Distribuição espacial da Tilapia rendalli no Rio Iguaçu (reservatório de Salto Caxias): contribuição para o desenvolvimento da pesca esportiva

Abstract

One of the sports that has grown the most in the last 10 years is sport fishing, and with this, several organizations are encouraging the sport through fishing tournaments. In the Southwest Region of Paraná, the CAPEVI - Vale do Iguaçu Sport Fishing Championship takes place every year - which has as its target fish Tilapia rendalli, a fish species present in the Iguaçu River basin, in the Salto Caxias reservoir where five of the six occur. steps that make up the event. Despite being an exotic species, information about the pattern of displacement and distribution is scarce and necessary for the sustainable exploitation of this resource. During each stage of the tournament, held in the Salto Caxias reservoir, the specimens presented by the competitors were identified, measured and marked with plastic tags, inserted into the muscle tissue in the dorsal region of the fish and then returned to nature. From a total of 520 specimens individually marked and measured before being released in the indicated areas, 86 were captured in the first stage, 215 in the second, 128 in the third stage and 91 animals in the fourth. Among all specimens marked over the 5 months of sampling, only two were recaptured. Through the present study it is possible to affirm that the species T. rendalli has a high population rate in the Iguaçu River basin. The plastic marker can be a viable alternative as an identification method, although it is a methodological adaptation to an imported material that is more expensive and difficult to acquire. However, one of the recaptures also indicated the possibility that the adaptation could present technical problems, such as the detachment of the identification tag from the main plastic rod, making the main purpose of the markings unfeasible. In general, the advances and gaps found in the methodology that based the marking of specimens, may serve as a basis for supporting new studies.