Light-spotted Sea Cucumber

Overview

The Light-spotted Sea Cucumber (Holothuria hilla) is a nocturnal, cylindrical echinoderm widely distributed across the tropical Indo-Pacific and Red Sea. It is commonly found in shallow reef environments, where it plays an active role in maintaining substrate health by sifting through sand and detritus.

Distribution & habitat

This species inhabits a variety of tropical marine environments, including lagoons, seagrass meadows, and coral rubble areas. While typically observed in shallow waters between 1 and 30 meters, it has occasionally been recorded at depths exceeding 200 meters. During the day, individuals often seek shelter under coral rubble or within rock crevices, emerging at night to forage.

Appearance

Holothuria hilla features a soft, wrinkled, and elongated body that tapers toward the rear. Its coloration ranges from pinkish-tan or mustard yellow in juveniles to dark brown in adults. The dorsal surface is distinctively covered in creamy-white to yellowish, thorn-like papillae that give the animal a bristled appearance. The underside is equipped with rows of longer, yellowish tube feet, and the mouth is surrounded by a ring of twenty shaggy, peltate tentacles used for feeding.

Biology & behavior

Primarily nocturnal, this sea cucumber is a detritivore that feeds on organic matter found in the substrate. It is generally solitary and exhibits relatively low mobility. While it possesses Cuvierian tubules—defensive structures found in many sea cucumbers—it is noted for rarely, if ever, expelling them. The species is capable of both sexual and asexual reproduction, with the latter occurring through fission, which may allow for localized population growth.