BIOL10005 Lecture Notes - Lecture 15: Water Vascular System, Madreporite, Triploblasty
31 Oct 2018
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Pheromones: compound eyes (evolution in the cambrian) Echinoderms to chordates: echnioderms (starfish, sea ur(cid:272)hi(cid:374), sea (cid:272)u(cid:272)u(cid:373)(cid:271)ers, ) Pentaradial as adults -> larger surface area to detect prey/predators. Water vascular system in coelom (madreporite is the opening of the vascular system) -> facilitates movement. Tube foot present connected to water vascular system. Modified spines with claws and capable of movement. Remove encrusting organisms: ejection of intestines (sea cucumber) Stiff rod of mesoderm found next to the nerve chord (located dorsally) in all embryos -> functions as endoskeleton. Vertebrae (spine) grows around the notochord as embryo develops. Vertebrae surrounds & protects the nerve chord e. g. ) (495-350 mya) was a diverse group of fish. Only 2 presently existing groups: lampreys & hagfish -> blood-sucking parasites e. g. ) Some give birth to live young e. g. ) Earliest jawed fish: placoderm late silurian (420 mya) 350 mya, bony fish living in shallow lagoons developed these bones for paddling. Early amphibians had both gills and lungs.
