In others, the eggs may be stuck to the undersides of rocks.  Some starfish such as Astropecten polyacanthus also include powerful toxins such as tetrodotoxin among their chemical armoury, and the slime star can ooze out large quantities of repellent mucus. It has an adult weight of 20 g (0.7 oz), reaches sexual maturity in two years and lives for about ten years. Their diets include clams and oysters, arthropods, small fish and gastropod molluscs. Starfish are deuterostome animals, like the chordates. Individuals from deep water are usually paler. It normally lives on the outer surface of the starfish feeding on sloughed-off epidermal tissue. Most can regenerate damaged parts or lost arms and they can shed arms as a means of defense. Habitats range from tropical coral reefs, rocky shores, tidal pools, mud, and sand to kelp forests, seagrass meadows and the deep-sea floor down to at least 6,000 m (20,000 ft). The others may consume coral polyps, sponges or even planktons. Only the ossicles and spines of the animal are likely to be preserved, making remains hard to locate. ... ADW doesn't cover all species in the world, nor does it include all the latest scientific information â¦ Starfish Can Lose An Arm. Nevertheless, it is still sold throughout its range and beyond. They have complex life cycles and can reproduce both sexually and asexually. 5.- Valvatida. Starfish or sea stars are star-shaped echinoderms belonging to the class Asteroidea. Theâ¦ , The ciliate protozoan Orchitophrya stellarum is sometimes a parasite of the common starfish.  When such a larva senses that food is plentiful, it takes the path of asexual reproduction rather than normal development. In saltwater on bottom. In some species, mature females produce chemicals to attract sperm in the sea water. , Starfish do not appear to have any mechanisms for osmoregulation, and keep their body fluids at the same salt concentration as the surrounding water. The starfish does not have the capacity to plan its actions. Subphylum: Asterozoa. The roughly 1,600 living species of sea stars occur in all oceans; the northern Pacific has the Archaster, Brisingida with part of Velatida, e.g. Even a gap of just 1 mm (0.04 in) is sufficient for the starfish to insert a fold of its stomach, secrete enzymes and start digesting the mollusc body.  It is derived from the Greek aster, á¼ÏÏÎ®Ï (a star) and the Greek eidos, Îµá¼¶Î´Î¿Ï (form, likeness, appearance).  Many starfish species also became extinct in these events, but afterwards the surviving few species diversified rapidly within about sixty million years during the Early Jurassic and the beginning of the Middle Jurassic. Dec 24, 2019 - Explore Teresa gibbs's board "Starfish species" on Pinterest. Which of these processes occurs depends on the genus. Taxonomy. , With its multiple arms, the starfish provides a popular metaphor for computer networks, companies and software tools. â Calliasterellidae , The common starfish is native to the northeastern Atlantic Ocean and its range extends from Norway and Sweden, through the North Sea, round the coasts of Britain, France, Spain and Portugal and southwards along the coasts of Africa to Senegal. Physical Description Fertilization is generally external but in a few species, internal fertilization takes place. When the contents are sufficiently liquid, it brings its stomach back to its rightful position with the food inside.  The class Asteroidea belongs to the phylum Echinodermata. During the last 6,000 years, divergence in the larval development of Cryptasterina hystera and Cryptasterina pentagona has taken place, the former adopting internal fertilization and brooding and the latter remaining a broadcast spawner.  The Starfish and the Spider is a 2006 business management book by Ori Brafman and Rod Beckstrom; its title alludes to the ability of the starfish to regenerate itself because of its decentralized nervous system, and the book suggests ways that a decentralized organisation may flourish. Sometimes at the full moon time, when the moon is really dazzling and hitting on the ocean, a starfish jumps out of the water and falls down. These are honeycombed structures composed of calcite microcrystals arranged in a lattice. , Starfish sometimes have negative effects on ecosystems. This order contains about 200 species in five families.