Growth and Size of the Tropical Sea Cucumber Holothuria (Halodeima) atra Jager at Enewetak Atoll, Marshall Islands

Abstract

In September 1975, 5031 sea cucumbers (Holothuria atra Jager) were tagged with tetracycline and returned to a gutter on the seaward reef bench of Ananij Island, Enewetak Atoll, Marshall Islands. A sample of 184 individuals was collected in September 1976. Animals were dissected and plates of the calcareous ring were examined with ultraviolet radiation for tetracycline lines. Based on 18 tagged individuals, the Brody-Bertalanffy growth constants are: K = 0.11 and P = 0.89 cm (for interradial plates). Length (L, cm) and weight (W, g) of individuals are related to plate size: L = 36.35P and W = 1950P3, giving maximum size as 32 cm and 1352 g. Length frequency distributions for the population did not change from 1975 to 1976. A preliminary estimate of annual loss is 50 to 70 percent of the total population based on the growth parameters and population size structure. Holothuria atra shows asexual reproduction by transverse fission, which appears to be the major source of recruitment at Ananij rather than from the plankton.