Biology / Unit 10 Bio 2279 short lesson, about 20 seconds
Echinoderm Body Plan: Water Vascular System
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The idea
An echinoderm moves and feeds using a water vascular system, a network of fluid-filled canals powering tube feet, showing radial adult symmetry.
In practice
A sea star's tube feet, driven by water pressure, grip surfaces and pry open bivalve shells.
Where people slip
Adult echinoderm radial symmetry is a secondary trait — larvae are bilaterally symmetrical, matching their deuterostome ancestry.
Your place on the trail
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