Mespilia globulus Breeding Guide

How the tuxedo urchin Mespilia globulus reproduces as a gonochoric broadcast spawner, why its planktonic larvae are not raised in home tanks, and notes on brooding.

Overview

Mespilia globulus, the blue tuxedo urchin, is a small Indo-Pacific echinoid up to about 5 cm in diameter. Ten bare vertical zones of vibrant blue or green skin alternate with bands of brown, red or dark spines up to 2 cm long, giving the tuxedo pattern. It grazes on organic material settled or growing on hard surfaces and the sea floor across shallow reefs, coral rubble and seagrass beds.

Reproductive Mode

The species is gonochoric, with separate male and female individuals, and reproduces by broadcast spawning: clouds of sperm and eggs are released by the animals and fertilisation occurs in the water column. Spawning is reported from July to September in the Pacific and Indian Oceans.

Sexual Reproduction

After external fertilisation the embryos develop, like other urchins, into free-swimming planktonic echinopluteus larvae that feed for an extended period before settling and metamorphosing into juveniles. Brooding is also reported in this species, with eggs held on the peristome or within concavities of the test.

Common Challenges

The drifting planktonic larvae need controlled microalgal culture over weeks to months, so the tuxedo urchin is not bred in home reef aquaria. Released gametes and larvae do not survive normal tank filtration and predation.