BI256 Lecture Notes - Lecture 20: Circulatory System, Clitellum, Oligochaeta
Document Summary
Nephrostome is found in adjacent body cavity. Anything you don"t want will drain out of nephridiopore. Leeches last hairs and suckers for locomotion. Only leeches are monophyletic while polychaeta and oligochaete are paraphyletic. Earth worms ad leech both have clitellum a band of cells around worms body to protect eggs which is only present in reproductive season in leeches. Most diverse group (paraphyletic), sedentary and errant types, paranoids with many setae. Paraphyletic, clitellum, no parapods, few setae, good for burrowing. Monophyletic, no setae, clitellum seaosnal, inchworm locomotion. When you squish an earthworm it bleeds red and it has respiratory pigments. These pigments are dissolved in blood not present in blood cells. Respiraroy pigment is not in blood cells. Dont need a gut if you are an endoparasite. Body cavities and germ layers *think in terms of complexity. Centapeeds with just one pair of legs per segment.
