cushion star

A cushion star is a type of sea star belonging to the genus Goniaster and related genera. These marine invertebrates, part of the phylum Echinodermata, are characterized by their thickened, more or less globose, pentamerous (five-sided) shape.1

Sea stars, despite their name, are not fish. They typically have five arms surrounding a central disk and inhabit all oceans. Their arms, which can regenerate if lost, are covered in spines and feature tube feet used for locomotion and clinging to surfaces. Sea stars feed by either everting their stomach to digest prey externally or by swallowing prey whole.2

Reproduction in sea stars is usually sexual, with males and females releasing eggs and sperm into the water for external fertilization. However, some species can reproduce asexually through fragmentation.32