Development of Heat-Shocked Tilapia Eggs Following Activation by Water Immersion or Heterologous Fertilization: Implications for the Initiation of Gynogenesis

Abstract

An attempt was made in this study to initiate artificial gynogenesis in tilapia eggs by water activation, as an alternative to heterologous fertilization. Blue tilapia Oreochromis aureus (Steindachner) eggs activated by water immersion and heat-shocked at 42 oC failed to develop into gynogens. However, heat shock of eggs fertilized with normal or irradiated carp sperm developed into putative gynogens. Un-shocked normal or irradiated carp-fertilized eggs died shortly after hatching due to haploid condition or hybrid inviability. Results of this study indicate that, sperm contact is necessary for successful initiation of gynogenesis.

Journal of the Ghana Science Association Vol. 9 (2) 2007: pp. 32-37