Physiological studies on the drawbacks in artificial breeding of Stellate sturgeon, (Acipenser stellatus)

A new formulation of GnRH and synthetic compound of anti-dopamine domperidone was used for the first time in Iran with modern methodology to determine suitable physiological indices for reproduction and to resolve the present problems of artificial reproduction in stellate sturgeon Acipenser stellatus. This study was conducted through three experimental phases on 172 A. stellatus spawners (76 male and 96 female). The first experimental phase was conducted in 2000 on 25 female and 22 male spawners, the second phase was conducted in 2001 on 31 female and 34 male spawners and the third phase was conducted in 2002 on 60 spawners including 40 female and 20 male specimens caught at catch stations in the vicinity of the SefidRud River. Male spawners were treated using single injection method and dual injection method was used in females (Bio- physiological control). Propylene glycole (PG) was administered after the muscular injection to increase the viscosity of the solution during absorption following intra-muscular injection near the second dorsal scute. Depending on the stage of sexual maturity in the brood fish, GnRH at the dose of 5, 10, 15, 20, 30, 40, 50 and 60 µg kg-1 was used in combination with a dose of 1 or 2 mg kg-1 or without of domperidone. The position of GV was used to determine Polarization Index (PI) of sexual maturity in females while in males sexual maturity was determined on the basis of testis and sperms quality. The brood fish under study showed GV in the range of 3.64 to 14.30. The obtained results confirm that reduction of stress during catch, transportation, maintenance and handling and selection of spawners with suitable morphology will result in increased reproduction potential. Analysis of data obtained indicates that male brood fish given a dose of 20 and 30 µg kg-1 GnRH along with 1 and 2 mg kg-1 of domperidone and female brood fish given a dose of 10, 15 and 20 µg kg-1 GnRH along with 2 mg kg-1 of domperidone exhibit the most suitable conditions for spermiation and ovulation and thus in turn respond well to artificial breeding provided they possess GV in the range of 3.64 to 14.30 depending on the water temperature until the germinal vesicle break down (in vivo). The final formulation of GnRH in combination with anti-dopamine domperidone used in the first and second experimental phases was effective in presenting a protocol for artificial breeding in A. stellatus for the third phase of study. On the basis of morphometric measurements recorded in spawners, fork length varied from 117 to 144 cm with a mean of 129.02 ± 1.09 cm, total weight varied from 7 to 15 kg with a mean of 10.53 ± 0.3 kg, age varied from 10 to 16 year with a mean age of 12.75 ± 0.216 year, total weight of eggs varied from 1000 to 2900 g with a mean value of 1923.08 ± 73.8 g, number of eggs per gram eggs varied from 82 to 129 with a mean number of 96.23 ± 1.9 eggs, fertilization percentage varied from 6 to 90 % with a mean rate of 53.37 ± 5.06 %, absolute fecundity varied from 112800 to 24940 eggs with a mean value of 180384.62 ± 5420.9 eggs, Gonado Somatic Index (GSI) varied from 14 to 25.5 with a mean value of 18.131 ± 0.41 and Hepato Somatic Index (HIS) varied from 0.48 to 1.1 with a mean value of 0.8146 ± 0.1. Water temperature at the time of injection varied from 16 to 21 ?C with a mean value of 18.88 ± 0.3 ?C. Hormonal and biochemical indices in female A. stellatus spawners used for artificial breeding in the third experimental phase were also studied. The levels of 17 -Hydroxy progesterone varied from 0.0 to 0.74 ng/ml with a mean value of 0.103 ± 0.013 ng/ml, progesterone varied from 0.017 to 0.263 ng/ml with a mean value of 0.085 ± 0.008 ng/ml, 17 -estradiol varied from 0.579 to 8.31 ng/ml with a mean value 5.86 ± 0.32 ng/ml, testosterone values ranged from 3.8 to 168 ng/ml with a mean value of 83.65 ± 6.3 ng/ml, levels of glucose metabolites ranged from 26 to 108 mg/dl with a mean value of 51.23 ± 2.03 mg/dl and those of calcium ranged from 3.3 to 11.66 mg/dl with a mean value of 8.45 ± 0.25 mg/dl. Thus on the basis of results obtained it is evident that by selecting of brood fish with suitable morphology and identifying correct stage of sexual maturity we can achieve higher production by substituting GnRH with a combination of GnRH and antagonist dopamine (domperidone). Therefore this compound can be recommended as a suitable scientific substitute for pituitary extract and other gonadotrophic analogues in the artificial breeding of A. stellatus in sturgeon hatcheries.

Bibliographic Details

Main Authors:	Bahmani, Mahmoud, Kazemi, R., Vahabi, S.Y., Hallagian, A., Pourdehghani, M., Dezhandian, S., Malekzadeh, R., Mojazi Amiri, B.
Format:	Report biblioteca
Language:	Persian
Published:	Iranian Fisheries Science Research Institute 2005
Subjects:	Biotechnique in artificial breeding, GnRH, Formulation, Domperidone, Antagonist dopamine, Acipenser stellatus, Physiological, Sturgeon,
Online Access:	http://hdl.handle.net/1834/14449
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