| Full text | |
| Author(s): |
Total Authors: 5
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| Affiliation: | [1] Univ Sao Paulo, Inst Biosci, BR-05508900 Sao Paulo - Brazil
[2] Univ Sao Paulo, Inst Biomed Sci, BR-05508900 Sao Paulo - Brazil
[3] APTA, Inst Fisheries, BR-05001900 Sao Paulo - Brazil
Total Affiliations: 3
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| Document type: | Journal article |
| Source: | FISH PHYSIOLOGY AND BIOCHEMISTRY; v. 35, n. 1, p. 109-123, MAR 2009. |
| Web of Science Citations: | 27 |
| Abstract | |
Fecundity and oocyte development in Salminus hilarii female brood stock were analyzed with the aim of investigating the impact of migration impediment on oogenesis. Histological analyses of the ovaries were performed in adult females caught in two different environments-the TietA(a) River (natural) and captivity-and the gonadossomatic index, oocyte diameter and fecundity determined. Five germ cell development stages (oogonium, perinucleolar, cortical alveoli, vitellogenic, ripe) and two other structures (postovulatory follicles and atretic oocytes) were observed in females caught in the river. Captive animals lacked the ripe oocytes and postovulatory follicles and had a relatively higher number of atretic oocytes. Females in captivity are known to produce larger oocytes, and they release fewer eggs in each spawn (absolute fecundity) when compared with animals that are able to migrate. Our results suggest that the TietA(a) River is undergoing alterations which are being reflected in the reproductive performance of S. hilarii, mainly due to the presence of atretic oocytes in females caught in the river. The lack of postovulatory follicles and ripe oocytes in captive animals reveals that migratory impediment negatively impacts final oocyte maturation. However, the stage of maturation reached is adequate for ovulation induction with hormone manipulation. (AU) | |