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Spiny Skins

Group 4: Echinodermata

Spiny Skins

Group 4 - Echinodermata: With about 7,000 known living species Echinodermata is the largest phylum of marine animals. They can be found throughout the oceans, in every temperature and depth range.

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5 Fun Facts - Echinodermata

Fun facts Echinodermata

There are five main classes of echinoderms: Asteroidea (Starfish or sea stars), Ophiuroidea (brittle stars and basket stars), Echinoidea (sea urchins), Holothuroidea (Sea cucumbers) and Crinoidea (crinoids and feather stars).

Spiny skin: The phylum name Echinodermata means "spiny skin", which is a feature common to many echinoderms.

Pentamerous: Adult echinoderms are pentamerous, meaning their body has five-point radial symmetry. This symmetry is obvious with starfish, brittle stars and sand dollarss. In others, like sea urchins and sea cucumbers, it is more difficult to recognize.

Water vascular system: All echinoderms have a water vascular system, which is a network of canals that starts at the main body cavity and connects to the animals many tube feet. Echinoderms move by contracting and releasing muscles that push water through the canals and into the feet, causing to extend and retract.

Regeneration: Many echinoderms can regenerate, able to regrow arms, organs or spines lost in self-defense or damaged by predators. In some species, a single severed arm can regrow into and entirely new organism.

Defense: Many species of echinoderms secrete toxins. They can either be present on the skin at all times or can be excreted through the tube feet when the organism us attacked or threathened.

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