Description
Tissue: Organisms in phyla ctenophora are considered diploblastic, since they have an epidermis and gastrodermis. However, since ctenophorans have true muscle cells within their mesoglea, which is in between the epidermis and gastrodermis, scientists believe that ctenophrans could possibly be triploblastic.
Body Form: Most ctenophoras have comb rows, eight meridional bands of cilia, that sit between the oral and aboral poles. Such as the Pleurobranchia, which tends to reside in cold waters. Comb rows help in movement and are coordinated through a statocyst at the aboral pore. The Pleurobranchia has its aboral pole that faces downwards, when the pole tilts statocysts detect it, which causes the comb rows to adjust the organisms orientation. Ctenophorans have tentacles, that usually arise from the pouches near the aboral pole. These tentacles have contractile fibers that causes the tentacles to retract. Tentacles also have colloblasts, adhesive cells, which help in capturing prey.
Body Form: Most ctenophoras have comb rows, eight meridional bands of cilia, that sit between the oral and aboral poles. Such as the Pleurobranchia, which tends to reside in cold waters. Comb rows help in movement and are coordinated through a statocyst at the aboral pore. The Pleurobranchia has its aboral pole that faces downwards, when the pole tilts statocysts detect it, which causes the comb rows to adjust the organisms orientation. Ctenophorans have tentacles, that usually arise from the pouches near the aboral pole. These tentacles have contractile fibers that causes the tentacles to retract. Tentacles also have colloblasts, adhesive cells, which help in capturing prey.
Maintenance Functions: Ingestion begins when ctenophorans use their tentacles to wipe their prey across their mouth. The mouth then leads to the branched gastrovascular system. Usually the canals are blind. But, there are also two small anal canals that lead to the outside, meaning they have an anal opening. Through the anal canals waste is removed from the organism.
Reproduction: Ctenophorans are monoecious. The gastrodermis has two band-like gonads. One of which is an ovary, the other is a testis. Fertilization is external since gametes are released through the mouth, which results in a slightly flattened larva to develop.
Reproduction: Ctenophorans are monoecious. The gastrodermis has two band-like gonads. One of which is an ovary, the other is a testis. Fertilization is external since gametes are released through the mouth, which results in a slightly flattened larva to develop.