Avaliação temporal do processo de introdução da espécie Cichla monoculus (Kullander & Ferreira, 2006) no reservatório de UHE Escola Mackenzie (Capivara) Rio Paranapanema
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Data
2011-07-28
Autores
Casimiro, Armando Cesar Rodrigues [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O Reservatório da UHE Escola Mackenzie (Represa de Capivara) Rio Paranapanema foi constituído em 1977 e representa o maior reservatório em extensão e volume ocupado na bacia hidrográfica do Rio Paranapanema e nas primeiras décadas (80 e 90) após sua formação foi palco de constantes introduções acidentais e intencionais dos mais diversos organismos, sendo uma destas espécies a Cichla monoculus. Neste contexto, diversos pesquisadores concluíram que espécies do gênero Cichla representam importante impacto à bacia do alto Rio Paraná onde foi introduzida, o que originou a presente proposta desse estudo. O objetivo central desse projeto foi realizar uma análise do processo de introdução da espécie Cichla monoculus no reservatório de Capivara, como forma de avaliar biologicamente se a mesma pode ser considerada como uma invasora ―latu senso‖. Foram compilados dados de captura dos anos de 1991 a 1999 (relativos ao projeto Tibagi, trecho reservatório). E as coletas relativas a este estudo foram realizadas trimestralmente correspondendo ao período de outono de 2001 a verão de 2002, outono de 2002 a verão de 2003 e outono de 2009 a verão de 2010 finalizando 3 ciclos (I, II e III, respectivamente). Os resultados nos possibilitaram verificar que após 3 anos da primeira introdução da espécie (1997 a 1998), a mesma já alcançou proporções de abundancia equivalente as nativas e com acréscimo populacional subseqüente até 2003, com forte indicativo de um processo de estabelecimento e conseqüente invasão no reservatório, com modesta depleção durante o ultimo ciclo de estudo (Ciclo III). Os dados de densidade (CPUEn) demonstram uma tendência ao decréscimo e o comprimento padrão médio não apresentou alterações significativas. A proporção sexual apresentou grande...
The UHE Escola Mackenzie (Capivara Reservoir) Paranapanema River, was build in 1977 and nowadays is de biggest reservoir in extension and volume in the Paranapanema River Basin. In the first two decades after your construction occurred several introduction (accidental or on purpose) of none native fishes in this area. One of this species was Cichla monoculus. In this context, several researches concluded that species belonging to the Cichla gender cause important impact to the Parana River Basin where it has been introduced. The idea of this project came from these observations. The aim of this study was to analyze the introduction process of the species Cichla monoculus in the Capivara reservoir and to evaluate biologically if this species is established or not in the reservoir. Data from an old project realized in the same area was used covering a period from 1991 to 1999 (Tibagi Project). The samples related to this study were spread in three different cycles (I, II and III): autumn 2001 to summer 2002, autumn 2002 to summer 2003 and autumn 2009 to summer 2010, respectively. The data shown that three years after the C. monoculus accidental escaping the species reach abundance proportions equivalent to de native species and further increase to 2003, indicating a establishment process and consequent invasion of the reservoir system, with small depletion during the last cycle (Cycle III). The CPUEn shown a decrease tendencies and the standard length did not present significant alterations. The sexual proportion presents variations and was attributed to the environmental factors. During the study, juveniles were sampled mainly (86.98% Cycle I; 81.81% Cycle II e 83.84% Cycle III) indicating a recruitment success. More than 55% of the specimens collected were between 6 to 11 centimeters of standard... (Complete abstract click electronic access below)
The UHE Escola Mackenzie (Capivara Reservoir) Paranapanema River, was build in 1977 and nowadays is de biggest reservoir in extension and volume in the Paranapanema River Basin. In the first two decades after your construction occurred several introduction (accidental or on purpose) of none native fishes in this area. One of this species was Cichla monoculus. In this context, several researches concluded that species belonging to the Cichla gender cause important impact to the Parana River Basin where it has been introduced. The idea of this project came from these observations. The aim of this study was to analyze the introduction process of the species Cichla monoculus in the Capivara reservoir and to evaluate biologically if this species is established or not in the reservoir. Data from an old project realized in the same area was used covering a period from 1991 to 1999 (Tibagi Project). The samples related to this study were spread in three different cycles (I, II and III): autumn 2001 to summer 2002, autumn 2002 to summer 2003 and autumn 2009 to summer 2010, respectively. The data shown that three years after the C. monoculus accidental escaping the species reach abundance proportions equivalent to de native species and further increase to 2003, indicating a establishment process and consequent invasion of the reservoir system, with small depletion during the last cycle (Cycle III). The CPUEn shown a decrease tendencies and the standard length did not present significant alterations. The sexual proportion presents variations and was attributed to the environmental factors. During the study, juveniles were sampled mainly (86.98% Cycle I; 81.81% Cycle II e 83.84% Cycle III) indicating a recruitment success. More than 55% of the specimens collected were between 6 to 11 centimeters of standard... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Paranapanema, Rio - Biologia, Peixe - Ecologia, Biological invasion, Cichla monoculus
Como citar
CASIMIRO, Armando Cesar Rodrigues. Avaliação temporal do processo de introdução da espécie Cichla monoculus (Kullander & Ferreira, 2006) no reservatório de UHE Escola Mackenzie (Capivara) Rio Paranapanema. 2011. 29 f. Dissertação (mestrado) - Universidade Estadual Paulista, Instituto de Biociências de Botucatu, 2011.