Trout fish, Nyanga's pride

HARARE - Apart from the picturesque mountain scenery and cool temperatures, Nyanga has an added attraction for fish lovers — trout.

Many consider it a delicacy.

The tasty oily fish, related to the salmon, thrives in milder temperatures — and this has spawned trout farming in the area.

Additionally, trout provide a good fight when caught with a hook and line, and are sought after recreationally.

Because of their popularity, trout are often raised on fish farms and planted into heavily fished waters, in an effort to mask the effects of overfishing.

While they can be caught with a normal rod and reel, fly fishing is a distinctive method developed primarily for trout, and now extended to other species.

The biggest of the three trout hatcheries is Claremont followed by Nyanga National Park and Rupurara.
Rainbow trout fish was introduced in the area from the colder countries Canada and Scotland in 1940s — together with potatoes and pine trees.

There are five types of trout fish globally, brooke, tiger, brown and seema, and the more common rainbow trout.

On a visit to Nyanga recently, our crew met Leonard Mususa an employee of the Nyanga National Park hatchery.

Mususa  said trout fish breed in winter when temperatures sometimes fall below zero degrees celsius, especially at night.

“They survive in cool clear streams and lakes where there is a constant supply of fresh water. Young trout are referred to as troutlet, troutling or fry,” Masusa said.

Another park official Joyce Muradzi told how high temperatures last September killed thousands of fish.
Masusa said trout fish cannot survive for more than 10 minutes in stagnant water as the water lacks enough oxygen the fish needs.

Trout that live in different environments can have dramatically different colourations and patterns.
These colours and patterns form as camouflage, based on the surroundings, and will change as the fish moves to different habitats.

“The rainbow trout in Nyanga breeds once a year in winter and each fish can lay over 400 eggs during this season from May 15 to the end of August,” said Masusa.

The eggs need at least 25 days to hatch.

“In order to maximise production, we mix male and female trouts in winter for them to mate. We then engage artificial fertilisation process,” he said.

In summer they separate male from female to avoid fighting and to stimulate them.

“Female trout fish have round shaped mouths, while males have hooked lower jaws,” he said.

The entire process of trout farming needs a lot of precision and resources such as cash and skilled labour.

Troutlets are fed on fry powder.

“When troutlets weigh about 20 grammes we introduce them to trout starter before giving them pellets and finally trout finisher,” he said.

Basically there are three end-products of trout fish and these include hot smoked trout fillet, smoked salmon trout and fresh fillet.

Farmed trout and char are also sold commercially as food fish.

“We slaughter fish when they weigh about 200 grammes and above as these sizes are on demand on the market.
“At this size the fish is called table trout,” he said.

A kilogramme of trout costs eight dollars at the hatchery.

Some of the fish is sold to local hotels, with the remainder being exported.

A number of fish ponds are at the hatchery and each pond contains between 7 000 to 50 000 fish of the same size.

An adult trout fish can weigh up to two kilogrammes and the maximum recorded life-span for a rainbow trout is 11 years.

Trout rearing is expensive, and for this reason, only a few firms have the resources to run hatcheries
A fish-meal is costly and about 250 000 trout need about 10 tonnes of feed.

Trout fish is vulnerable to diseases such as pop eyes and pinhead, caused by wrong feed, among others.
As if this is not enough, predators prey on trout fish and these include eels and the kingfisher eagle just to mention a few. — WeekendPost

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