Spar genetic analysis of two invasive species of Cichla introduzidas na Bacia do rio Parana

• Published in: Acta scientiarum. Biological sciences 2011-01, Vol.33 (1), p.79
• Main Authors: Almeida-Ferreira, Giovanna Caputo, de Oliveira, Alessandra Valeria, Prioli, Alberto Jose, Prioli, Sonia Maria Alves Pinto
• Format: Article
• Language: Spanish
• ISSN: 1679-9283
• DOI: 10.4025/actascibiolsci.v33i1.4855

The introduction of exotic species in lake ecosystems has been greatly highlighted in the literature worldwide. Since introduction may threaten diversity of native fish, the issue turns up to be of paramount importance. Ecological effects may be predation, competition, parasitism or genetic, that is, changes in the genetic pool of populations owing to the occurrence of hybrids. Although the Tucunare fish (Cichla) is native to the Amazon region, it can be found in other hydrographic basins in which it has been introduced. RAPD molecular marker research showed that there are two species (Cichla kelberi and C. piquiti) belonging to the genus Cichla in the rivers of the Parana basin. Different morphotypes in the region may also be due to hybridization. Current research used SPAR molecular markers to confirm the presence of hybrids and the rupture of isolation mechanisms. Seventy-two specimens collected in several sites of the river Parana and Amazon basins were analyzed. Since exclusive SPAR molecular markers were obtained for Cichla kelberi and C. piquiti populations, the introduction of the two species in the region has been confirmed. Identification of the markers in specimens of the Parana river basin confirmed hybridization between these exotic species. Key words: hybridization, fish introduction, molecular markers. A introducao de especies exoticas nos ecossistemas lacustres tem sido muito destacada na literatura mundial, pois ameaca a diversidade de peixes nativos, tornando-se uma questao de extrema importancia. Os efeitos observados podem ser ecologicos, como predacao, competicao e parasitismo ou geneticos, como a ocorrencia de hibridos. Apesar do peixe tucunare (Cichla) ser nativo da regiao amazonica, ele pode ser encontrado em outras bacias hidrograficas nas quais foram introduzidos. Estudos utilizando marcadores moleculares RAPD revelaram que existem duas especies (Cichla kelberi e C. piquiti) do genero Cichla na bacia do alto rio Parana e morfotipos diferentes que podem ser devido a hibridizacao. O presente trabalho utilizou marcadores moleculares SPAR para confirmar a presenca de hibridos e os mecanismos de ruptura de isolamento entre essas especies. Setenta e dois especimes foram coletados em diversos pontos da bacia do rio Parana e da bacia Amazonica e foram analisados. Marcadores moleculares SPAR exclusivos foram obtidos para populacoes de Cichla kelberi e C. piquiti, confirmando a introducao das duas especies na regiao. A identificacao dos mar