The Vyatka is a river in Kirov Oblast and Tatarstan in Russia. It is a right tributary of the Kama. It is 1,314 kilometres (816 mi) long, and its drainage basin covers 129,000 square kilometres (50,000 sq mi).
The Vyatka begins in the northern parts of Udmurtia. It freezes over in the early November and remains so until the second half of April. The Vyatka teems with fish, including bream, roach, tench, sheat fish, pike, European perch, zander, etc.
Freshwater fish are fish species that spend some or all of their lives in bodies of fresh water such as rivers, lakes, ponds and inland wetlands, where the salinity is less than 1.05%. These environments differ from marine habitats in many ways, especially the difference in levels of osmolarity. To survive in fresh water, fish need a range of physiological adaptations.
41.24% of all known species of fish are found in fresh water. This is primarily due to the rapid speciation that the scattered habitats make possible. When dealing with ponds and lakes, one might use the same basic models of speciation as when studying island biogeography.