Growth pattern of the tropical sea cucumber, Holothuria scabra, under captivity

Abstract

The growth of the juvenile sea cucumber, Holothuria scabra, was studied under captivity to elucidate the growth variation pattern and determine the best-fit growth model to estimate age- and size-specific growth rates. Individual growth was extremely variable, with some individuals below the mean initial weight and some expanding their original body length (L) and weight (W) by up to 6.4 and 156 times, respectively; during 84 days of culture starting at 127 days of age. Some of the smallest individuals showed a higher condition factor than larger individuals in the presence of ample food, indicating that lack of food may not be the only impediment to growth. Among the three growth models compared (von Bertalanffy, Gompertz and logistic), the Gompertz model was considered optimal to express H. scabra growth; both in L and W. The age- and size-specific daily growth rate for L and W up to 365 days of age, as estimated by the Gompertz model, had a range of two and nine orders of magnitude in L (0.035 – 0.96 mm/day) and W (3.4 × 10^-7 – 3.5 g/day), respectively. Use of the Gompertz model over the linear model, which tends to overestimate growth rates, is encouraged to estimate the growth of H. scabra more accurately.