Inventory of the fish fauna from Ivaí River basin, Paraná State, Brazil

Abstract

Abstract:We compiled data on fish fauna of the Ivaí River basin from recent specialised literature, standardised sampling and records of species deposited in fish collections. There were 118 fish species of eight orders and 29 families. Of these, 100 species are autochthonous (84.8%), 13, allochthonous (11.0%) and five, exotic (4.2%). The main causes for the occurrence of non-native species are escapes from aquaculture, introduction for fishing purposes and the construction of the Itaipu hydroelectric plant. The predominance of small and medium-sized Characiformes and Siluriformes, including 13 species new to science, accounts for approximately 11.0% of all species and 13.0% of all native species. About 10.2% of all species and 12.0% of all native species are endemic to the upper stretch of the Ivaí River, isolated by numerous waterfalls in tributary rivers and streams. The Ivaí River basin is subjected to various anthropogenic interferences such as pollution, eutrophication, siltation, construction of dams, flood control, fisheries, species introduction and release of fingerlings. These activities raise concerns about biodiversity of Brazilian inland waters especially regarding the fish fauna; the basin of the Ivaí River already has species classified in categories of extinction risk: Brycon nattereri and Apareiodon vladii (Vulnerable) and Characidium heirmostigmata and Steindachneridion scriptum (Endangered). The high species richness of native fish, endemism of some, high environmental heterogeneity, high risk of extinction and lack of knowledge of several other species along with the eminent human activities raise the need to enrich the scientific knowledge for future conservation efforts for the studied basin. Resumo: Nós compilamos dados sobre a diversidade da ictiofauna da bacia do rio Ivaí proveniente de recentes informações contidas em estudos divulgados na literatura especializada, coletas padronizadas e registros das espécies depositadas em coleções ictiológicas. Foram registradas 118 espécies de peixes pertencentes a oito ordens e 29 famílias. Dessas, 100 são autóctones, (84.8%), 13 são alóctones (11.0%) e cinco são exóticas (4.2%). As principais causas da ocorrência de espécies não nativas são escapes da piscicultura, introduções para pesca e a construção da usina hidrelétrica de Itaipu. Ocorre o predomínio de espécies de Characiformes e Siluriformes com porte pequeno e médio, sendo que 13 espécies são novas, o que representa aproximadamente 11.0% do total de espécies e 13.0% do total de espécies nativas. Ainda, aproximadamente 10.2% do total de espécies e 12.0% do total de espécies nativas correspondem a espécies endêmicas, isoladas pela presença de inúmeras cachoeiras em rios e riachos afluentes no trecho superior do rio Ivaí. A bacia do rio Ivaí está sujeita a uma variedade de interferências antrópicas como poluição, eutrofização, assoreamento, construção de represas, controle do regime de cheias, pesca, introduções de espécies e soltura de alevinos. Tais atividades apontam alarmantes preocupaçõe...

Update on the ichthyofauna of the Piquiri River basin, Paraná, Brazil: a conservation priority area

“…This new update represents a nearly 120% increase in the number of species recorded in the basin since the last list was released. When comparing the ichthyofauna found in the basins located in the State of Paraná, the Piquiri River basin has an absolute richness of fish species that is higher than the richness of the Pirapó basin (76 species, Pagotto et al 2012), the Ivaí River basin (118 species, Frota et al 2016a), the upper and lower Iguaçu River basin (41 and 106 species respectively, Ingenito et al 2004, and the Tibagi River basin (151 species, Raio & Bennemann 2010). Approximately 49% of the species listed here were coincident with those recorded for the upper Paraná River (see Langeani et al 2007).…”

“…are shared, respectively, with the basins of the Jordão (lower Iguaçu River) and Ivaí (upper Paraná River) Rivers. The former species is reported as endemic to the Iguaçu River basin , while the latter is regarded as endemic to the upper Ivaí River basin (Frota et al 2016a). Therefore, the presence of these species in the Piquiri River basin suggests past connections between the upper courses of those basins that might have occurred prior to the uplift of Serra da Esperança, which caused the isolation of the respective headwaters (Frota et al 2016b).…”

“…In addition, the species were categorized by origin based on the Langeani et al (2007) method and grouped into autochthonous (native to the upper Paraná River basin), allochthonous (introduced species belonging to the Neotropical region), and exotic (from other continents) categories. If introduced, the introduction vectors were determined based on the species occurrence and distribution, as well as relevant literature, according to Reis et al (2003), Langeani et al (2007), Graça & Pavanelli (2007), Júlio Jr. et al (2009 and Frota et al (2016a). The possible causes of the occurrence of these species in the Piquiri River basin were grouped into seven categories: 1) Itaipu, species first recorded shortly after the construction of the Itaipu Dam with its native populations from the lower Paraná River basin; 2) Itaipu channel, species also coming from the lower Paraná River basin and introduced as a result of the construction and operation of the Itaipu Piracema Channel; 3) aquaculture, species widely used in the fish farms in the region; 4) baiting, species introduced by the use of natural baits for sport fishing; 5) mosquito control and aquarium purposes, species introduced for mosquito population control and species highly represented in fishkeeping; 6) sport-fishing, species introduced for sport fishing; 7) stocking, species introduced for fish stocks.…”

“…Spatial and temporal fish assemblage patterns can be understood by biotic, abiotic and spatial factors that determine fish assemblage biodiversity (Jackson et al 2001), enabling the assessment of the environmental quality of a river system. Although much sampling has been carried out in basins to record existing ichthyofaunal compositions, several species are still unknown by science (Langeani et al 2007, Galves et al 2009, Frota et al 2016a. Recent fish inventories in previously sampled areas have revealed new species (Pavanelli 2006, Frota et al 2016a; consequently, the number of descriptions of new species has increased in recent years.…”

“…Although much sampling has been carried out in basins to record existing ichthyofaunal compositions, several species are still unknown by science (Langeani et al 2007, Galves et al 2009, Frota et al 2016a. Recent fish inventories in previously sampled areas have revealed new species (Pavanelli 2006, Frota et al 2016a; consequently, the number of descriptions of new species has increased in recent years. It is thought that a full description of existing species is still far from being achieved (Ota et al 2015).…”