PHYLUM CTENOPHORA

The ctenophores or comb-jellies are a group of biradially symmetrical animals that show many similarities to the cnidarians. (A biradially symmetrical animal is "flattened" so that one could obtain equal halves by dividing the animal along one of two planes. A flattened apple is a good analogy.) Observe this preserved specimen. Note the rounded body form and the eight "comb rows" which give this group its name. These are actually rows of fused cilia. The beating of these combs moves the animal through the water. Each animal also has two long ciliated tentacles (click the 'more images' button to see these on the image of a living comb-jelly). The tentacles are equipped with adhesive cells which are used to capture prey (ctenophores are all carnivorous).