Genetic monitoring by rapd markers for repopulation programs of Salminus brasiliensis (Pisces, Characiformes) / Monitoramento genético utilizando marcadores RAPD em programas de criação em cativeiro de Dourado

The preservation of the genetic variability of hatchery stocks used to supplement natural populations is a priority. Current study employed RAPD markers to examine the genetic diversity of dourado samples from the middle Paranapanema river and from the broodstock used in the stock enhancement program of the Aquaculture and Hydrobiology Station at the Salto Grande Hydroelectric Power Plant. Nineteen RAPD primers were analyzed, which generated 299 bands and the latter were used for genetic analysis. The percentage of polymorphic fragments was higher in stock captured in the Paranapanema river than from fry stocks. The genetic diversity was lower in the broodstock than in natural population. Amova results showed that most inter-population genetic variation lay within stocks (83.9%) and not between them (16.1%). Moderate genetic differentiation (FST = 0.16) was reported. Nevertheless, differentiation decreased when the four fry stocks were mixed and analyzed as a single population (FST = 0.07). Instead of releasing each lot separately into the water, mixing specimens produced in the various fry stocks before releasing them in the river would be more feasible. The restocked population will have a genetic structure closer to natural populations.

Conservar a variabilidade genética dos estoques de alevinos de peixes para suplementar populações naturais é uma prioridade. O objetivo deste estudo foi examinar a diversidade genética por meio dos marcadores de RAPD de amostras de peixes reprodutores de dourado do médio Paranapanema (população natural) e alevinos usados no programa de repovoamento da estação de aquicultura da UHE de Salto Grande. Foram analisados 19 primers de RAPD, que geraram 299 bandas, as quais foram utilizadas para as análises genéticas. A porcentagem de fragmentos polimórficos foi mais elevada na população natural do que nos estoques. A diversidade genética também foi mais baixa nos alevinos. Os resultados da Amova mostraram que a maior parte de variação genética interpopulacional está dentro dos estoques (83,9%) e não entre eles (16,1%). Foi observada uma diferenciação genética moderada (FST = 0.16). Esta diferenciação diminuiu quando os quatro estoques de alevinos eram misturados e analisados como uma única população (FST = 0.07). Em vez de liberar cada lote separadamente no ambiente, seria melhor misturar todos os indivíduos produzidos nos vários estoques de alevinos antes de liberá-los no rio. Desta maneira, a população reintroduzida terá uma estrutura genética mais perto da população natural.

Genetic monitoring by rapd markers for repopulation programs of Salminus brasiliensis (Pisces, Characiformes) - doi: 10.4025/actascianimsci.v35i2.15904 / Genetic monitoring by rapd markers for repopulation programs of Salminus brasiliensis (Pisces, Characiformes) - doi: 10.4025/actascianimsci.v35i2.15904

The preservation of the genetic variability of hatchery stocks used to supplement natural populations is a priority. Current study employed RAPD markers to examine the genetic diversity of dourado samples from the middle Paranapanema river and from the broodstock used in the stock enhancement program of the Aquaculture and Hydrobiology Station at the Salto Grande Hydroelectric Power Plant. Nineteen RAPD primers were analyzed, which generated 299 bands and the latter were used for genetic analysis. The percentage of polymorphic fragments was higher in stock captured in the Paranapanema river than from fry stocks. The genetic diversity was lower in the broodstock than in natural population. Amova results showed that most inter-population genetic variation lay within stocks (83.9%) and not between them (16.1%). Moderate genetic differentiation (FST = 0.16) was reported. Nevertheless, differentiation decreased when the four fry stocks were mixed and analyzed as a single population (FST = 0.07). Instead of releasing each lot separately into the water, mixing specimens produced in the various fry stocks before releasing them in the river would be more feasible. The restocked population will have a genetic structure closer to natural populations.

