Unformatted text preview: adults with body walls composed of cellulose-like tunicin, and incurrent and excurrent siphons serving an enlarged filtering pharynx. They may be found living alone or in colonies. What chordate features are shared by the larvae and adults? What function does the pharynx serve? Sketch a larva and an adult in the space below; indicate the chordate characters present on your diagrams. Subphylum Cephalochordata (lancelets) Marine fish-like chordates showing an anterior oral hood overlying oral tentacles or cirri, chevron shaped (V-shaped) myotomes (muscle segments), but lacking any vertebral or cranial skeleton. Amphioxis is an example of a Cephalochordate; it is discussed below. Amphioxis is a primitive chordate that shows the four diagnostic features well, and also shows other structures that appear to be the forerunners of some typical vertebrate structures. Unlike other chordates, the notochord in Cephalochordates extends into the anterior most portion of the animal....
View Full Document
- Fall '11
- Biology, numerous short spines, armless echinoderms