RU2773698C1 - Method for erecting redds and laying brook trout eggs - Google Patents

Abstract

FIELD: fish industry.

SUBSTANCE: invention relates to fisheries, in particular to the artificial breeding of salmon fish, and can be used to reproduce stocks of brook trout Salmo trutta caspius Kessler. The method for artificial breeding of brook trout includes the preparation of redds and artificial fertilization of eggs at fish hatcheries using a “dry method”, transportation of eggs to spawning sites and laying eggs in the soil of streams. At the same time, redds are arranged manually in spring streams from river pebbles and pebbles at a distance from each other. Before laying eggs, the redds are dug up and loosened, and the eggs are laid using a transparent plastic 1.5-liter bottle with a cut bottom and side perforation. To do this, first, portions of fertilized caviar are placed in the bottle from the side of the cut bottom, then the bottle with caviar is smoothly lowered into the water upside down with the neck covered by the hand. Then the bottle is immersed to the very top of the hillock and the hand is removed, and the neck is stuck into the pebble soil. At the same time, water enters through the perforation into the bottle, which agitates the caviar, and the caviar settles in its lower part. After that, the bottle is slowly lifted and the caviar is poured onto the pebble, at the same time the caviar is covered with homogeneous pebbles on top.

EFFECT: increasing the efficiency of artificially arranged brook trout redds, creating optimal conditions for the normal development of eggs and larvae, which ensures a high degree of restoration of natural stocks of brook trout.

1 cl, 2 dwg

Description

The invention relates to fisheries, more specifically to the artificial breeding of salmon fish, and can be used to reproduce stocks of brook trout Salmo trutta caspius Kessler.

A known method of incubation of eggs in artificial nests-incubators installed in rivers [1]. The method includes artificial insemination of eggs at fish hatcheries by the “dry method”, transportation of eggs to spawning grounds, laying of eggs at the “eye” stage in artificial nests-incubators, which are installed on threshold-erratic sections of rivers open from ice at the end of March. This technology is not entirely suitable for mountain brook trout, it is very difficult to apply it in small spring feeding streams, where trout mainly lives and breeds.

There is a known method of breeding fry of the river form of trout (larvae) in trout hatcheries and their subsequent release into rivers to replenish the natural stocks of trout [2]. However, scientific research has proven that this method of breeding trout is ineffective, because of the weak, defenseless fry released at an early age, in natural conditions full of dangers, only an insignificant part (less than 1%) survives to the commercial size.

The purpose of the invention is to increase the efficiency of artificially arranged spawning grounds for brook trout (Salmo trutta caspius Kessler).

This goal is achieved by the fact that in the method of artificial breeding of brook trout, including the preparation of spawning mounds, artificial fertilization of eggs at fish hatcheries by the "dry method", transportation of caviar to spawning sites, laying eggs in the soil of streams, spawning mounds are arranged manually in spring streams from a river pebbles and pebbles at a distance from each other, while before laying the caviar, the hillocks are dug up and loosened, and the eggs are laid using a transparent plastic one and a half liter bottle with a cut bottom and side perforation, for this, first, portions of fertilized caviar are placed in the bottle from the side of the cut bottom, then the bottle with caviar is smoothly lowered into the water upside down with the neck covered by the hand, then the bottle is immersed to the very top of the hillock and the hand is removed, and the neck is stuck into the pebble soil, at the same time, water enters the bottle through the side perforation, which stirs the caviar, and the caviar settles in its lower part, after which the bottle u slowly raise and pour the caviar on the pebbles, at the same time sprinkle the caviar on top with homogeneous pebbles.

In FIG. 1 shows the core section of a brook with artificially equipped spawning mounds in a section along its channel; in fig. 2 - scheme of laying brook trout eggs into the spawning mound using a plastic bottle with caviar.

Spawning mounds 1 of brook trout consist of a layer of gravel 2, on top of which eggs 3 of brook trout are laid using a transparent plastic one and a half liter bottle 4 with a cut bottom 5, with perforated sides 6 and a wide neck 7. On top of the layer of laid eggs 3 of brook trout, a small filling of river pebbles 8.

The method of artificial breeding of brook trout is carried out and works as follows.

