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Subject: Fish Genetics and Breeding × Author: Yadav, Vinod Kumar × End date: 2004 × Start date: 2004 × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    First maturity and ovarian recrudescence in female Labeo dyocheilus in captivity in tarai region of Uttaranchal
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2004-07) Yadav, Vinod Kumar; Singh, I.J.
    The present study was conducted to assess age for the onset of 1st maturity and gonadal development in female L. dyocheilus and its responses to exogenous hormonal administration for stimulation of ovarian maturity during active reproductive phase. The assessment of age at 1st maturity and ovarian development incorporated macroscopic and microscopic observations of ovary with correlative changes in liver in -1 and +1 year old specimens of L. dyocheilus produced and reared under captivity in Tarai region of Uttaranchal and its correlation with environments changes. The macroscopic parameters used in this work included 1st appearance of gonad, its location, shape, colour etc and indices like GSI, HSI, CF and SCF, while microscopic observations included gross morpho-histophysiolical observations of ovary and associated change in liver in both age groups. Above parameters were also used for evaluating responsiveness of ovary in specimens of both age groups to exogenous hormone i.e. ovaprim. In -1 year old specimen the ovary became visible to naked eye for the first time in March as paired organ at postero-dorsal location in coelomic cavity. The ovary was visible throughout the year in +1 year old specimens. The increasing GSI and correlative decreasing HSI during active reproductive phase, though insignificant, was indicative of their inverse relationship. GSI and ovarian histophysiological changes indicated that after one stage progression to subsequent maturity was not attained. The ovarian development showed a positive correlation with increasing ambient day-length and temperature. The responsiveness of gametic maturity in response to ovaprim better treatment was in twice/week treated group as compared with once/week one and control. It accelerated developmental stages in 1st year age group and terminal maturational events and gonadal development in 2nd year age group. On the basis of these observations it could be inferred that ovaprim has potential use as gametic development and maturity inducing hormone but might need appropriate delivery system for sustained action.