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End date: 1999 × Start date: 1996 × Thesis Type: M.F.Sc ×
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    ThesisItemOpen Access
    Effect of eyestalk ablation on androgenic gland and male secondary sexual characters in Macrobrachium Idella (Hilgendorf)
    (Department of Aquaculture, College of Fisheries,Panangad, 1998) Sherine Sonia, Cubelio; KAU; Thampy, D M
    The present study in the prawn, Macrobrachium idella was taken up to find out morphotypic variation among the males, the endocrine basis for these variations and also to know the role if any, the eyestalk endocrines have, on the control of androgenic gland, which in turn is controlling the development of male primary and secondary sex characters. The study conducted to find the relationship between development of sex characters with that of androgenic gland conducted using 30 male prawns of different sizes has ShO\\-l1 that these sex characters are under the control of androgenic gland and have no relationship with that of the body size. Of the 30, 22 individuals were found to have a bodylength to cheliped length ratio below 1: 1.5, their androgenic gland and appendix masculina, not fully developed indicating that they are reproductively inactive. Remaining 8 individuals have a body length to cheliped length ratio above I: 1.5. They have well developed androgenic gland and appendix masculina showing that there is positive correlation between the biomass of androgenic gland and the cheliped length. An experiment conducted to find out the effect of unilateral eyestalk ablation on growth and development of primary and seconadry sexual characters as well as on the androgenic gland, had shown that destalking brings about a positive change in the development of androgenic gland and sex characters. The increase in the size of the androgenic gland and consequent hypertrophy of primary and secondary sexual characters brought about as a result of unilateral eyestalk ablation do indicate that the GlH, a hormone produced in the eyestalk has got an inhibitory effect on androgenic gland as well as on the growth of the prawn, which when removed by " destalking" , results in the enlargement of the androgenic gland and other sexual characters.