Brook Trout Spawning

October 17, 2003: Brook Trout
Hi! I'm Iain MacLeod from the Audubon Society of New Hampshire, bringing you Something Wild.

So many animals breed in the spring, it might come as a surprise that there are some notable exceptions. One of these exceptions is breeding right now: the Brook Trout.

Brook Trout, a favorite prize for anglers, lives in cold, clear water. Although they live in streams, they can also be found in some lakes. They love those low temperatures! Which is probably why breeding this time of year is no problem for them.

Brook Trout used to be common in eastern North America, but the introduction of brown trout and small mouth bass have eliminated many native populations.

Brook Trout spawn -fish biologist talk for lay eggs - in the fall. They look for sandy or gravelly areas where upwelling groundwater occurs, usually along a lakeshore or a tributary. Leading up to the spawning season, the males' colors-orange on the sides with a black stripe- become more noticeable. The trout start to congregate, and as they often do this along a lake shoreline or in a stream, you can actually observe this. You would see single fish-those would be females-individually digging shallow nests, where they lay their eggs. There can be several females and nests in an area. The females stay around their nests, but there are males swimming around them, just waiting for the opportunity to zoom into the nests to fertilize the eggs.

The fertilized eggs remain in their sandy beds until the late winter or very early spring. When they hatch, the young trout remain near the shore or the warmer stream areas, feeding on insect larvae and small crustaceans. Because they tend to stay near shore, you can see these youngsters.

So for Brook Trout, the season for love is right now.

If you have a natural history question that you would like answered on Something Wild, email us at somethingwild@ nhpr.org.

Something Wild is a joint production of the Audubon Society of New Hampshire, New Hampshire Public Radio, and the Society for the Protection of New Hampshire Forests. For Something Wild, I'm Iain MacLeod.