BIO153H5 Lecture Notes - Lecture 19: Notochord, Water Vascular System, Sea Urchin
Document Summary
There has been that xenoturbellida is a protostome and not a deuterostomes. One opening (not sure if mouth or anus) They are grouped with deuterostomes (in textbooks but books are old) Problematic: they have only one single opening. That opening is used for feeding but also to excrete. Bilaterally symmetrical as larvae but radially symmetrical as adults. Sea stars have bodies with 5 or more long arms radiating from a central region that contains the mouth, stomach and anus. Echinodermata: echinoidea (sea urchins and sand dollars) Sand dollars use their mucus-covered podia to collect food particles in sand. Echinoids have a unique, jawlike feeding structure in their mouths made up of 5. Sexual production predominates in echinoids (sexes are separate) A supportive but flexible rod that runs the length of the body. Bundle of nerve cells running next to the notochord. Allows us to separate chordates from non-chordates.