The preservation of the genetic variability of hatchery stocks used to supplement naturalpopulations is a priority. Current study employed RAPD markers to examine the genetic diversity of douradosamples from the middle Paranapanema river and from the broodstock used in the stock enhancement programof the Aquaculture and Hydrobiology Station at the Salto Grande Hydroelectric Power Plant. Nineteen RAPDprimers were analyzed, which generated 299 bands and the latter were used for genetic analysis. The percentageof polymorphic fragments was higher in stock captured in the Paranapanema river than from fry stocks. Thegenetic diversity was lower in the broodstock than in natural population. Amova results showed that most interpopulationgenetic variation lay within stocks (83.9%) and not between them (16.1%). Moderate geneticdifferentiation (FST = 0.16) was reported. Nevertheless, differentiation decreased when the four fry stocks weremixed and analyzed as a single population (FST = 0.07). Instead of releasing each lot separately into the water,mixing specimens produced in the various fry stocks before releasing them in the river would be more feasible.The restocked population will have a genetic structure closer to natural populations.

Genetic monitoring by rapd markers for repopulation programs of Salminus brasiliensis (Pisces, Characiformes) / Monitoramento genético utilizando marcadores RAPD em programas de criação em cativeiro de Dourado

The preservation of the genetic variability of hatchery stocks used to supplement natural populations is a priority. Current study employed RAPD markers to examine the genetic diversity of dourado samples from the middle Paranapanema river and from the broodstock used in the stock enhancement program of the Aquaculture and Hydrobiology Station at the Salto Grande Hydroelectric Power Plant. Nineteen RAPD primers were analyzed, which generated 299 bands and the latter were used for genetic analysis. The percentage of polymorphic fragments was higher in stock captured in the Paranapanema river than from fry stocks. The genetic diversity was lower in the broodstock than in natural population. Amova results showed that most inter-population genetic variation lay within stocks (83.9%) and not between them (16.1%). Moderate genetic differentiation (FST = 0.16) was reported. Nevertheless, differentiation decreased when the four fry stocks were mixed and analyzed as a single population (FST = 0.07). Instead of releasing each lot separately into the water, mixing specimens produced in the various fry stocks before releasing them in the river would be more feasible. The restocked population will have a genetic structure closer to natural populations.(AU) 

Conservar a variabilidade genética dos estoques de alevinos de peixes para suplementar populações naturais é uma prioridade. O objetivo deste estudo foi examinar a diversidade genética por meio dos marcadores de RAPD de amostras de peixes reprodutores de dourado do médio Paranapanema (população natural) e alevinos usados no programa de repovoamento da estação de aquicultura da UHE de Salto Grande. Foram analisados 19 primers de RAPD, que geraram 299 bandas, as quais foram utilizadas para as análises genéticas. A porcentagem de fragmentos polimórficos foi mais elevada na população natural do que nos estoques. A diversidade genética também foi mais baixa nos alevinos. Os resultados da Amova mostraram que a maior parte de variação genética interpopulacional está dentro dos estoques (83,9%) e não entre eles (16,1%). Foi observada uma diferenciação genética moderada (FST = 0.16). Esta diferenciação diminuiu quando os quatro estoques de alevinos eram misturados e analisados como uma única população (FST = 0.07). Em vez de liberar cada lote separadamente no ambiente, seria melhor misturar todos os indivíduos produzidos nos vários estoques de alevinos antes de liberá-los no rio. Desta maneira, a população reintroduzida terá uma estrutura genética mais perto da população natural.(AU)

Genetic diversity of the species Leporinus elongatus (Teleostei: Characiformes) in the Canoas Complex - Paranapanema River