First, on the rod section of a mountain stream, the places for laying artificially equipped mounds are marked. The distance between the hillocks should be at least 1.5 m, optimally from 1.5 to 5 m or more, depending on the hydrological and geomorphological conditions of a particular section of the river (stream). Then, with the help of a pitchfork and a rake, the river pebbles are collected in layers at the places of the future mounds, the thickness of the pebble layer of each mound is approximately 10-15 cm. This improves the aeration of the spawning grounds and enhances their washing. On top of the pebble layer, a layer of river pebbles is poured (approximately the same size - 40-60 mm). In this order, the required number of spawning hillocks is arranged, and the number of hillocks on one rod or stony-pebble section of a mountain river can be from 3-5 or more. Transportation of caviar from a fish factory to a spring stream or river is carried out by passenger cars in a foam thermos. At the same time, the laying of roe of brook trout in the soil of streams is carried out from February to March (upon reaching the “eye” stage). Before laying the roe of the brook trout, the pebble soil of the mounds 1 is loosened with a rake and a pitchfork with metal handles. After that, the eggs 3 are laid in the pebble soil of the mounds 1 in small portions (up to a hundred eggs) using a transparent plastic one and a half liter bottle 4 with a cut bottom 5, with a side perforation 6 and a wide neck 7. First, a portion is placed into the bottle 4 from the side of the cut bottom 5 caviar 3. Next, the bottle 4 with caviar is smoothly lowered into the water upside down. At the same time, its neck is covered with a hand (a palm moistened with water), which prevents caviar from falling out of it. Then, having immersed the bottle 4 to the very top of the mound 1, the hand is removed, and the neck 7 is stuck into the pebble soil. Through the perforation 6, water enters the bottle 4 and stirs up the caviar. After the caviar 3 stirred up in the bottle settles in its lower part, the bottle 4 is slowly lifted and the caviar 3 is poured onto the stones, at the same time large and uniform pebbles 8 are sprinkled on top of it. Thus, the caviar 3 of the brook trout is laid in all the prepared spawning mounds 1.

Caviar laid in pebble soil is protected from being carried away by water flow and from predators (river fish, dipper, etc.), for this, the depth of laying eggs must be maintained within 5-10 cm from the soil surface of the mounds. Between pebbles and small rounded stones, fertilized eggs at the “eye” stage develop rapidly and after 5-15 days larvae hatch from it. At first, the larvae feed on the nutrient reserves of the yolk sac. After 20-27 days, larvae grow into fry of brook trout, which swim out from under the substrate into the external aquatic environment. Under (relatively) large stones in the spawning grounds, the larvae find the necessary shelters. Further, trout fry, adapted to the conditions of a mountain stream, grow to the stage of adults (producers).

Produced by the proposed method spawning mounds of stone soil create optimal conditions for spawning and reproduction stocks of brook trout.

The method of artificial breeding of brook trout can be most effectively used in the mountainous areas of spring rivers and streams.

Literature

1. Patent of the Russian Federation 2386248. A method of incubation of eggs in artificial nests-incubators installed in rivers. / Pavlov D.S., Skorobogatov M.A. et al. Bull. No. 11, publ. 04/20/2010.

2. ribovodstvo.com/books/item/f00/s00/z0000008/st023.shtml

Claims (1)

A method of artificial breeding of brook trout, including the preparation of spawning mounds and artificial fertilization of eggs at fish hatcheries by the “dry method”, transportation of caviar to spawning sites, laying eggs in the soil of streams, characterized in that spawning mounds are arranged manually in spring streams from river pebbles and pebbles at a distance from each other, while before laying the caviar, the hillocks are dug up and loosened, and the eggs are laid using a transparent plastic one and a half liter bottle with a cut bottom and side perforation, for this, first, portions of fertilized caviar are placed in the bottle from the side of the cut bottom, then a bottle with caviar gently lowered into the water upside down with the neck covered by the hand, then the bottle is immersed to the very top of the hillock and the hand is removed, and the neck is stuck into the pebble soil, at the same time, water enters the bottle through the perforation, which stirs up the caviar, and the caviar settles in its lower part , after which the bottle is slowly lifted and sprinkling caviar on a pebble, at the same time sprinkle caviar on top with homogeneous pebbles.

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