Unformatted text preview: n-vertebrate clades Chordates Cephalochordates
• lancelets (or amphioxus); small filter-feeding marine animals
• chordate features present in adults
• segmented body muscles Cephalochordates
• lancelets (or amphioxus); small filter-feeding marine animals Non-vertebrate chordates Chordates Urochordates (Tunicates)
• sea squirts (ascidians) and relatives
• sea squirts are bag-like, with
enlarged perforated pharynx for
filter-feeding Why a chordate? Because urochordate larvae show all the chordate characters 1.
4. notochord dorsal hollow nerve postanal tail pharyngeal slits Sea squirt larva In another group of urochordates
(larvaceans) the adults are larvalike and they retain the chordate
features Colony of the light
bulb tunicate (Clavelina huntsmani). Colonial sea squirt (Botryllus schlosseri) Urochordates (Tunicates)
• Tunic composed mostly of cellulose hSp://www.uib.no/news/nyheter/2013/03/an
car 1. ...
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This document was uploaded on 06/25/2013.
- Spring '08