Holothuria edulis Breeding Guide

How the pinkfish sea cucumber Holothuria edulis reproduces by broadcast spawning with planktonic larvae and by transverse fission, and why it is not home-bred.

Overview

Holothuria edulis, the pinkfish sea cucumber, is an Indo-Pacific holothurian reaching about 30 cm in length, usually dark reddish-black above and pinkish-mauve below. It is a detritivore that ingests sand and accumulated debris from the seabed with its feeding tentacles, occurring on sandy and muddy substrates, coral rubble and seagrass meadows down to about 20 m.

Reproductive Mode

The species has separate sexes and reproduces both sexually and asexually. Sexually it is a broadcast spawner, liberating gametes into the water column where fertilisation occurs; it can spawn at any time of year.

Asexual Reproduction

Holothuria edulis can also reproduce asexually by transverse fission, breaking into two parts, each of which then regrows the missing organs. This contributes to local population increase independently of larval recruitment.

Sexual Reproduction

Following external fertilisation the larvae are planktonic. As in sea cucumbers generally, development passes through a ciliated auricularia and then a barrel-shaped doliolaria before the juvenile form is reached, requiring an extended planktonic feeding period.

Common Challenges

The planktonic auricularia stage cannot be sustained in a display aquarium, so sexual propagation is not achieved at home. The toxin this species may release when stressed, although it does so only rarely, is an additional risk when handling or if the animal dies in the tank.