Bio 193 Ch. 33 Echinodermata

Echinodermata

phylum of marine animals that includes sea stars, sea urchins, sand dollars, and sea cucumbers. They are characterized by radial symmetry, a water vascular system, and a spiny or leathery exoskeleton.

echinodermata have ____ symmetry

radial

echinodermata lack _____

cephalization

the spiny calcite endoskeleton provides

structural support

water vascular system

helps echinoderms move, feed, and breathe

water vascular system powers

tube feet

water vascular system used for

gas exhange and feeding

sea stars are carnivores/herbivores

carnivores, feed by extending their stomachs to digest prey outside their bodies.

brittle stars move by

lashing long arms

urchins graze on algae using

their specialized mouthparts called Aristotle's lantern.

sea cucumbers feed how?

filter feeding

echinoderm fertilization is

mostly external, occurring in the water.

larval stage has what symmetry

bilateral symmetry

what evidence that Echinodermata and chordata are closely related

DNA, Deuterostomia, bilateral symmetry as larva

as climate changes what happens to oceans

warm and acidify

acid reacts with and tie up

carbonate ions

to make calcium carbonate need free ____

carbonate ions

organisms must expend more energy to form calcium carbonate, so

Less energy remains for growth, reproduction, and survival

acidification interferes with construction of

coral reefs, molluscs cant form shells, echinoderms for fewer skeletal spines