Brown trout
(Salmo trutta)
Brown trout are medium to large silver-brown fish. Within the species there is great variety in size and in coloration. They are present in rivers all year round.
Trout swim against the current to keep their position in the stream, and dart out to catch passing insects and other invertebrates that either live in or fall into water, as well as small fish. In winter, smaller trout hide under rocks during the day but emerge to feed at night.
Its predators include kingfishers and dippers when small, then otters, cormorants and goosanders when larger. Trout are found in the River Endrick and its tributary streams
Fascinating fact:
Partly depending on its early growth rate, a trout can either migrate to sea (in which case it is called a sea trout) or stay its entire life in a river (in which case it is a brown trout).
Trout eggs are laid in the gravel of fast-flowing streams. Young trout live in shallow streams, moving to deeper water as they grow. If they grow fast, they will remain in the rivers as brown trout, but slow-growing fish may migrate to sea for 1–2 years. Brown trout usually live in deeper river water than salmon.
Like salmon, trout usually return to the stream where they were born to breed. Sea trout usually spawn just once, but brown trout may breed several times. Sea trout numbers are declining.
Did you know
Brown trout need very clean and well-aerated water, and sea trout are vulnerable to parasites from fish farms (especially sea lice).