Coldwater Fish Species

Brook Trout

Adam Nidoh

Brook Trout

Salvelinus fontinalis – Native
Family: Salmonidae

Brook Trout are generally dark green to brown with dark colored markings. The sides are lighter in color with yellow and red dots and an orange belly with a black streak. They prefer cold clean streams, and do not tolerate temperatures over about 65° F. Spawning occurs in early through late fall, when females create a depression in the gravel at the bottom of a stream. Depending on the size of the fish, they may produce only a few hundred eggs or several thousand. Once the eggs are fertilized, they are covered with another layer of gravel and will hatch in late winter or early spring. Brook Trout’s diet consists of insects, crustaceans, and small fish.

 

Brown Trout

Jesse Filingo

Brown Trout

Salmo trutta – Nonnative
Family: Salmonidae

Brown Trout are native to Europe and were first introduced to the U.S. from Germany in 1883. Brown Trout are an olive green to brown color on top that transitions to yellow and off-white color along the bottom. Black spots cover their body, but they have few if any spots on their tail, unlike other trout species. Brown Trout are a coldwater species, and their optimal water temperature is around 50 to 60° F. Spawning takes place in fall. Females create a depression in the gravel at the bottom of the river and then deposit their eggs there. The eggs then hatch in the spring, and no parental care is given. Brown Trout tend to feed on insects, crayfish, and fish. Larger Brown Trout may even eat small mammals, salamanders, frogs, and turtles.

 

Rainbow Trout

Adam Nidoh

Rainbow Trout

Oncorhynchus mykiss – Nonnative
Family: Salmonidae

Rainbow Trout are native to western North American but have been introduced to prtions of the Upper Delaware River that have been cooled by dam releases. They have silver sides with a pink or reddish horizontal band, and their back is blue green with black spots. Rainbow Trout prefer clean and well-oxygenated water that stays below 70° F. Spawning occurs in spring, and females create a nest depression by forcefully moving gravel with their bodies and fins. After females lay their eggs into the gravel, no more parental care is given, and the eggs hatch in a couple of weeks. The Rainbow Trout’s diet consists of both aquatic and terrestrial insects and small fish.

 

Fishing catch your Fancy?

Fishing on the Upper Delaware

 

• 

  Migratory Fish Species

  Learn about the Migratory Fish Species found in the Upper Delaware River.

• 

  Nongame Fish Species

  Learn about the Nongame Fish Species found in the Upper Delaware River.

• 

  Other Gamefish Species

  Learn about the Gamefish Species of the Upper Delaware River.