Dams constructed along waterways interrupt the dispersion and migration of aquatic organisms, affecting mainly the abundance of migratory fish species. Translocation mechanisms have been constructed at dams aiming to minimize their impact on fish species migration behavior. There is little information available about the effect of the construction of dams on the genetic structure of the Neotropical migratory fish fauna. Therefore, RAPD molecular markers and microsatellites were utilized to evaluate the diversity and genetic structure of the migratory species Leporinus elongatus (piapara) in the Canoas Complex - Paranapanema River - Brazil. Ten groups were sampled in the fish ladders of the hydroelectric dam Canoas I and Canoas II during the reproductive period in three consecutive years. Both markers showed a high level of genetic diversity within these groups. The microsatellite markers demonstrated a loss of heterozygosity and a considerable level of inbreeding in the species. The genetic differentiation found among the groups with both markers utilized is within a range from low to moderate. The data obtained with the parameter of genetic diversity among the groups led to the conclusion that the groups of L. elongatus of the Canoas Complex are structured as a single population composed of sub-populations with low genetic diversity among them. The data on genetic diversity and population structure of L. elongatus are of great importance for the development of the species management and conservation programs in the Canoas Complex, which can also be utilized in aquaculture programs.(AU)

As barragens construídas ao longo de sistemas hídricos interrompem a dispersão e a migração dos organismos aquáticos, afetando principalmente a abundância das espécies de peixes migradores. Mecanismos para transposição foram construídos em barragens visando minimizar esses impactos. Poucas são as informações disponíveis sobre o efeito da construção de barragens na estrutura genética populacional da fauna neotropical de peixes migradores. Nesse contexto, marcadores moleculares RAPD e microssatélites foram utilizados para avaliar a diversidade e a estrutura genética da espécie migradora Leporinus elongatus (piapara) no Complexo Canoas - rio Paranapanema - Brasil. Dez grupos foram amostrados nas escadas para transposição de peixes das UHEs Canoas I e Canoas II durante o período reprodutivo em três anos consecutivos. Ambos os marcadores evidenciaram uma alta diversidade genética para esses grupos. Os marcadores microssatélites mostraram uma perda de heterozigosidade e uma considerável taxa de endocruzamento para a espécie. A diferenciação genética encontrada entre os grupos, com ambos os marcadores utilizados, pode ser considerada de moderada a baixa. Os dados obtidos com os parâmetros de diversidade genética entre os grupos permitiram concluir que os grupos de L. elongatus do Complexo Canoas estão estruturados como uma única população composta por sub-populações com baixa diversidade genética entre elas. Os dados obtidos sobre a diversidade genética e estrutura populacional de L. elongatus são de grande importância para o desenvolvimento de programas de manejo e conservação da espécie no Complexo Canoas, podendo também ser utilizados em programas de aqüicultura.(AU)

Fish passage ladders from Canoas Complex - Paranapanema River: evaluation of genetic structure maintenance of Salminus brasiliensis (Teleostei: Characiformes)

The aim of this study, utilizing RAPD techniques, was to determine the genetic variability of Salminus brasiliensis groups collected at passage ladders of the hydroelectric plants (HEP) Canoas I and Canoas II - Paranapanema River (Brazil), as well as to estimate the population structure through different parameters of genetic diversity. The data obtained allowed us to conclude that S. brasiliensis of the Canoas Complex has a moderate index of genetic variability (P > 42.00 percent) when compared to that of other migratory fish species. All genetic diversity analyses (distance = 0.015 and genetic identity = 0.985, F ST =0.018, AMOVA) were signs of low genetic differentiation, and they led to the clustering of S. brasiliensis from Canoas I and Canoas II. This suggests that the species is genetically structured as a single population. Some findings indicate that this population of S. brasiliensis comes from the Capivara Reservoir (Canoas I downstream), probably fed by the Tibagi and Cinzas Rivers. Literature data denote that after fish transposition by passage ladders of the Canoas Complex, the migratory species are not concluding the reproductive cycle. This mechanism, therefore, could be one more impact factor causing the depletion in downstream recruitment, which could in medium and long term be compromising the natural S. brasiliensis population in the middle Paranapanema River(AU)

