Microsatellite analysis of the parental contribution of Piaractus mesopotamicus to the production of offspring in the semi-natural system of reproduction

Abstract

The objective of this study was to evaluate the genetic diversity and the parental contribution of Piaractus mesopotamicus in the production of offspring in the semi-natural system of reproduction. Twenty parental fishes (eleven males and nine females) and the total of 100 larvae were evaluated by microsatellite marker. The parents and offspring had thirty-one alleles and heterozygosity of 0.550 and 0.563, respectively. The females were fertilised by two up to six males while the males fertilised three up to five females. The contribution of the females and males to the offspring were 66.6 and 58%, respectively. Such results indicated no loss in the genetic variability in the offspring, and the parents had multiple paternity and reasonable contribution to the offspring production.

Microsatellite analysis of pacu broodstocks used in the stocking program of Paranapanema River, Brazil

“…This disequilibrium may be due to the number of samples collected. These results are similar to those obtained by Povh et al (2010) where they observed different patterns of linkage disequilibrium in the parental and progeny fishes, without affecting the estimates of genetic diversity.…”

“…The breeding system used in mating (Lopera Povh et al, 2010) and the use of sequential or simultaneous semen during artificial fertilization (Withler and Beacham, 1994) are also factors that may affect the genetic variability of progeny used in stocking programs. Reproductive management is of fundamental importance to preserve the genetic diversity of juveniles which will participate in the stocking programs.…”

Genetic diversity of pacu for restocking programs in the Tietê and Grande rivers, Brazil

“…These results were expected because the broodstocks were formed from the identical ancestral, from the Paraná River (foundation effect), and identical individuals were introduced from the Tietê and Grande rivers. Additional factors, such as the raising system (i.e., a small group of broodstocks, sexual proportions, reproductive dominance, endogamy, high variations among individuals during reproduction) and fluctuation in population size over time, can also be influenced by the homogeneity of current broodstocks (CAMERON-BROWN et al, 2005;BORREL et al, 2007;FOPP-BAYAT et al, 2010;LOPERA-BARRERO et al, 2010b;POVH et al, 2010).…”

“…Although these programs have been performed over several decades, studies of genetic and environmental efficiencies are necessary (AGOSTINHO et al, 2005;POVH et al, 2010). However, many programs have been unsuccessful because of the inappropriate management of broodstocks (BSs) (BORREL et al, 2007;LOPERA-BARRERO, 2009) and the non-monitoring of WPs.…”

“…Only a few studies regarding variability and genetic structure using microsatellites markers have been performed in P. mesopotamicus WPs and BSs (CALCAGNOTTO;DESALLE, 2009;LOPERA-BARRERO et al, 2010a;POVH et al, 2010POVH et al, , 2011. The microsatellite marker is the most used technique to achieve this purpose and has Semina: Ciências Agrárias, Londrina, v. 36, n. 6, p. 3807-3826, nov./dez.…”