Growth, Age Structure and Population Parameters of Pink Sea Cucumber (Holothuria edulis) in Tioman Island, Pahang, Peninsular Malaysia

Abstract

The pink sea cucumber (Holothuria edulis) is one of the important tropical Holothurian, which occurs abundantly in the Indo-Pacific region including Tioman Island, Peninsular Malaysia. A field study was carried out for one year between March 2016 and February 2017, and the length-weight data of H. edulis was taken through monthly samplings, measured accordingly and analyzed using the FiSAT II (FAO-ICLARM) software. Mean total length and total weight of the population was calculated as 26.92 cm and 22.28 g, respectively. The Von Bertalanffy growth parameters such as asymptotic length (L∞) and coefficient of growth (K) and age were estimated to be 47.78 cm, 1.00 yr-1 and 3 yrs, respectively. The length-weight relationship of the population was established as W = 0.810L1.8 (R2 = 0.812). The growth of the H. edulis was negatively allometric (b<3) as revealed from the length-weight relationship. The estimated total mortality (Z), natural mortality (M) and fishing mortality (F) were 2.81 yr-1, 1.54 yr-1 and 1.27 yr-1 in that order. The result demonstrated that the fishery was underexploited as the present exploitation rate, E = 0.45, which was less than the optimum exploitation rate, Eopt = 0.5. This exploitation rate (E) also suggested that only 45% of the available stock biomass was being harvested yearly. The estimated recruitment pattern was bimodal, with peak recruitment of 19.66% occurred in July, 14.02% in June and 12.7% in September, respectively. This study represents the first successful investigation on the population structure and growth parameters of pink sea cucumber (H. edulis) in Malaysia, the findings of which will immensely be helpful not only for the understanding of population status of this species but also for their biodiversity conservation and aquaculture development to a greater extent. Key words: Sea cucumber, Holothuria edulis, population parameters, growth, mortality, Tioman