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Unformatted text preview: Sea stars (Asteroidea) • central disk, with large arms • common, many are predatory Crown-of-thorns starfish effects on coral reefs. Brittle stars (Ophiuroidea) • long slender arms that provide locomotion • abundant but secretive (light-avoiding) BIS2C W2011 Lecture 33 (7 March 2011) 2 Sea urchins (Echinoidea) • no arms; usually with long spines • ossicles fit together into a test • omnivores; important as grazers of algae Examples of “keystone species”: 1. Diadema sea urchins in the Caribbean 2. Kelp-consuming sea urchins off the California coast Sea cucumbers (Holothuroidea) • soft-bodied and slug-like • elongated oral/aboral axis, secondary bilateral symmetry • can expel parts of their gut as anti-predator defense (see: http://www.youtube.com/watch?v=lKWSLg5PDiU ) Web sites http://tolweb.org/tree?group=Echinodermata&contgroup=Deuterostomia http://research.calacademy.org/research/izg/echinoderm/ http://en.wikipedia.org/wiki/Echinoderms...
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- Spring '11
- Deuterostome, California coast Sea, sea lilies, BIS2C W2011 Echinodermata