Above: The water resistant hairs of the European river otter.
(European River Otter, Mark Sisson, www.arkive.org) |
Above:The webbed toes common to otter species. A unique anatomical adaptation.
(European river otter, Ingo Arndt, www.arkive.org) |
This page is dedicated to describing the anatomy and physiology of the North American river otter (Lontra canadensis) and the European river otter (Lutra lutra). Entries on this page are descending in order of food movement through the body, starting with the mouth and teeth and ending in excretion.
Lontra Canadensis
Dentition
A lot about diet can be determined by how dentition has adapted to suit it. In the case of the North American River Otter, the teeth have been adapted to its largely fish based diet.
Upper set of teeth
(on each side): 3 incisors 1 canine 4 premolars 1 molar |
Lower set of teeth
(on each side): 3 incisors 1 canine 3 premolars 2 molars |
It is also notable that the 4th premolars are carnassial teeth. These teeth are essentially elongated to allow for shearing action while breaking apart meat.
(Reed-Smith, 2001)
(Reed-Smith, 2001)
A Special GI Adaptation
It has been suggested that the North American river otter has a special intestinal defense system to help protect their intestines from lacerations. Excessive mucous production acts to protect the intestinal walls from fish scales and other sharp food by-products.
(Reed-Smith, 2001)
(Reed-Smith, 2001)
Digestive Morphology
Intestines and Accessory Organs
There is not much variation in the look of the intestinal wall progressing from the jejunum, through the ileum and large intestine (Baitchman and Kollias, 2000).There is no caecum, likely due to their largely carnivorous diet (Baitchman and Kollias, 2000).
Lutra lutra
Due to their very close relationship, the digestive anatomy of the two species of otter are extremely similar. That which is outlined above can also be applied to the European river otter.
References
1. Arkive. 2015. Common otter (Lutra lutra). Available: http://www.arkive.org/common-otter/lutra-lutra. Accessed March 2, 2015.
2. Arkive. 2015. North American otter (Lontra canadensis). Available: http://www.arkive.org/north-american-otter/lontra-canadensis. Accessed March 2, 2015.
3. Baitchman, E. J., G. V. Kollias. 2000. Clinical anatomy of the North American river otter (lontra canadensis). J. Zoo. Wildlife. Med. 31(4):473-483
4. Larivière, S., L.R. Walton. 1998. Lontra canadensis. Mamm. Species. 587: 1-8
5. Reed-Smith, J. 2001. North American river otter. 2nd ed.
2. Arkive. 2015. North American otter (Lontra canadensis). Available: http://www.arkive.org/north-american-otter/lontra-canadensis. Accessed March 2, 2015.
3. Baitchman, E. J., G. V. Kollias. 2000. Clinical anatomy of the North American river otter (lontra canadensis). J. Zoo. Wildlife. Med. 31(4):473-483
4. Larivière, S., L.R. Walton. 1998. Lontra canadensis. Mamm. Species. 587: 1-8
5. Reed-Smith, J. 2001. North American river otter. 2nd ed.
Banner: North American river otter, Thomas D. Mangelsen, www.arkive.org; North American river otter, Tom and Pat Leeson, www.arkive.org; North American river otter, John Cancalosi, www.arkive.org; Common Otter, Laurie Campbell, www.arkive.org; Common otter, Henry Ausloos, www.arkive.org; Common otter, Laurie Campbell, www.arkive.org; Common Otter, Jorg and Petra Wegner, www.arkive.org; Common otter, Wild Wonders of Europe, Campbell, www.arkive.org; North American river otter, Gordon and Cathy Illg, www.arkive.org