BIOL 2030 Lecture Notes - Lecture 14: Subphylum, Madreporite, Exhalation
Document Summary
Subphylum: plematozoa: class crinoidea (ex. sea lilies and feather stars) Develop interesting mechanisms: cuvierian tubules come out of their anus; stinging threads and can attach the threads and leave them behind so the prey can"t get away. Have good regenerative abilities: sea cucumbers eviscerate their gut which comes out of their mouth or anus and leaves their entire gi tract for the predator and regenerates their gut. Echinoderm features that are found in no other phylum: secondary radial symmetry (pentamorous symmetry) Cut through centre 5 ways to obtain similar parts. Ve cuts through the animals longitudinal axis and the pieces are equal: a water-vascular system. Based on the cross-section you only see the perivisceral coelom and the tube feet of water vascular systems) I. e. tiny pincer-like structures on the outer surface of many members of this phylum: dermal branchiae (papulae) Ie. projections of the coelomic cavity with respiratory (and excretory) functions: an endoskeleton of plates or ossicles (sometimes spiny)
