weight was 101.68 g. Among the 101 specimens, 52 were males and 49 were females, indicating a sex ratio of male to female of 1:0.94. The logarithmic form of length-weight relationship of D. setosum was Log W = −1.3977 + 1.9049*Log TL, while the exponential form of equation obtained for the length-weight relation was W = 0.04*TL^1.9049. The value of regression co-efficient (r²) estimated for the species was 0.63. The mean fecundity was estimated at 7,313,600 (±567,992) with a range between 6,290,000 and 7,980,000 eggs. Analysis of the relationship between the absolute fecundity (F) and total length (TL), and also between the fecundity and drained body weight (DW), revealed a linear regression model with a positive and significant relationship. This study presents results on the total length-body weight relationships and fecundity estimates of this Sea Urchin from Pulau Pangkor, Peninsular Malaysia for the first time.