Fish fauna in forested and rural streams from an ecoregion of high endemism, lower Iguaçu River basin, Brazil

Abstract

The fish fauna of eight streams with different land uses of their watersheds (forested and rural areas) in the lower Iguaçu River basin was inventoried, in order to evaluate the composition and species richness. The fishes were sampled quarterly from May 2015 to February 2016, using the electrofishing technique. In total, 4,239 individuals were captured, belonging to six orders, 11 families and 26 species. The orders Siluriformes and Characiformes, and the families Characidae and Trichomycteridae were the most specious. Of the total species sampled, 65% were endemic to the Iguaçu River basin, four are not described and four are non-native. As expected to the Iguaçu River basin, the inventoried fauna revealed low richness and high endemism, however was highly nested within the species composition reported for main channel of Iguaçu River and their larger tributaries. The species recorded here corresponded to a subset of 24.5% of the 106 species documented for the basin. The streams presented different faunas, with only two species (Astyanax bifasciatus and Trichomycterus stawiarski) common to both forested and rural streams. In addition, higher species richness was recorded in streams inserted in conservation units. The presence of non-native species was more frequent in rural streams. These results highlight the importance of the preservation of forested areas in the watersheds of lower Iguaçu, which presents a peculiar fish fauna, along with several threats to biodiversity such as habitat loss by intensive agriculture use.

Morphological traits correlated with resource partitioning among small characin fish species coexisting in a Neotropical river

“…The small size and overall body shape allows them to live in any one type of mesohabitat (rapids and backwaters). This design explain the habitat generalism previously observed for these genera (Bertaco, Ferrer, Carvalho, & Malabarba, 2016; Delariva et al, 2018; Kokubun et al, 2018).…”

Ichthyofauna of streams of the Rio Sapucaí basin, upper Rio Paraná system, Minas Gerais, Brazil

“…Ichthyofauna surveys are important for the conservation of freshwater fishes at both short and long-term scales. These studies provide additional information about species' distribution (e.g., Valdiviezo-Rivera et al 2017, Bertora et al 2018, Delariva et al 2018, Honorio & Martins 2018, Oliveira-Silva et al 2018) -which, in turn, may assist in new assessments about their "conservation status" (e.g., Melo et al 2017). Additionally, surveys provide useful data for the establishment of freshwater protected areas (sensu Azevedo- Santos et al 2018a).…”

First record of the non‐nativeXiphophorus hellerii(Cyprinodontiformes: Poeciliidae), in the Iguazu River Basin, Paraná, Brazil

“…Therefore, the introduction of only two individuals of this non‐native species could culminate on the invasion of X. hellerii in all the lower Iguazu River Basin, where there is a highly endemic fish fauna, and vulnerable to non‐native species introduction (Daga et al, ). Native potential predators for this non‐native species in the sampled stream would be the carnivorous species there registered, as Rhamdia branneri Haseman, 1911 (Neves, Delariva, & Wolff, ), and Synbranchus marmoratus Bloch, 1795 (Delariva et al, ; Teresa & Casatti, ).…”