Diet

• Ophiuroidea includes a wide variety of feeding strategies, including deposit feeding, suspension feeding, scavenging, predation, and omnivory.

• Many species collect organic particles and microorganisms from sediments, while others capture plankton or small invertebrates with their arms and tube feet.

• Basket stars use their highly branched arms to trap plankton and other suspended particles.

Range

• Found in marine environments throughout the world's oceans, from tropical waters to polar regions and from shallow intertidal habitats to the deep sea.

• Ophiuroidea is well represented in the tropical eastern Pacific, including the Mexican Pacific.

• Numerous species occur around Zihuatanejo

Habitat

• Most species are bottom-dwelling and occur on rocky reefs, coral, rubble, sand, mud, and other seafloor substrates.

• Many hide beneath rocks, within crevices, among coral, or partly buried in sediment, while others live openly on the seafloor.

• Some species live on other organisms, including corals, sea pens, sponges, sea urchins, and crinoids.

• The class occupies an exceptionally broad depth range, from the intertidal zone to abyssal depths exceeding 5,000 metres.

Description

• Brittle stars and basket stars with a distinct central disc and usually five long, slender, flexible arms.

• The arms are sharply separated from the central disc and contain articulated calcareous skeletal elements that function somewhat like vertebrae.

• Brittle stars use muscular arm movements for locomotion rather than relying primarily on their tube feet.

• The mouth is located on the underside of the central disc and is surrounded by five jaw-like plates; there is no anus, with waste leaving through the mouth.

• Arms are readily shed when the animal is attacked or disturbed and can subsequently regenerate, giving the group its common name “brittle stars”.

• Basket stars differ in having arms that branch repeatedly, sometimes producing an elaborate network used for capturing suspended food.