Asteroidea (2025)
: Most sea stars exhibit a distinctive starlike shape with five arms arranged around a central disc. However, some species can have up to 50 arms .
: Like all echinoderms, asteroids possess a unique network of internal channels used for locomotion, feeding, and basic circulatory functions. asteroidea
, commonly known as sea stars or starfish, are a highly diverse class of marine invertebrates within the phylum Echinodermata . With approximately 1,900 accepted extant species worldwide, they are found across all of the world's oceans, from the shallow intertidal zone to the deep sea (~6,000 m). Key Biological Features : Most sea stars exhibit a distinctive starlike