Slate Pencil Urchin

Description:

a "sluggish echinoid" that leads a nocturnal, benthic existence. During daylight hours, the slate pencil urchin uses its large primary spines to anchor itself under or atop rocks or to lodge itself in crevices. Individuals rarely stray far from their locality. At night, they will feed primarily on corals and sponges, among other things.

Habitat:

ocean bottom

Notes:

Reproduction in E. tribuloides seems to be sensitive to both seasonal cycles and the lunar cycle. In the Florida Keys, E. tribuloides was found to obtain peak gravidity in the late summer and early fall.Populations in Panama, however, were found to be gravid in the spring, summer and fall, with peak gravidity occurring around the full moon.