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Comparative gonad histology and semen quality of normal (XY) and neo‐males (XX) of Atlantic salmon ( Salmo salar )
Author(s) -
de Castro Pedro Luiz,
Patil Jawahar G.
Publication year - 2019
Publication title -
aquaculture research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.646
H-Index - 89
eISSN - 1365-2109
pISSN - 1355-557X
DOI - 10.1111/are.14271
Subject(s) - biology , salmo , gonadosomatic index , andrology , broodstock , semen , semen quality , sperm , sexual maturity , spermatogenesis , sertoli cell , gonad , anatomy , endocrinology , medicine , genetics , aquaculture , population , fishery , demography , sociology , fecundity , fish <actinopterygii>
With an overarching objective of improving the hatchery production of Atlantic salmon ( Salmo salar ) all‐female progeny, this study comparatively evaluated the reproductive parameters between normal (genotype XY) and neo‐males (genotype XX). Four normal (XY) and seven neo‐ (XX) males, from the same brood stock, distinguished by their ability to or lack of expressing semen, respectively, were comparatively evaluated. The left testicular lobe was used for histomorphometric analyses, while the right for semen collection and sperm quality analyses. Histomorphometric observations revealed that neo‐male testes are irregularly shaped, and have poorly formed seminiferous ducts, higher proportions of interstitial tissue and lower gonadosomatic index ( p < .05). In addition, hypertrophied and cyst forming Sertoli cells were found in these individuals which collectively appear to form a physical barrier, precluding the semen collection by standard stripping techniques and reducing sperm quality. Particularly, semen motility (80.69 ± 2.4% and 57.2 ± 36.5% for XY and XX respectively) and duration of motility (99.31 ± 28.03 s and 66.84 ± 23.83 s for XY and XX respectively) of neo‐males were most compromised ( p < .05). Interestingly, the TUNEL assay indicated no signs of apoptotic tissue suggesting that the histological differences may relate to delayed physiological/sexual maturity of neo‐males.