User:Ballaman365/Anal pore

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ctenophores are marine animals superficially resembling jellyfish but having biradial symmetry and swimming by means of eight bands of transverse ciliated plates. All ctenophores possess a pair of small anal pores located adjacent to the apical sensory organ thought to control osmotic pressure. These animals are also with animal pore. They are not quite as ‘simple’ as one might first imagine. Ctenophores which have sometimes been interpreted as homologous with the anus of bilaterian animals (worms, humans, snails, fish, etc.). Furthermore, they possess a third tissue layer between the endoderm and ectoderm, another characteristic reminiscent of the Bilateria. We unequivocally show that ctenophores possess a functional through-gut from which digestion waste products and material distributed via the endodermal canals are expelled to the exterior environment through terminal anal pores that are anatomically physiologically specialized to contro outflow from the branched endodermal canal system. Ctenophores have no true anus; the central canal opens toward the aboral end by two small pores, through which a small amount of egestion can take place. On the right are pictures of ctenophores with anal pores.