O objetivo desse estudo, utilizando a técnica de RAPD, foi estimar a variabilidade genética de grupos de Salminus brasiliensis coletados nas escadas de transposição das hidroelétricas de Canoas I e Canoas II - rio Paranapanema (Brasil), bem como estimar a estrutura populacional através de diferentes parâmetros de diversidade genética. Os dados obtidos permitiram concluir que S. brasiliensis do Complexo Canoas tem um índice moderado de variabilidade genética (P > 42.00 por cento) quando comparado com valores de outras espécies de peixes migradoras. Todas as análises de diversidade genética (distância = 0,015 e identidade genética = 0,985, F ST =0,018, AMOVA) foram indicativas de baixa diferenciação genética, e conduziram ao agrupamento de S. brasiliensis proveniente das escadas de transposição de Canoas I e Canoas II, sugerindo que essa espécie está geneticamente estruturada como uma única população. Alguns dados indicam que essa população de S. brasiliensis é proveniente do Reservatório de Capivara (jusante de Canoas I), provavelmente mantida pelos rios Tibagi e das Cinzas. Dados da literatura indicam que após a transposição das escadas para peixes do Complexo Canoas, as espécies migradoras não estão concluindo o ciclo reprodutivo, esse mecanismo, portanto, pode ser mais um fator de impacto causando a depleção no recrutamento a jusante o que pode a médio e longo prazo comprometer a diversidade genética da população de S. brasiliensis no médio rio Paranapanema(AU)

Genetic monitoring by rapd markers for repopulation programs of Salminus brasiliensis (Pisces, Characiformes) - doi: 10.4025/actascianimsci.v35i2.15904 / Genetic monitoring by rapd markers for repopulation programs of Salminus brasiliensis (Pisces, Characiformes) - doi: 10.4025/actascianimsci.v35i2.15904

The preservation of the genetic variability of hatchery stocks used to supplement natural populations is a priority. Current study employed RAPD markers to examine the genetic diversity of dourado samples from the middle Paranapanema river and from the broodstock used in the stock enhancement program of the Aquaculture and Hydrobiology Station at the Salto Grande Hydroelectric Power Plant. Nineteen RAPD primers were analyzed, which generated 299 bands and the latter were used for genetic analysis. The percentage of polymorphic fragments was higher in stock captured in the Paranapanema river than from fry stocks. The genetic diversity was lower in the broodstock than in natural population. Amova results showed that most inter-population genetic variation lay within stocks (83.9%) and not between them (16.1%). Moderate genetic differentiation (FST = 0.16) was reported. Nevertheless, differentiation decreased when the four fry stocks were mixed and analyzed as a single population (FST = 0.07). Instead of releasing each lot separately into the water, mixing specimens produced in the various fry stocks before releasing them in the river would be more feasible. The restocked population will have a genetic structure closer to natural populations.  

The preservation of the genetic variability of hatchery stocks used to supplement naturalpopulations is a priority. Current study employed RAPD markers to examine the genetic diversity of douradosamples from the middle Paranapanema river and from the broodstock used in the stock enhancement programof the Aquaculture and Hydrobiology Station at the Salto Grande Hydroelectric Power Plant. Nineteen RAPDprimers were analyzed, which generated 299 bands and the latter were used for genetic analysis. The percentageof polymorphic fragments was higher in stock captured in the Paranapanema river than from fry stocks. Thegenetic diversity was lower in the broodstock than in natural population. Amova results showed that most interpopulationgenetic variation lay within stocks (83.9%) and not between them (16.1%). Moderate geneticdifferentiation (FST = 0.16) was reported. Nevertheless, differentiation decreased when the four fry stocks weremixed and analyzed as a single population (FST = 0.07). Instead of releasing each lot separately into the water,mixing specimens produced in the various fry stocks before releasing them in the river would be more feasible.The restocked population will have a genetic structure closer to natural populations.