Importance of the Congonhas River for the conservation of the fish fauna of the Upper Paraná basin, Brazil

Abstract

Abstract. Garcia DAZ, Vidotto-Magnoni AP, Costa ADA, Casimiro ACR, Jarduli LR, Ferraz JD, De Almeida FS, Orsi ML. 2019. Importance of the Congonhas River for the conservation of the fish fauna of the Upper Paraná basin, Brazil. Biodiversitas 20: 474-481. The Upper Paraná River basin is among the most fragmented watersheds in the world. The Congonhas River belongs to this drainage system, which has its mouth in the Capivara Reservoir and can be considered the largest tributary free-from-dam, becoming important for the maintenance of fish species richness. In order to know more about the species present in this tributary, we aimed to provide an inventory of fish fauna of the Congonhas River and reproductive strategies to determine whether the river is used by migratory species and whether there is a longitudinal variation in the fish assembly. These findings will provide subsidies to contribute to the implementation of policies to protect biodiversity. Samplings occurred in the upper, middle and lower stretches of the Congonhas River during four periods between 1991 and 2011. Fishes were captured using gill nets from 2 to 14 cm mesh sizes between opposite knots and cast nets, identified and categorized according to their reproductive strategies. A total of 4,640 individuals belonging to 63 species, of which 79.4% consisted of Characiformes and Siluriformes were captured. Furthermore, 14% of fish were long-distance migratory species (e.g., Piaractus mesopotamicus, Megaleporinus obtusidens, Prochilodus lineatus, Salminus brasiliensis, Pinirampus pirinampu, and Pseudoplatystoma corruscans). In addition, there was an increase in the fish species richness from upstream to downstream. Management actions such as prohibition of fishing, rehabilitation of riparian vegetation, and protection of the basin against dam construction will reduce anthropogenic impacts on the ecosystem. The Congonhas River highlights the importance of preserving lotic environmental for the conservation of migratory and non-migratory Neotropical fish diversity into a heavily modified watershed.

Use of DNA barcode in the identification of fish eggs in tributaries of the Paranapanema River basin

“…For the Congonhas River, a tributary of the Tibagi River, only one species was found, Triportheus nematurus. However, this result is probably due to the small number of sampled eggs collected at this point, since this tributary still maintains adequate conditions that favor the conservation of fish including native and migratory species (Garcia et al, 2019).…”

Fish defaunation in reservoirs of the Lower Paranapanema River basin, Brazil

“…Marques et al (2018) recorded 79 species in Porto Primavera Reservoir, a large reservoir with a length of 270 km in the Paraná River mainstem. They reported the importance of riverside stretches upstream of the reservoir, and Garcia et al (2019) recorded 63 species in a stretch of 110 km in the Congonhas River, which has lotic features and directly flows into reservoirs. In the Neotropical region, the fragmentation and the simplification of habitats promoted by reservoirs is the main human interference in natural hydrological regimes (Agostinho et al 2007a).…”

“…It is important to emphasize that the decrease in populations of migratory species due to the interruption of their routes by dams has been widely recorded throughout the Upper Paraná River basin (Agostinho et al 2002, Pelicice et al 2014, Marques et al 2018, although our results did not detect high levels of defaunation for the migratory functional group. Nonmigrators had higher defaunation rates than did migrators, the negative pressure exerted on migratory populations is higher in a succession of cascading reservoirs, and it is in tributaries without dams that they seek favorable environmental conditions for reproduction (Agostinho et al 2004, Pelicice et al 2014, Garcia et al 2019.…”

Etnoecologia de pescadores artesanais sobre espécies nativas e exóticas em reservatórios do semiárido brasileiro

“…Provavelmente, por se tratar de uma espécie exótica (Froese & Pauly, 2021) e que vive em águas profundas (Goulding, 1980), a resposta dos pescadores indicou que estes não conhecem muito a respeito do local de desova da pescada. Todavia, há de se considerar ainda que se trata de uma espécie de grande porte que alcança tamanho máximo superior a cinquenta centímetros (Camargo & Lima-Júnior, 2008) (Garcia et al, 2019;Winemiller, 2001). Os pescadores justificaram sua resposta com base na agressividade destes peixes, que, por este motivo, não cuidavam de seus filhotes.…”

“…Para a pescada (P. squamosissimus), a análise de frequência foi de 6,74% de respostas, na Ilha de Esaú, em acordo com a literatura científica, que afirma que esta espécie não possui cuidado parental (Garcia et al, 2019). O baixo percentual desta análise ocorreu porque em torno de 45% dos pescadores desta comunidade não souberam responder sobre a existência ou não de cuidado parental nesta espécie.…”