BIO 2135 Lecture Notes - Lecture 2: Gastrovascular Cavity, Symmetry In Biology, Pedal Disc
15 Feb 2016
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Autapomorphies cnidocytes epitheliomusculature polyp body plan planula larva. Mouth surrounded by a series of cnidocytes-armed tentacles particles small enough to be absorbed through phagocytosis: tentacles capture food and pass it through the mouth into the. Plan coelenteron: incomplete gut waste is excreted through the mouth can live singularly or in colonies; colonies are linked by a common gastrovascular cavity. When living in colonies, often specialize for different functions: gastrozooids - feeding, gonozooids - reproduction, dactylozooids defense. Autapomorphies become symplesiomorphies at higher levels of organizations. Each subsequent group adds something that makes it unique. These classes all share the autapomorphies of the cnidaria, making these traits symplesiomorphies. There is no medusa stage in the life cycle; lives exclusively as a polyp: two kind of poly: tiny, colony- forming individuals (coral reefs), and large, solitary individuals (sea anemones) biradial symmetry siphonoglyphs. Muscular septa gonads in the gastrodermis non-opercular nematocysts *not on the exam.
