Small extensions on fish gills that increase the gill's surface area to improve oxygen consumption.
Material (such as a log, tree, or branches) with a diameter greater than 10 cm and a length greater than 1 meter in the stream. Large woody debris is an important component of westslope cutthroat and bull trout habitat.
The lateral line is a row of fine scales and pores located on the side of a fish. This is a primary sensory organ that is used by a fish to determine its position in the water column and enables a fish to maintain its equilibrium. It is also used by schooling fish to avoid collisions while swimming close together and to turn with the group.
The pattern an organism follows to maximize growth, reproduction and fitness. Examples include: Resident: A fish that completes its whole life cycle in a small tributary stream. Fluvial: A fish that hatches in a small tributary, rears there for 1-4 years, and then migrates out to a larger river to mature. The fish then migrates back to the tributary to spawn. Adfluvial: A fish that is spawn ed in a small tributary, rears for a period of time in the tributary (1-4 years), and then migrates out to a lake where it matures. The fish then migrates back to the tributary to spawn.