Diversidade genética de pacu do Rio Paranapanema e do estoque de um programa de repovoamento

Abstract

Resumo -O objetivo deste trabalho foi estudar a diversidade genética das amostras de pacu do médio Rio Paranapanema e do estoque de reprodutores utilizado no programa de repovoamento da Estação de Aqüicultura e Hidrologia da usina hidrelétrica Duke Energy, por meio do marcador RAPD. Genetic diversity of pacu from the Paranapanema River and from the broodstock of a stock enhancement programAbstract -The objective of this work was to study the genetic diversity of pacu samples from the middle Paranapanema River and from the broodstock used in the stock enhancement program of the Aquaculture and Hydrology Station at the Duke Energy Power Plant, by RAPD marker. Fourteen primers were used to analyze 30 individuals captured in the middle Paranapanema River and 29 individuals from the broodstock. The Shannon genetic diversity index and percentage of polymorphic fragments were higher in individuals captured in the Paranapanema River. Genetic similarity was larger in individuals of the broodstock. Results of analysis of molecular variance showed that the major part of the genetic variation is within the groups (84.2%) and not between them (15.8%). The identity and genetic distance among the groups were 0.9517 and 0.0549, respectively. Moderate genetic differentiation (F ST = 0.15) and high number of migrants per generation (Nm = 5.33) were observed between the two groups. The genetic diversity was lower in the broodstock than in fish captured in the middle Paranapanema River.

Population genetic structuring in pacu (Piaractus mesopotamicus) across the Paraná-Paraguay basin: evidence from microsatellites

“…The authors, however, recognize that the fact of releasing hatchery reared immature fish inside the reservoir could have influenced the results. Povh et al (2008) using RAPD markers detected moderate population differentiation between 29 pacu from the broodstock of the Estação de Aquicultura e Hidrobiologia of the Duke Energy power plant (formed by 250 fish from rio Paraná) and 30 pacu captured on the fish ladders of the Canoas I and II reservoirs located in the mid rio Paranapanema. On the other hand, in the upper rio Paraná, in a region that is free of dams, Revaldares et al (1997) analysed 19 isozymes in Prochilodus lineatus from the rios Paraná, Ivinheima and Baia and although the authors detected high polymorphims and heterozygosity the Nei's values for genetic similarity were also high indicating that they form a panmitic population.…”

“…Most population studies on Neotropical fish species seem to point out to some level of population structuring (Hatanaka & Galetti Jr., 2003;Barroso et al, 2005;Povh et al, 2008). Sanches & Galetti Jr. (2007) used RAPDs to assess the genetic variability of 80 individuals of the migratory characin Brycon hilarii at four sites of the rio Miranda subbasin (Paraná-Paraguay basin) and found significant population differences.…”

“…Despite of its great economic importance, there is only very limited information about the migration patterns of this species (Agostinho et al, 2003;Resende, 2003, and references therein) and there is only one published study on the population structure of pacu (Povh et al, 2008). To the best of our knowledge our study is one of the very few to use microsatellite markers to assess fish population structure in the Neotropical region and the first to employ this technique on an economically important fish in the Paraná/Paraguay basin.…”

Genetic characteristics of Tambaqui broodstocks in the state of Rondônia, Brazil: implications on production and conservation

“…Similar results were reported by Lopera-Barrero et al (2008b) in Brycon orbignyanus broodstocks where an offspring with six excluded fragments was reported, or rather, loss of genetic variability when compared with broodstock, but with high intrapopulation genetic variability. Povh et al (2008) also reported four excluded fragments in Piaractus mesopotamicus broodstocks, or rather, a lower genetic variability when compared with natural population. However, the intra-population genetic characterization was high.…”

Genetic diversity of Salminus brasiliensis wild populations in downstream and upstream Cachoeira Branca, Verde River MS Brazil: a preliminary view

“…Dominant marker in current assay proved efficient in the study of genetic variability. Other studies with the same marker for S. brasiliensis (ALMEIDA et al, 2013;GOMES et al, 2011GOMES et al, , 2013LOPES et al, 2007) and in other fish species (JACOMETO et al, 2010;, 2010LOPES et al, 2009;PAULA et al, 2006;POVH et al, 2008b) also gave positive results. In fact, dominant markers still have great possibilities of information for the initial review of genetic processes in natural populations or in fish stocks.…”