Evidence of perturbations induced by reproduction on somatic growth and microincrement deposition in Oreochromis niloticus otoliths
Abstract:The direct effects of reproduction (energy expenditure for gametogenesis) were studied in gonadectomized Oreochromis niloticus females, incapable of reproducing. The indirect effects of reproduction were studied in intact females that had either mouth brooded their eggs or not. In gonadectomized females the slowing of growth observed in the marginal zone of their otoliths coincided with the time of gonad regeneration. The responses were very varied in the group of intact females. In these females, there was less otolith growth and more checks were observed on the otoliths. The results showed that reproduction influenced the growth of fish and their otoliths leading to a significant underestimate of the number of primary increments during this period of life.
Document Type: Regular Paper
Affiliations: 1: INRAN-Département GRN, B.P. 429, Niamey, Niger, 2: INRA-SCRIBE, Campus de Beaulieu, 35 042 Rennes, France, 3: IRD, B.P. 1386, Dakar, Sénégal, 4: CIRAD-GAMET, B.P. 5095, 34 033 Montpellier Cedex 01, France and 5: Département Halieutique, ENSAR, 65 rue de St-Brieuc, 35 042 Rennes, France
Publication date: 2004-02-01