BIOL 2030 Lecture : Echinodermata.docx

• School: York University
• Department: Biology
• Course: BIOL 2030
• Professor: Scott Kelly

Document Summary

Echinoderamata phylum of marine coelomate animals that are bilaterally symmetrical as larvae but show five-rayed symmetry as adults and have a calcareous endoskeleton and a water vascular system; includes crinoidea, asteroidea, ophiuroidea, echinoidea, holothuroidea. Aboral away from, or opposite to, the mouth. Ambulacrum elongated area of the shell of echinoderm in which a row of tube-feet is arranged. Internal reservoir on ring canal of water vascular system in echinoderms. Asteroidea class of echinoderms, commonly called starfish or sea stars, having a star-shaped body with five radiating arms not sharply marked off from the central disc. Crinoidea sea lilies/feather stars: cup-shaped body with feathery arms, and areattached to the substratum by a stalk in the case of sea lilies. Echinoidea sea urchins: have a typically globular body with skeletal plates fitting together to form a rigid test. Eleutherozoa mobile animals with the mouth directed towards the substrate.