The ecology of Holothuriafuscogilva was assessed in three habitats in the Republic of Maldives: marine grass beds, island gaps and lagoon floor. In the lagoon floor habitat, H fuscogilva was the dominant sea cucumber with relative abundances ranging from 70 to 94.9% in the two atolls studied. In one island gap area the median density (biomass), movement and growth rate were 29 ha-I (21 kg ha-I), 2 m d-I and 0.29% d-1 , respectively. Based upon the weight distributions in the three habitats, H fuscogilva appears to recruit to shallow marine grass beds, then migrates to deeper waters such as island gaps. It then moves to the deep waters of the lagoon floor, as it approaches sexual maturity (1.5 kg TW), where it matures and reproduces. Growth slows as the animal matures and individuals with total weights of 5000 g or greater were estimated to be at least 12 yrs old. Based upon micro and macroscopic examination of extracted gonads, mature individuals from the lagoon floor were found primarily from August through May. Spawning of both male and females was observed between December and March or essentially the N. east monsoon season in the Maldives.