Invertebrate

Invertebrates are animals that lack a vertebral column. This diverse group includes soft-bodied organisms such as anemones and jellyfish, as well as those protected by shells or exoskeletons, like molluscs and crustaceans. Adult sizes vary widely, from a few millimetres in some worms and small crustaceans to several metres; large sessile forms like sponges and gorgonian corals can exceed 3 metres (10 ft) in height or spread.

They inhabit a broad range of marine environments, from shallow intertidal zones to mesophotic reefs at depths over 100 m (330 ft). Many species contribute to the structural framework of coral reefs, forming the matrix of the ecosystem. Others burrow into sediments or live symbiotically with fish and other invertebrates. Feeding strategies are diverse, encompassing filter feeding, grazing on algae, and active predation.