CS244397B1 - Method of obtaining eggs in the artificial swabs of tench / Tinca Tinca L. /, trout (Micropterus samonides Lacepede) and the big catfish / Silurus glanis L. / - Google Patents

Abstract

A method of obtaining eggs during artificial spawning of common tench /Tinca Tinca L./, trout perch /Micropterus samoni·» des Lacepede/ and catfish /Silurus glanis L./, the essence of which is that at the time of pre-spawning maturity, the eggs are administered intramuscularly with an analogue of luliberlin, a natural hypothalamic peptide factor, of the general formula I. Glu-His-Trp-Ser-Tyr-D-Ala-Leu-Arg-ProNH-C2H5 in doses of 5 to 20 mg/kg of live weight of the fish. In common tench, eggs reared preferably in water warmed to 21 to 23 °C are administered with this analogue in a dose of 5 to 20 mg/kg of fish weight. The invention uses a synthetic analogue of LH-RH for artificial spawning of eggs in the above-mentioned fish species. Very small doses of an almost pure substance are used, and therefore the incidence of complications is minimal, unlike the pituitary gland used so far, which often ends in death or reproductive cycle disorders requiring removal from the breeding flock.

Description

The invention relates to a method of obtaining eggs during artificial spawning of common tench /Tinca tinca L./, trout perch /Micropterus samonides Lacépède/ and catfish /Silurus glanis L./, which enables maturation, release and increased production of eggs during artificial spawning.

To achieve induced ovulation in freshwater fish eggs, the widely used method is the so-called hypophysation, which is the injection of a suspension of crushed, previously drained fish, usually carp, pituitary glands /kouřil J., Chébera S., Bul, vOrh, Vodnány, 4, 7 /1976/. Although this method currently prevails, there is a certain effort to apply more effective substances of a protein nature, gonadotropic hormones themselves or hypothalamic factors, such as luliberin, hereinafter referred to as /LH-RH/, the administration of which leads to the release of gonadotropins and to the creation of favorable conditions for artificial spawning of eggs /AO 214 369/. The reason, apart from the efforts to use a precisely dosed preparation, is also the fact that when using the pituitary gland, frequent post-spawning mortality or reproductive disorders occur.

In other indications, the widely used hypothalamic factor of porcine origin /LH-RH/ 'Glu-His-Trp-Ser-Tyr-6ly-Leu-Arg-Pro-Gly

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3· shows less suitable for these purposes, species differences probably cause significant differences in sensitivity to this auto factor /AO 214 369/ and /Kouřil et al.: Proc. 2nd Intern· Symposium on Herblovorous F1sh, Novi Sad, 1982. Pp. 70-75/. For further studies, one of the synthetic analogues of the aforementioned peptide factor was selected, which is characterized by higher efficiency towards adenohypophyseal receptors. This is the substance of formula I.

^6lu-His-Trp-Ser-Tyr-b-Ata-Leu-Arg-Pro- /1/ which was prepared and its effects tested by Japanese workers /H. Fujino et al·: Blochea. Biophys. Res. Commun. 57, 1248 /1974/, Fujino H. et al·: Biochim. Biophys· Res. Commun· 60,

406 /1974//. In fish, the effect was tested on crucian carp /Carasslus auratus/ /R. E. Peter: Canad. J. Zool· 58, 1100, /1980//, salmon /Oncorhynchus klsuth/ /J. P. Chang, R. E. Peter: Gen. Coap. Endocrlnol. 52, 30 /1983//, white carp /Hypophthalaicbthys aolitrix/, white carp /Arlsichthys nobilis/, white carp /Ctenopharyngonon idella/ and black carp /Nylopharyngodon piceus/ /Anonyas: Scientia Siní ca 20, 469 /1977//.

The invention relates to a method of obtaining eggs during the spawning of common tench /Tlnca tinca L./, trout perch /Nicropterus saaonldes Lacépede/ and catfish /Silurus glenis L./, the essence of which is that at the time of pre-spawning maturity, the eggs are administered intramuscularly with an analogue of lullberin, a natural hypothalamic peptide factor, of the general formula Z.

p

6lu-Hi s-Trp-Ser-tyr-b-Ala-Leu-Arg-ProNH-C^Hj. /1/ in doses of 5-20 £ig/kg live weight of fish. In common tench, this analogue is administered to the fry reared preferably in water warmed to 21-23° C in a dose of 5-20^ig/kg fish weight.

