The Rainbow Trout

By

The rainbow trout (Oncorhynchus mykiss) (engl. rainbow trout) is not native to Europe and originally comes from North America west of the Rockey Mountains. Nevertheless, it can be found in many lakes, river systems and ponds in Germany and can also be bought in almost every supermarket.

Table of ContentsSalmon trout a marketing nameDanger of confusionWorld records and maximum sizeWandering forms SteelheadDistribution and originLawning seasonSafety time and minimum sizesBehaviour and natural foodBait for rainbow trout and fishing techniquesIn pond systemsFishing tackle for trout fishingRainbow trout in aquacultureThat is why rainbow trout is reproduced in Germany Non-rainbow trout as an edible fish

Salmon trout a marketing name

The so-called salmon trout is nothing other than an ordinary rainbow trout.    Salmon trout is merely a trade name for particularly large rainbow trout which have been fed on carotenoid-containing feed and thus acquire their pink flesh colour. This strongly reminds of a salmon and of course “salmon trout” simply sounds better to the consumer. The slightly higher price per kg of fish results from the slightly more expensive feed and above all from the considerable additional work that goes along with keeping the fish longer. The growth of the fish decreases strongly with age and therefore the additional expenditure of feed is also higher.

By the way, even farmed salmon get their distinctive flesh colour this way. Genuine wild salmon can be even more extremely coloured and have a nearly red meat.      Trout naturally get their colour from eating crustaceans. It is therefore possible that, for example, a trout in a stream with many brown crabs will have a natural red to pink flesh colour.    Large trout, on the other hand, naturally rarely have such a colouring, as they tend to feed on small fish.

Danger of confusion

A danger of confusion exists especially with the brown trout. The appearance of the rainbow trout can vary greatly in natural waters and the otherwise so striking pink rainbow shimmer can disappear. While the trained eye can quickly distinguish an inserted rainbow trout from a brown trout by means of eaten off fins or the very small mouth. This is difficult with fish that have been in the water for a long time.    A clue is the high number of black dots, which also appear on the fins. Also a rainbow trout never has red spots, but only the brown trout.

World records and maximum size

The world record of a rainbow trout is a massive 21.77 kg and was caught in Canada and was almost exactly one meter long.

Hiking forms Steelhead

Just as our brown trout can be found as lake and sea trout, rainbow trout also have so-called hiking forms. These can be found in brackish water or lakes and grow to considerable sizes. For spawning both forms move back into streams. Mostly they survive this strenuous migration and return to brackish water or the lake.

Distribution and origin

Originally the rainbow trout comes from North America. Due to its greater robustness, temperature tolerance and faster growth than the brown trout, it is a popular set fish and is often caught in water. About the

Spawning season

The spawning season of the rainbow trout is similar to that of the brown trout in spring, but somewhat later.

Closed season and minimum sizes

Rainbow trout often have a closed season to make the brook trout more beautiful as well, for example, in streams in general is not fished for trout. Please note that many waters may have different closed seasons and minimum sizes. These are often written on the permit.

Behavior and natural food

The natural food of the rainbow trout consists mainly of small crustaceans, as well as insect larvae and smaller fish. Animals of appropriate size

Bait for rainbow trout and fishing techniques

Trout bite on anything that moves or turns. So spinners are very successful but also small plugs and rubber fish. Spinners and last but not least flies are also among the top lures for rainbow trout. As natural baits bait fish, earthworms, bee maggots and even corn have proven successful. It is often important to have a long leader, so that the baits move in mid-water by current.

In pond systems

Often only natural baits are allowed in pond systems. Therefore all the above mentioned spinning lures are omitted. However, trout dough is always permitted, which is brought into shape and offered at a spirolino or special pose mounting.

Trout fishing tackle

Again, a distinction is made between fishing in natural waters and in ponds.    For natural waters we recommend light spinning rods and a matching small spinning reel (link to market overview >>) for spin fishing. Fly fishing for rainbow trout is also very successful. Very light fly rods are also suitable for this.

Trout Rods some recommendations

If you want to go fishing with natural bait, almost any rod that is not too strong will do, even feeder rods. For pond systems there is an extra assortment, which allows fishing with the very long mounts for trout dough fishing. The rods for this are usually very long (over 3 m) and have a soft parabolic action.

Rainbow trout in aquaculture

In aquaculture or fish farming the rainbow trout has an important role in Germany and Europe. On the one hand, set fish are produced, but also as food fish.    Many trout farms are also equipped with smoking ovens for direct refinement of fillets or whole fish.

The fish are usually fed with high protein pellets.    The negative environmental impact of a trout farm is often kept within limits because certain waste water treatment facilities are prescribed. This means that the environmental impact is less than, for example, that of a sewage treatment plant. The high protein feed, on the other hand, is somewhat more problematic. Trout have only a very limited digestion of starch and can only absorb it in a digested form. In pelleting, this is achieved by high pressure and steam. The main energy source in trout feed is therefore fat, which the animals can digest better.

This is why rainbow trout do not reproduce in Germany

With few exceptions, rainbow trout do not reproduce in Germany, even though the number of reproducing animals is increasing. One of the reasons is that almost all fish of the appearance type (phenotype) bred in Germany are female. Thus, in almost all waters male animals are missing for reproduction. The main reason is that female animals grow off better and are not as aggressive as males.    There are two techniques to achieve an almost 100% female phenotype or infertile offspring. Firstly, after fertilisation of the eggs, at a critical stage of egg development, a shock in the form of increased pressure on the eggs can cause the offspring to become triploid.

The other possibility is due to the fact that sexual differentiation in fish is significantly more unstable than in humans. Thus, hormones or temperature processes can be used to masculinise a genetically female animal with two X chromosomes (gonosomes) at the developmental stage.    If you cross this animal, which has male gonads but female sexual organs with a normal female animal, the offspring is almost 100% female (XX+XX -> XX).

The hormone-treated animals are only the parent animals and are NOT traded! This technique is also no longer used in the EU, only temperature procedures. The whole thing is NOT A GENEARTICAL TECHNOLOGY, because no genes are changed or manipulated here.    What about the animals from the supermarket, which come from non-EU countries, nobody knows. Look where your trout come from (must be written on the packaging) and think about whether the country is in the EU.

It may surprise you that they are not 100% the reason is simply the unstable development of the sex (sexual differentiation) of fish.    Because even among the purely genetically female animals an animal can develop into a phenotypic and fertile male.

By the way, the whole thing also works the other way round, so a genetic male (XY) can be feminized and together with a normal male (XY) produces partly genetic “super males” (YY).    Together with a normal female (XX) these males ensure that the offspring consists almost exclusively of males (XY). This technique is used with other fish species. Also for example with carps in Australia, so that they can no longer reproduce.

Even in nature this happens quite naturally and one or the other “Suppermännchen” of various fish species swim in our waters. But as these fish are often very aggressive, they will probably be removed quickly by us anglers.

Rainbow trout as food fish

Rainbow trout are a popular food fish and have a firm rather fatty meat. Therefore they are also very suitable for smoking. Also very popular is the Müllerin trout with a thin breading of flour. In almost all restaurants the offered trout are rainbow trout.

Leave a Comment