Environmental Biology of Fishes

, Volume 52, Issue 4, pp 453–465

Variations in age and size at maturity of female Nile tilapia, Oreochromis niloticus, populations from man-made lakes of Côte d'Ivoire

  • Fabrice Duponchelle
  • Jacques Panfili

DOI: 10.1023/A:1007453731509

Cite this article as:
Duponchelle, F. & Panfili, J. Environmental Biology of Fishes (1998) 52: 453. doi:10.1023/A:1007453731509


The reproductive characteristics of Oreochromis niloticus females were studied in two large hydroelectric dams and 6 small agropastoral reservoirs of Côte d'Ivoire, selected for their diversity of environmental conditions and sizes (6 to 80000 ha). Comparative analysis of age and size at maturity revealed large differences between the populations with early maturity, late maturity, and intermediate situations. All the populations matured in their first year, between 5.6 and 10 months. Age and size at maturity were positively correlated with the reservoir area. The range of variation in age at maturity between populations was far greater than that of size at maturity. However, size at maturity also appears to be very plastic as intra-population variations of 2 to 3 cm were found between consecutive years. A comparison of age at maturity for a population in 1994 and 1996 showed that this trait is also likely to vary significantly at the intra-population level. Environmental factors which could potentially affect age and size at maturity are discussed. Growth differences are the probable explanation for the observed patterns of variation between populations. Rapid changes in age and size at maturity at inter or intra-population levels suggest that the observed variations might be explained by differences in environmental variables (phenotypic plasticity) rather than by genetic differences.

phenotypic plasticity reproductive style fish cichlid 

Copyright information

© Kluwer Academic Publishers 1998

Authors and Affiliations

  • Fabrice Duponchelle
    • 1
  • Jacques Panfili
    • 2
  1. 1.Orstom, GametMontpellier Cedex 1France
  2. 2.Orstom, LasaaPlouzanéFrance