Echinodermata notes - tube • Circulatory system = central ring and five radial vessels but no heart • sexually mature after approximately two

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
Echinodermata! the first definitive members of the phylum = Cambrian period. second-largest grouping of deuterostomes, after the chordates; largest phylum that has no freshwater or terrestrial representatives. main subdivisions of Echinoderms : motile Eleutherozoa ,(starfish), Ophiuroidea (brittle stars), Echinoidea (sea urchins and sand dollars) and Holothuroidea (sea cucumbers) Echinoderms possess a water vascular system, a network of fluid-filled canals that function in gas exchange = no gill slits very simple, often simply leading directly from mouth to anus (but has a digestive
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: tube) • Circulatory system = central ring and five radial vessels, but no heart • sexually mature after approximately two to three years, eggs and sperm cells are released into open water, where fertilization takes place (except for some species of starfish) • Some echinoderms (starfish) can regenerate. From one missing arm, it can generate a completely new starfish. • Feeding - filter-feeders, STARFISH – invert stomach…engulf food, digest it once, then send it to the second stomach to digest it again…ok...
View Full Document

This note was uploaded on 10/18/2011 for the course BIO 1103 taught by Professor Brickman during the Spring '08 term at University of Georgia Athens.

Ask a homework question - tutors are online