Abdominal pores (latin: pori abdominales) are small paired openings lying usually inside or near the cloaca: sometimes behind, sometimes on the sides, connecting the body cavity with the external environment. The opening of the cloaca discharges between the pelvic fin bases. The cloaca has opening for the urogenital ducts, rectum, and abdominal pores, which connect the cloaca with the body cavity.

     They serve to regulate the pressure of intracavitary fluid (excess of it flows through the abdominal pores to the outside). In the shark Laemargus borealis they also serve for excretion of genital products.

     In the protopteryx, they lie at the bottom of the canal, lying lateral to the anus. Abdominal pores are found in fish (sharks, whole-headed, double-breasted, sturgeons, polychaetes, bony gannoids and salmonids) and reptiles (crocodiles and turtles).