BIOL 2P92 Lecture Notes - Lecture 9: Strobilation, Tubularia, Jellyfish
6 Feb 2017
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Document Summary
Ancestral form was a stationary anthozoan form. Epetheliomuscular and nerve cells in hydra: direct connections between cells that can act as both epithelium and muscle cells, some are neurosensory, signals can go in both directions different from us. Methods of reproduction (strobilation type of fission within jellyfish) Rhopalia (eyes used as a sensory organ) Life cycle of aurelia, a marine scyphozoan medusa undergoes strobilation: sperm finds substrate, develops into a polypoid form (almost like a medusa) Divides into ephyra (little medusa), which develops into a mature meduzoid. Cubozoa have complex eyes, and are almost stiff looking. Has 4 long tentacles (distinguishing factor against others) In some species, they lose their polyp form and only exist in the medusa form: portuguese-man-of-war colony of hydrozoans in which a polyp like section becomes a gas bladder. When cnidarians are grouped into colonies, they are easily distinguishable. Stolons are used to describe the roots of animals such as hydras.
