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Unformatted text preview: cles
derived from mesoderm, and covered in epidermis. The skeletal plates
(ossicles) are connected by a form of collagen which can be stiff or
flexible ! neuronal control of body tone without muscle action.
(secondarily derived) Sea lily mouth-> stomach 1-> stomach 2-> anus Mouth on oral
(under) side regions with tube
feet = ambulacra
has 2 stomachs: fluffy stomach and cardiac stomach two stomachs in
asteroids water vascular system
some has calcium
ring that attaches to ^synapomorphy
the bottom. the middle part then pulled up and become a suckers Hard calcium
ossicles in the
skin in every arm: 2 line of
tube feet, reproductive
structure (gonads), and
over the whole
thing. use the tube feet to eat Sea stars (Asteroidea) common, largely predatory (hold the bivalve close)
Fight: combined tube foot forces versus bivalve adductor muscles
and the role of the fluffy (cardiac) stomach catch collagen work like a ratchet
system is used
-respiration as soon as the
bivalve opens a bit
the fluffy stomach
comes out of the
mouth and sticks
itself out in the gap
sea stars usually
wins Class Echinoidea: sea ur...
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This document was uploaded on 04/13/2013.
- Fall '08