Phylum Ctenophora
Ctenophora is another phyla that contains the comb jellies. Comb jellies look a lot like jellyfish, and for this reason many people think of them as jellyfish. However, comb jellies are in a whole different phylum than jellyfish, and they make up the whole phylum. Jellyfish are actually in Cnidaria, which is the same phylum that corals, sea anemones, and hydras are in. There are a little over 100 species of comb jellies, which is not a lot, but because they are so distinctive from their relatives, the Cnidarians, they develop a new phylum. However, like the cnidarians, comb jellies have radial symmetry, which classifies them in group Radiata. Ctenophores, like many simple invertebrates, live in the ocean. Unlike sponges. Ctenophores actually have tissues which make up organs. Instead of a brain, however, Ctenophores have a nerve net. Although the Ctenophore’s body looks like that of a jellyfish, comb jellies can be distinguished by their combs, which besides being their distinctive feature, they also use them for swimming. While many comb jellies are small, just a couple of inches wide, large comb jellies can grow up to be nearly 5 feet long. A comb jelly’s body structure is similar to that of a cnidarian. Their body is made of a mass of jelly-like substance called mesoglea. Comb jellies feed by moving through the water, picking up its food, zooplankton. Zooplankton are very small animals that eat phytoplankton, which are very small plants. Food that comb jellies eat get liquefied by enzymes in the throat, and then pushed down through the throat and into its jelly-like body. Most comb jellies reproduce sexually. These comb jellies are hermaphrodites, but unlike sponges, comb jellies actually do have sex organs. Although this is the way most comb jellies reproduce, a few reproduce asexually, by splitting of a small piece of their bodies. The small piece eventually grow into an adult comb jelly and the process starts all over again.
Symmetry: Radial
Species Number: 100+
Classification:
Kingdom Animalia
Eumetazoa
Radiata
Phylum Ctenophora
Class Nuda (beroid comb jellies with no tentacles)
Class Tentaculata (common comb jellies with tentacles)
Heading Picture: Venus girdle (Cestum veneris)
Class Tentaculata (common tentacle comb jellies)
Order Cestida (flat, ribbon shaped comb jellies)
Family Cestidae
Genus Cestum
Species Cestum veneris (venus girdle)
Symmetry: Radial
Species Number: 100+
Classification:
Kingdom Animalia
Eumetazoa
Radiata
Phylum Ctenophora
Class Nuda (beroid comb jellies with no tentacles)
Class Tentaculata (common comb jellies with tentacles)
Heading Picture: Venus girdle (Cestum veneris)
Class Tentaculata (common tentacle comb jellies)
Order Cestida (flat, ribbon shaped comb jellies)
Family Cestidae
Genus Cestum
Species Cestum veneris (venus girdle)