Anal bladder

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The anal bladder is a rectal respiratory organ of some pond and aquatic turtles.

Anal bladder of the turtle: 1 cloaca opening, 2 paired anal bladders, 3 interior of the anal bladder with long fimbriae

Functions

As a multifunctional organ, the anal bladder is part of the cloaca of some pond and water turtles . It is made up of a pair of systems on both sides of the rectum that can stretch deep into the body. The anal bladder can be filled with water and emptied under muscle control. As a respiratory organ (cloaca breathing), it helps the animal to breathe underwater, both when diving and during cold rigor . For this purpose, it is equipped with numerous small surface structures (fimbriae) with blood vessels that can absorb oxygen. The specific weight of the body can also be adjusted to that of the surrounding water with the anal bladder, so that the animal can move horizontally more easily when diving. When laying eggs, the nest site is softened with water from the anal bladder before digging. The anal bladder also serves as a passive defense against enemies. Ejected rectal residues and smelly gland secretions can lead to unpleasant odors. When the animal lies quietly on the bottom of the aquarium, a pumping in and out of water through the anal bladder can be observed. The turtle's anal bladder, along with breathing through the mouth and throat, is a system for anaerobic glycolysis .

The cloacal breathing through the anal bladder is different in turtle species. A particularly strong form can be found in the Australian Fitzroy river turtle Rheodytes leukops . Your anal bladder is 10 cm in size and 26 cm in length. The frequency of cloaca contraction for breathing is 15–60 times per minute.

Individual evidence

  1. ↑ FitzGibbon, Sean I. Franklin, Craig E .: The importance of the cloacal bursae as the primary site of aquatic respiration in the freshwater turtle, Elseya albagula . Royal Zoological Society of New South Wales. 2010-04. doi : 10.7882 / AZ.2010.016
  2. ↑ P. Lemell. General anatomy of the tortoise (Chelonia). Biology Center Linz / Austria
  3. ↑ Craig E. Franklin. Aquatic respiration and diving in the freshwater turtle, Rheodytes leukops. 2000 [1]
  4. ^ Toni E. Priest and Craig E. Franklin. Effect of Water Temperature and Oxygen Levels on the Diving Behavior of Two Freshwater Turtles: Rheodytes leukops and Emydura macquarii. Journal of Herpetology, Vol. 36, No. 4, pp. 555-561, 2002