BIOL 202 Chapter Notes - Chapter 9: External Fertilization, Hydrostatic Skeleton, Statocyst
18 Jun 2015
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Diploblastic (triploblastic?) tissues: because their mesoglea is highly cellular and contains true muscle cells which makes some zoologist think the middle layer should be considered a true tissue layer. Eight meridonal bands of cilia (comb rows) Aboral organ (opposite end of mouth: main component is a statocyst that is a balance sensory to sense its orientation. Capture prey via two long branched tentacles that possess contractile fibers that retract the tentacles, and adhesive cells, called colloblasts. Ingestion occurs as tentacles wipe prey across mouth which leads to a branched gastrovascular canal system. Has anal opening (unlike cniderians) for undigested waste to exit (also some exits through mouth. External fertilization, gametes shed through mouth, slightly flattened larvae develops.
