Sea urchins are spiny, globular echinoderms in the class Echinoidea. About 950 species of sea urchin are distributed on the seabeds of every ocean and inhabit every depth zone from the intertidal seashore down to 5,000 meters. The spherical, hard shells (tests) of sea urchins are round and covered in spines. Most urchin spines range in length from 3 to 10 cm, with outliers such as the black sea urchin possessing spines as long as 30 cm (12 in). Sea urchins move slowly, crawling with tube feet, and also propel themselves with their spines. Although algae are the primary diet, sea urchins also eat slow-moving (sessile) animals. Predators that eat sea urchins include a wide variety of fish, starfish, crabs, marine mammals, and humans.
Neomphaloidea is a superfamily of deep-sea snails or limpets, marine gastropod mollusks. Neomphaloidea is the only superfamily in the order Neomphalida.
Eulimidae is a family of very small parasitic sea snails, marine gastropod mollusks in the superfamily Vanikoroidea.
Provannidae is a family of deep water sea snails, marine gastropod mollusks in the superfmaily Abyssochrysoidea.
The Vermetoidea, the worm snails or worm shells, are a taxonomic superfamily of small to medium-sized sea snails, marine gastropod molluscs in the order Littorinimorpha.
Murchisonellidae is a taxonomic family of sea snails, marine opisthobranch gastropod mollusks in the superfamily Murchisonelloidea.
Osteopelta is a genus of sea snails, marine gastropod mollusks in the family Osteopeltidae.
Bruceiella is a genus of sea snails, marine gastropod mollusks in the family Skeneidae.
Pleioptygma is a genus of large sea snails, marine gastropod mollusks in the superfamily Muricoidea.
Asterophila is a genus of medium-sized sea snails, marine gastropod mollusks in the family Eulimidae.
Asterolamia perknasteri is a species of sea snail, a marine gastropod mollusk in the family Eulimidae. The species is one of three known species within the genus Asterophila; the other congeneric species are Asterophila japonica and Asterophila rathbunasteri.
Asterophila rathbunasteri is a species of sea snail, a marine gastropod mollusk in the family Eulimidae. The species is one of three known species within the genus Asterophila; the other congeneric species are Asterophila japonica and Asterophila perknasteri.
Clypeastericola is a genus of medium-sized sea snails, marine gastropod mollusks in the family Eulimidae.
Clypeastericola clypeastericola is a species of sea snail, a marine gastropod mollusk in the family Eulimidae. This species is one of two known species to exist within the genus, Clypeastericola, the other species is known as Clypeastericola natalensis.
Clypeastericola natalensis is a species of sea snail, a marine gastropod mollusk in the family Eulimidae. The species is one of two known species to exist within the genus, Clypeastericola, the other one is known as Clypeastericola clypeastericola.
Eulima encopicola is a species of sea snail, a marine gastropod mollusk in the family Eulimidae. The species is one of a number within the genus Eulima.
Hypermastus is a genus of sea snails, marine gastropod mollusks in the family Eulimidae.
Hypermastus orstomi is a species of sea snail, a marine gastropod mollusk in the family Eulimidae.
Nanobalcis is a genus of minute sea snails, marine gastropod mollusks in the family Eulimidae.
Mespilia globulus, the globular sea urchin, sphere sea urchin, or tuxedo urchin, is a sea urchin occurring in tropical shallow reef habitats. The specific name refers to a small ball or spherule, describing its overall shape/morphology. It is the only species in the genus Mespilia.
