Habitat refers to an area where a fish is found and provides the necessary requirements for the fish to live and grow including cover, food, and appropriate temperatures. Habitat requirements are species specific and change throughout the species lifetime and seasons.
The undefended area a particular species uses to gain resources, which varies by season and age.
The ability of an adult fish to locate where it was born and migrate back to that stream to spawn. Fish have the ability to recognize the distinctive chemicals present in the stream in which they were born. These chemical cues are one way fish are guided back to that tributary for spawning.
A hybrid is a combination of two different species. For example, when a cutthroat trout spawns with a rainbow trout, the resulting fry are hybrids sometimes called "cuttbows". Many hybrids cannot successfully reproduce, however those that can are detrimental because it leads to further hybridization with remaining native fish. hybridization is one of the reasons for decline of native fish, including westslope cutthroat trout that hybridize with introduced rainbow trout and bull trout that hybridize with introduced eastern brook trout.