BIOL 2030 Lecture Notes - Sea Anemone, Rhopalium, Siphonophorae

• School: York University
• Department: Biology
• Course: BIOL 2030
• Professor: Scott Kelly

Document Summary

Cnidaria phylum of simple, aquatic, mostly marine, invertebrate animals containing corals, sea fans, and sea anemones (class anthozoa), the hydroids and milleporine corals (hydrozoa), the jelly-fishes (scyphozoa) and the box-jellies (cubozoa). Individuals are generally radially symmetrical, with only one opening (mouth) to the gut and a simple two-layered body with a primitive nerve net between the two layers. Cnidaria have hydroid (polyp) and/or medusa forms, and bear stinging cells (cnidoblasts) on the tentacles fringing the mouth. With the phylum ctenophora, the cnidaria form the largest grouping known as the coelenterates. Cnidocil minute process projecting from a cnidoblast (stining cell), whose stimulation causes. Colloblast stinging cell of sea anemone, jellyfish, and other coelenterates, containing a coiled discharege of a nematocyst thread which is dischared on contact with prey. Comb plates a locomotor organ consisting of a row of strong cilia whose bases are fused.