Classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Musteliade
Genus: Lontra
Species: L. Canadensis
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Musteliade
Genus: Lontra
Species: L. Canadensis
History
Species Description: (Reed-Smith 2012)
- North American river otters are endothermic, homeothermic and have a bilateral symmetry
- Otters are a member of the weasel family, Musteliade.
- They live approximately 8 to 9 years in the wild, weigh 5-14 kg on average with a body length of 55-80cm and tail length of 30-50cm, the males are larger than the females by about 5 % to 17 %.
- The modern day otter evolved into semi-aquatic carnivores adopting a long slender body, short legs, webbed feet, rudder like tail, and open-close nasal cavities, and a water proof short haired, dense fur coat. In addition, the otters have decreased lung lobulation and a shortened trachea that are adaptations to improve oxygen extraction efficiency for living primarily in aquatic conditions (Kruuk 2006).
![Picture](/uploads/2/5/8/0/25801510/1385173.png?372)
There are several subspecies of River Otters and their locations represented in this graph
1. L. c. canadensis - typically the smallest of the subspecies
2. L. c. lataxina - typically smaller and has a lighter coat
3. L. c. pacifica - lighter in nature and inferior portion of the feet almost completely naked
4. L. c. sonora - larger sub species with a characteristic long hind foot
5. L. c. mira- largest of subspecies, a large angular skull
6. L. c. periclyzomae - mid range in terms of size, smaller than mira
7. L. c. kodiacensis - smaller subspecies, with unique cranical charactersistics
1. L. c. canadensis - typically the smallest of the subspecies
2. L. c. lataxina - typically smaller and has a lighter coat
3. L. c. pacifica - lighter in nature and inferior portion of the feet almost completely naked
4. L. c. sonora - larger sub species with a characteristic long hind foot
5. L. c. mira- largest of subspecies, a large angular skull
6. L. c. periclyzomae - mid range in terms of size, smaller than mira
7. L. c. kodiacensis - smaller subspecies, with unique cranical charactersistics
Evolution:
Location: (Boyle 2006)
- There are 13 species of otters that have a very different physiology suggesting a rapid divergence in early history. Their habitat, behaviour and food habits determine their distinct physiology. The otter evolved from another weasel species, Paralutra jaegeri , this fossil record dates back to approximately 25 million years ago and the North American River Otter and Eurasian otter were thought to have diverged about 12 million years ago based on DNA evidence (Reed-Smith 2012).
- Early otters had sharp cutting teeth, speculating a predominantly fish diet. North American River Otters have highly evolved teeth and feet making them even further specialized fish hunters and the best representation of the early species of otters. Their teeth are sharp and have defined molars for gripping and slicing into slippery fish, and their feet have well developed interdigital webs on all feet with well defined, non retractable claws making them prime predators to fish species (Kruuk 1995).
Location: (Boyle 2006)
- River Otters are found throughout most parts of North America. Although they are classified as "river otters", they can be found in rivers, lakes, small streams, and rocky seas (approximately 2-78 kilometers of waterway). Can tolerate high and low latitudes and both freshwater and saltwater environments. 11 of the 13 species live in predominately freshwater, although 7 of these can also live in seawater, suggesting that the ancestors of otters were of freshwater origin.
- In the mid twentieth century, due to invasive human action, they became more selective in their environments and dispersion decreased. Currently, there are large scale reintroduction programs in place decreasing the pollution and poaching by humans that forced this species relocation and subsequent decline in population. The river otters reside primarily in dens or 'holts' close to a body of water (Kruuk 1995).
![Picture](/uploads/2/5/8/0/25801510/568475.png?642)
The image illustrates the decline in North American River otter distribution due to unregulated fur trapping and European settlement beginning in the 1700s
** Primary references for this page:
1. Boyle, S. (2006, September 2). North American River Otter (Lontra canadensis): a technical conservation assessment.
[Online]. USDA Forest Service, Rocky Mountain Region. Available: http://www.fs.fed.us/r2/projects/scp/
assessments/northamericanriverotter.pdf [March 2, 2014].
2. Kruuk, H. (2006). Otters: ecology, behaviour and conservation. Great Clarendon St. NY: Oxford University Press
3. Kruuk, H. (1995). Wild otters: predation and populations. Walton St. NY: Oxford University Press.
1. Boyle, S. (2006, September 2). North American River Otter (Lontra canadensis): a technical conservation assessment.
[Online]. USDA Forest Service, Rocky Mountain Region. Available: http://www.fs.fed.us/r2/projects/scp/
assessments/northamericanriverotter.pdf [March 2, 2014].
2. Kruuk, H. (2006). Otters: ecology, behaviour and conservation. Great Clarendon St. NY: Oxford University Press
3. Kruuk, H. (1995). Wild otters: predation and populations. Walton St. NY: Oxford University Press.