The capture of live bait for sport fishing is an important activity for fishing communities. The main species used for this purpose are members of the genus Gymnotus, which comprises numerous species of cryptic nature that are difficult to identify based on external morphology. The aims of this work were to identify through partial sequences of the COI gene Gymnotus species fished in the Jacaré-Guaçu River, SP, and to develop a molecular diagnostic approach using PCR-RFLP to identify these species. Partial COI sequences were compared to those of other species deposited in GenBank. The sequences were assessed in the NEBCutter program to determine restriction sites in the sequence and the enzymes to be tested. Phenetic analysis performed by Neighbor-Joining method showed that the specimens sampled belong to two species preliminary identified here as G. cf. sylvius and G. cf. cuia, with G. cf. sylvius accounting for 95.2% of the individuals sampled. The enzymes NlaIII and SacI generated fragments that allowed distinguishing the Gymnotus species using PCR-RFLP. This analysis can be used to accurately identify these species, which is fundamental for monitoring Gymnotus fishing and assessing the conservation of this genetic resource.

Introduced species can have strong impacts on the biodiversity, biogeochemistry, and economics of the ecosystems invaded (Darrigran & Damborenea, 2011;Strayer, 2010), as is the case with the golden mussel bivalve Limnoperna fortunei (Dunker, 1857).Monitoring of this species is an important detection tool for determining the level of invasion, reproductive periods and recruitment potential, indicating the most appropriate time for the use of control measures (Boltovskoy et al., 2013;Cataldo & Boltovskoy, 2000;Giglio et al., 2016). In addition, knowledge about its interactions with other organisms allows a greater understanding of population dynamics in relation to the availability of and competition for resources, as well as predation (Rojas Molina et al., 2010). Limnoperna fortunei is an epibenthic bivalve of the familyMytilidae; it is native to freshwater environments and low salinity estuarine regions in Southeast Asia (Ricciardi, 1998). The mollusk was introduced in other continents, probably through ballast water from transoceanic vessels (Darrigran & Damborenea, 2009;

análise qualitativa empregada através de estudo de caso, com emprego de técnicas de entrevistas, mostrou-se adequada na identificação e caracterização da atividade da pesca de isca-viva, avaliando os aspectos socioeconômicos, ambientais, os problemas existentes, os conflitos entre grupos de pescadores com diferentes interesses e anseios da comunidade. Identificou-se para os pescadores isqueiros a necessidade de legalização da pesca de isca-viva com o uso de peneiras. O pescador isqueiro tradicional tem consciência da necessidade de preservação do recurso natural e do ecossistema de forma integrada. No entanto, a sustentabilidade da atividade poderá vir a ser comprometida em curto prazo, caso ocorra à entrada de novos ingressantes na pescaria com interesses puramente econômicos.