Brown Trout, Salmo Trutta

browntrout

 

Distribution:

map

Description:

Brown trout have an olive to golden brown back and lightening to a white belly.  Sea run and large lake individuals have a silvery colouration.  The body has numerous black spots on the back and sides which extend below the lateral line mostly near the head, and the sides also have red spots with bluish halos.  Juvenile brown trout have 9 - 14 parr marks and red spots along the lateral line.  The adipose fin is generally a redish-orange, dorsal fin yellowish with black spots,  the caudal is squared and caudal peduncle roboust.  Maxillary to below last half of eye on 5-inch fish, and extending  well beyond eye in larger fish; gill cover usually with many spots; branchiostegals usually 10; dorsal fin rays usually 9; vomerine teeth well developed.

Biology:

Brown trout prefer well oxygenated streams and lakes, and have a optimun temperature of 18.3 - 23.9 C.  Spawning occures in late fall in headwater streams and over rocky shoals in lakes.  The female excavates a shallow nest (redd) for egg and sperm deposition, and then covers it with gravel.  The diet of brown trout include aquatic and terrestrial insects, crustaceans, amphibians, rodents, and fish.

browntrout