Prey capture jellyfish

Cnidarians pose a particularly difficult challenge. The toxins produced by jellyfish and some hydrozoans are among the most powerful known, and have been relatively well characterized (Russell 1984). However, because the toxins are delivered through diverse kinds of nematocysts, experimental manipulations may be difficult. The role of toxins in prey capture has been inferred from the isolation of nematocyst-associated toxins, the behavior of exposed prey, and... 

The phylum Coelenterata is subdivided into the classes Hydrozoa, Cubozoa, Scyphozoa, and Anthozoa. The latter class is subdivided into Hexa- and Octocorallia. Many coelenterates produce toxic or other biologically active metabolites 235). For example toxins are used by jellyfish and sea anemones for defence or in order to capture prey. 

Of small size, 0.5-10 cm, chaetognaths have an elongated shape composed of three parts the head, trunk, and tail. The last two parts are equipped with three pairs of flippers, which make the animal look like a vaned torpedo and allow fast movement in open water these animals are almost all planktonic. Carnivorous and voracious, chaetognaths capture their prey with chitin-ous hooks, and feed mostly on copepods, pelagic crustaceans, jellyfish, sometimes small fish, and even other chaetognaths. 

There is a class of jellyfish regarded as aberrant to the extent that they live fixed to the bottom by a foot and the fact that they are upside down in that the umbrella is at the top, for the capture of prey. These small organisms, 5 cm on average, belong to the order Stauromedusae (which includes Lucernaria), the best known species of which is Haliclystus auricula,... 

Formerly associated with Cnidaria in the subkingdom of Coelenterata, the phylum Ctenophora differs from the Cnidaria in the absence of nematocysts. Morphologically similar to jellyfish and exclusively marine, Ctenophora are carnivorous animals that capture their prey with adhesive cells, the colloblasts. They move by means of a musculoskeletal system consisting of hairy plates, hence their old name of comb jellies. The presence or absence of tentacles separates Ctenophora into two classes the Ten-taculata, which are the most munerous and the Nuda, which are represented only by the order Beroida and the... 

---