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Ovarian development and related changes in steroid hormones in female wild common carp ( C yprinus carpio carpio ), from the south‐eastern C aspian S ea
Author(s) -
Vazirzadeh A.,
Mojazi Amiri B.,
Fostier A.
Publication year - 2014
Publication title -
journal of animal physiology and animal nutrition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.651
H-Index - 56
eISSN - 1439-0396
pISSN - 0931-2439
DOI - 10.1111/jpn.12171
Subject(s) - gonadosomatic index , biology , vitellogenesis , reproduction , testosterone (patch) , development of the gonads , hormone , cyprinus , carp , common carp , seasonal breeder , medicine , endocrinology , zoology , oocyte , gonad , fishery , fish <actinopterygii> , ecology , population , embryo , fecundity , environmental health
Summary Wild common carp ( C yprinus carpio carpio ) is a native valuable but threatened species from the south‐eastern Caspian Sea in which the endocrine control of its reproduction has not been studied. The objectives of this research were to study the reproductive strategy and changes in steroid hormones during ovarian development. From October 2009 to June 2010, 65 adult females were caught from the Golestan coast (Iran) and the ovarian histology, and gonadosomatic and hepatosomatic indices ( GSI and HSI ) were studied. Also, the plasma profiles of steroid hormones including testosterone (T), 17 β ‐estradiol (E2) and 17 α‐ , 20 β ‐dihydroxyprogesterone ( DHP ) were measured by radioimmunoassay. The GSI increased gradually during sampling times and reached maximum value at the peak of reproduction season, but the HSI decreased during spawning season. All stages of ovarian development, except the stage of Balbiani bodies, were recorded macro‐ and microscopically. Spent fish were caught at six of nine sampling times. The peaks of spawning were at late winter and early spring. The results of this study showed that the majority of wild carp collected during the sampling period displayed asynchronous oocyte development. Plasma T showed no significant differences during sampling times or at different stages of ovarian development. The level of E2 decreased gradually during sampling times reached minimum value at the spawning season, and highest value was recorded at tertiary vitellogenesis stage. The plasma levels of DHP during late winter and early spring were significantly higher than those of other sampling periods and its maximum level associated with oocyte maturation stage.