Brown trout

Brown trout

Salmo trutta

Common name:

Brown trout

Scientific name:

Salmo trutta

Alternative common names:


Description:

Brown trout has a fusiform (or spindle-like) body shape. It is silver to olive-brown andyellow in colour, with small scales and large red spots covering the body. In South African dams, this species can grow up to 75cm in length and weighover 6kg, whereas in rivers, smaller specimens are found. This fish feeds on invertebrates, insectlarvae, aerial insects and molluscs, as well as the occasional fish and frog.

Additional Information


Where does this species come from?

Europe.

What is its invasive status in South Africa?

NEMBA 2020 Category 2 in national parks, provincial reserves, mountain catchment areas and forestry reserves specified in terms of the Protected Areas Act and Fish Sanctuary Areas. NEMBA 2020 Category 2 for introduction into rivers.

Where in South Africa is it a problem?

Eastern Cape, Drakensberg in KwaZulu-Natal, Mpumalanga, southern Cape and south-west Cape.

How does it spread?

Migrates from lakes into rivers or streams to spawn.

Why is it a problem?

Brown trout have been implicated in reducing indigenous fish populations (especially other salmonids) through predation, displacement and food competition.

What does it look like?

Description: The brown trout is a medium-sized fish, growing to 20kg or more and reaching lengths of about 100cm in some localities, although in many smaller rivers, a mature weight of 1kg or less is common. It reaches an average length of 40-80cm with a maximum length of 140cm and a weight of 27.2kg. It has a very small scales and small fins, including a lobate adipose.

Habitat: Brown trout form stream-resident populations, typically in alpine streams, but sometimes in large rivers. They are more likely to be found near submerged rocks and logs, undercut banks and overhanging banks. They can also be found in heavy and strong currents.

Breeding: A typical female produces about 2 000 eggs per kilogram of body weight at spawning. It breeds in autumn or early winter.

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