Holothuria hilla (Lesson, 1830)

Abstract

Holothuria hilla is classified by IUCN Red List, it is belong to soft-bodied holothuroid, a nocturnal species and is found on inner reef flats, usually in seagrass beds or coral rubble, to depths of 3-20 m. During the day H. hilla can be found under coral rubble, emerging at night to feed. Detritivorous deposit feeder.. During the day it was found under coral rubble, emerging at night to feed. Members of the class Holothuroidea are gonochoric and have only one gonad. H. hilla has asexual and sexual reproduction. This species is usually rare, it is likely that the species has proliferated on rarely site by asexual reproduction from a few specimens. Fission occurs year round, it appears to be more prevalent in cooler months. The sex of the specimen could not be determined in the indeterminate specimens. Spawning and fertilization are both external and some exhibit brooding. Embryos develop into planktotrophic larvae (auricularia) then into doliolaria (barrel-shaped stage) which later metamorphose into juvenile sea cucumbers. The biggest size observed 1.5 meter in Persian Gulf (Kish Island).