- 3 Example 1

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The substance used, a synthetic analogue of pig luliberin, was dissolved in physiological solution, the Irag/ml working solution was diluted 10χ and immediately used for indication. The fish, common lin roe, were 4-5 years old, their weight was in the range of 500-1000 g and were kept in laminate tanks with water inflow at a temperature of 20-22°C. The substance was administered intramuscularly to the fish at a dose of 5-80 jUg/kg of fish weight. After 15 hours of application, the fish were checked for egg maturity and readiness for spawning.

Table I presents the results of the injection of the LH-RH analog.

Table X

Effect of a synthetic LH-RH analogue on ovulation in Atlantic salmon.

Substance dose, ^jg/kg/kg Number fish in experiment Ovulating fish %ovulating fish 0 /saline/ 8 0 0 8 1 12.5 2 8 1 12.5 5 8 2 25 10 8 3 37.5 20 8 5 62.5 40 8 1 12.5 80 8 2 25

The most suitable dose range for the synthetic analogue appears to be between 5-20 µg/kg fish weight.

Example 2.

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The optimal dose of the LH-RH analogue was determined depending on the temperature of the water in which the eggs were kept after the application of the peptide. The control group consisted of eggs of common lin, which received a suspension of carp drained pituitary glands at a dose of 5.0 mg/kg body weight of fish ZJ. Kouřil, S. Chábera: Bulo VČRH, Vodňany 4, 7 /1976//. The results are shown in Table II.

Table II

Effect of temperature on ovulation in common linnet larvae after administration of an LH-RH analogue.

Temperature °C LH-RH Analog 20 jugZkg Carp pituitary gland Number ZExtractZ Number fish Number of ovulating fish fish Number of ovules. X pcs X 17 8 1 12.5 8 0 0 19 8 3 37.5 8 0 0 21 8 6 75.0 8 2 25 23 8 5 62.5 8 5 62.5 25 8 4 50.0 8 6 75

The results show that the highest ovulation after administration of LH-RH analogue is achieved at a lower temperature than after administration of extracts from dehydrated pituitary carp. The optimal temperature for ovulation induction by administration of LH-RH analogue is between 21-25 °C _.

Example 3«,

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Table III presents the results of ovulation induction in trout perch after administration of a synthetic LH-RH analogue. Extracts from carp pituitary glands or physiological solution served as controls. A subaxially effective dose of the LH-RH analogue (ovulation results in lin) of 10^ug/kg led to almost complete ovulation in the case of trout perch, similarly to administration of an extract from fish pituitary glands.

Table III

Induction of ovulation in trout perch eggs after administration of an LH-RH analogue.

Substance Dose Number of fish Number of ovulated fish X LH-RH analog 10 µg/kg 7 6 86 Carp Pituitary Extract 4 ag/kg 7 7 100 Physiological equiv in« 7 about about solution objea

Example 4.

Table IV presents the results of ovulation induction in the large ham after administration of an LH-RH analogue. Extracts from drained carp pituitary glands and physiological saline served as controls.

Table IV

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Induction of ovulation in female suckling piglets after administration of LH-RH analogues and extract from dehydrated carp pituitary glands in physiological solution.

Substance Dose Number of fish Number of ovulating fish pcs X LH-RH analog 10 µg/kg 3 3 100 Drained carp hy- pophyses 4mg 3 3 100 Saline solution eq. 3 0 about volume

r·

The invention uses a synthetic analogue of LH-RH to induce egg production in the above-mentioned fish species. Very small doses of the pure substance are used, and therefore the incidence of complications is minimal, unlike the previously used pituitary gland, which often ends in death or reproductive cycle disorders, requiring removal from the breeding flock.

This circumstance is particularly serious for species that are the subject of breeding work (from the species mentioned above), when selection and breeding increase the productivity of fish and at the same time increase the price of this material.

Claims (2)

SUBJECT OF THE INVENTION 244 397 1. A method for obtaining eggs for artificial swallowing of tench (Tinca tinca L.), trout (Micropterus samonides Lacépěde) and catfish (Silurus glanis L.), characterized by administering intramuscularly Lamiberin analogue, a natural hypothalamic, at the time of pre-dawn maturation. of the peptide factor of formula I. Glu-His-Trp-Ser-Tyr-D-Ala-Leu-Arg-ProNH-1H (I) at doses of 5 to 20 µg / kg body weight of fish. 2. A process for obtaining eggs for the artificially spawning of tench according to claim 1, preferably in water of 21 to 23 [deg.] C, characterized in that the analogs are administered to the eggs at a dose of 5 to 20 [mu] g / kg fish weight.