Publication Date:
2021-05-19
Description:
The objective of this study was to determine the effect of human chorionic gonadotropin (hCG) on sexual
maturation, plasma sex steroids [17β-estradiol, (E2) and 17α-hydroxy progesterone (17α_OHP)] and thyroid
hormones (triiodothyronine, T3 and thyroxin, T4) levels in upstream - migrating Caspian lamprey. During the
experiment, 36 fish (24 females and 12 males) in spring 2013 and 36 fish (24 females and 12 males) in fall 2013 were
collected from the Shirud River estuary in Mazandaran Province, the Southern Caspian Sea during their upstream
migration to the freshwater. All fish were injected with hCG at the doses of 1000, 1500 and 2000 IU.kg BW-1. The
injection was a two - step process (50% of hormone in each step) by 12 h interval. After the first injection, fish were
retained in the cages in the river beds and 24 hours after the second injection, fish were checked for egg and sperm
release after mild abdomen pressure. Blood samples were taken for determining sex steroid levels. Results showed
that hCG hormone injections caused increase in migration of germinal vesicle in the oocyte of female and sperm
release in males. Significant differences were found in the serum E2 and 17α-OHP levels in hCG - injected fish
compared to the control. However, no significant differences were found in serum T3 and T4 levels in the hCG -
injected fish. According to the results, the appropriate hCG dosage to induce the reproduction acceleration in
Caspian lamprey is 1500-2000 IU.kg BW-1.
Description:
Published
Keywords:
Gonadotropin
;
Maturation
;
Induced reproduction
;
Hormonal changes
;
Caspiomyzon wagneri
;
Chorionic
;
Sexual
;
Sex
;
Steroids
;
Levels
;
Lamprey
Repository Name:
AquaDocs
Type:
Journal Contribution
,
Refereed
Format:
pp.237-247
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