Variability in the production of larvae of Prochilodus magdalenae used in restocking programs in the Magdalena River, Colombia

The objective of this research was to evaluate the effect of individual genetic variability of spawners in the procurement (production and genetic quality) of Prochilodus magdalenae larvae, used in the repopulation programs in the Magdalena river (Colombia). The spawners system was used based on the genetic criteria of the Centro Acuicola y Agroindustrial de Gaira (SENA Magdalena, Colombia), forming groups with different levels of individual heterozygosity (Ho<=0.3; 0.3>Ho<=0.6 y Ho>0.6). The hormonal induction was done with Pituitary Carp Extract (PCE) using a dosage of 6.6 mg/Kg. The production parameters in the different levels of heterozygosity were measured, such as weight, fertility, fertilization rate, hatching and survival rate. The larvae obtained were fixed in alcohol at 96% for the genetic analyses performed through the use of seven loci micro-satellites. There were significant differences between the individual heterozygosity intervals both in the production parameters and in the genetic quality of the obtained progenies (p < 0.05). A decrease was detected in the heterozygosity observed in the obtained progenies (Ho=0.198, 0.203, 0.392) compared to the heterozygosity of the spawners (Ho=0.190, 0.444, 0.730) for the three intervals of heterozygosity evaluated. The parameters of weight production, fertilization rate and survival, as well as the genetic quality in terms of Ho and Fis of the obtained progenies, are positively related with the genetic variability of the spawners. It is therefore advised that in order to implement breeding programs, spawners with individual heterozygosity values above 0.6 are used for the production of larvae destined to the repopulation of natural communities of P. magdalenae.