Ichthyomyini

The fish rats ( Ichthyomyini ) are a tribe of the New world, which is characterized by an extraordinary adaptation to aquatic life. The species are carnivorous and feed mainly on aquatic insects and crustaceans also the larger of small fish. Fish rats have many parallels to the swimming rats Australia and New Guinea, but they are not closely related, but have become quite similar in convergent evolution.

Fish rats reach depending on a head-body length of 9-21 cm, the tail is 9-19 inches long. Their fur is dark brown or grayish black, the underside is lighter. Among the adaptations to aquatic life include reduced eyes and ears and nostrils closed. The hind feet are enlarged and the toes connected with webbed, the tail is often flattened.

Fish rats are native to Central and northern South America, their range extends from southern Mexico to northern Brazil and Peru. Their habitat is usually the banks of rivers, sometimes wetlands. They come here before, at altitudes up to 3800 meters. They build their shelters on the shore and go in the water hunting for prey.

The fish rats include five genera with 16 species:

• Neusticomys, 5 types
• Ecuador Fish rat ( Anotomys leander )
• Chibchan Water Mouse ( Chibchanomys ), 2 species
• Actual fish rats ( Ichthyomys ), 4 types
• Central American water mice ( Rheomys ), 4 types

The genus Neusticomys shows the lowest, the Central American Water mice, the highest adaptations to aquatic life.