ZOL 353 Lecture Notes - Lecture 34: Water Vascular System, Deuterostome, Tube Feet
Document Summary
Echinodermata: sea stars, brittle stars, crinoids, sea cucumbers, sea urchins: echinodermata, deuterostomia, pentaradial (5-point) symmetry typical of adults. In some, male climbs on top of female in pseudocopulation and they both release gametes: protected by spines, toxins, slime, etc. Larva vs. juvenile of the sea star luidia sarsii: larva of this species becomes unusually large, up to 3. 5 cm long. Larva can live on without juvenile for months: sea urchins: class echinoidea, phylum echinodermata, c. 950 species, no appendages, test or skeleton made up of tightly interlocking plates. Can be round to flat: movable spines in life. In metamorphosis, larval notochord lost and tail resor(cid:271)ed, (cid:272)e(cid:373)e(cid:374)ts i(cid:374)to su(cid:271)strate at (cid:862)head(cid:863) Branchiostoma (amphioxus): similar to hypothetical vertebrate ancestor, several gonads instead of the pair typical in vertebrates, spend their lives half-buried and filter-feeding in sand (a) the sea squirt ciona. (c) a tadpole larva (ca.
