Sea cucumbers in Pulau Bidong waters : the study of species diversity and abundance

Abstract

A total of nine sea cucumber species were recorded along the period of study. Three of the species were encountered within transects, which were Holothuria (Halodeima) atra, Holothuria (Halodeima) edulis, and Stichopus chloronotus. Other collected specimens were identified as Actinopyga lecanora, Actinopyga miliaris, Bohadschia vitiensis, Cercodemas anceps, and Stichopus vastus. One specimen was identified only to the genus Stichopus, due to the insufficient scientific references accessed to this species. All identified species were confirmed to be tropical Indo-Pacific sea cucumber species, and had been recorded in previous studies in Pulau Bidong, Pulau Redang, Pulau Perhentian, and Spermonde Archipelago, Indonesia. A total of 86 individuals were encountered in transects, with T3 in sandy area has the highest abundance (45 individuals), followed by T2 in coral reef area (39 individuals), and T l in intertidal area nearest to the beach (two individuals). T3 has the highest diversity (four species) with the other two transects only recorded two species. T3 recorded the highest average (n=6) diversity index (0.93 7±0.336) followed by T 1 (0.167±0.236) and T2 (0.130±0.290). T3 has the highest average (n=6) evenness index (1.213±0.929), followed by T l (0.333±0.471), and T2 (0.130±0.290). Univariate ANOVA showed that high significant differences (P<0.001) in individual abundance, total species, diversity and evenness factors between transects. The highest sea cucumbers found in transects was during 3rd sampling session (12-2 p.m.) with 44 individuals, while the lowest was during 2°d sampling session (10 a.m. -12p.m.) with two individuals.