BISC 121Lg Lecture Notes - Lecture 14: Ctenophora, Gastrovascular Cavity, Scyphozoa
Document Summary
Eumetazoa- simple muscles and nerves: cindaria- have a gastrovascular cavity. Have comb jellies, ciliary plates, adhesive colloblasts. Cnidaria- sessile polyp and mobile medusa: cylindrical polyps adhere to substrates using aboral end. Do(cid:374)"t (cid:373)o(cid:448)e: medusas are flattened, inverted polyps that are capable of drifting both passively and actively, carnivores. Hunt using tentacles: hydrozoa- portuguese man of wars, hydras, some corals. Alternate between polyp and medusa usually some exist as only one or the other. Hydra have photosynthetic symbionts: cubozoa and scyphozoa both have very short polyp stages if they even have one. Spend most of their time in the medusa stage. Medusa stage: coastal scyphozoa have short polyp stages. Wide ocean scyphozoa usually have no polyp stage: anthozoans occur only as polyps. Calcium carbonate (caco3) structure is what makes it hard. Ea(cid:272)h (cid:374)e(cid:449) ge(cid:374)eratio(cid:374) of the orga(cid:374)is(cid:373) (cid:271)uilds o(cid:374) the per(cid:448)ious ge(cid:374)eratio(cid:374)"s skeletal remains.
