Selecting areas with rare and restricted fish species in mountain streams of Southern Brazil

Abstract

The delimitation of conservation units may be supported by information on compositional (taxonomic), functional, and phylogenetic diversity of a given locality or region. In this context, systematic conservation planning and key biodiversity areas are promising approaches for biodiversity protection. Factors such as species representativeness and exclusivity may be used to identify geographical distribution patterns and select relevant areas for conservation at a local scale. This study aims to identify areas with rare and restricted fish species in mountain streams in Southern Brazil, using a method that unites ecological and biogeographical approaches. Seven river basins and 152 mountain streams in Southern Brazil were sampled to obtain data on the occurrence and abundance of 115 fish species. The rarity status of each species was determined and endemicity analysis was used to find areas of restricted species (ARS) with three cell sizes. Using larger cells, continuous areas were identified and supported by a higher proportion of rare fish species. Using smaller cells, discontinuous areas were identified within each of the river basins, where rare and endemic fish species occur. Most of the smaller areas relevant for protecting fish fauna were located outside of conservation units. Fundamental areas were selected for the protection of fish species in mountain streams in Southern Brazil. Both the method proposed and the areas with rare and restricted fish species identified may be used to support systematic conservation planning and to delimit new priority areas for conservation.

Spatial distribution patterns and predictors of fish beta‐diversity in a large dam‐free tributary from a Neotropical floodplain

“…Besides, isolated fish populations in headwaters are expected to be highly structured genetically (Thomaz et al, 2016). Over time, this process may have limited fish species distribution and caused local speciation (Carvajal‐Quintero et al, 2019) in mountains streams from the upper Ivaí River basin (Frota, Pacifico, & Graça, 2021).…”

“…Over time, this process may have limited fish species distribution and caused local speciation (Carvajal-Quintero et al, 2019) in mountains streams from the upper Ivaí River basin (Frota, Pacifico, & Graça, 2021).…”

“…Efforts to increase the sampling of the fish fauna from the Ivaí River basin (Reis, Frota, Deprá, et al, 2020) resulted in the discovery of several new endemic taxa (Dias & Zawadzki, 2021; Graça & Pavanelli, 2008; Reis, Frota, Fabrin, & Graça, 2020; Roxo et al, 2014; Tencatt et al, 2014; Zawadzki et al, 2016). An updated checklist including 108 native and 24 non‐native species (Reis, Frota, Deprá, et al, 2020), as well as distribution patterns of rare and restricted species in some mountain streams (Frota, Pacifico, & Graça, 2021), and growth parameters for endemic species (Frota, Ganassin, & Graça, 2021) have been recently described. In Paraná State, all remaining sub‐ecoregions of the upper Paraná ecoregion have a lower rate of endemism if compared to the Ivaí River basin.…”

“…With a predominance of narrow rocky valleys and rapids across its upper and middle courses, the Ivaí River is one of the largest dam-free tributaries of the upper Paraná River floodplain (East margin) and stands out by its largely intact hydrologic dynamics. Besides affording refuge to the ichthyofauna of that floodplain (Affonso et al, 2015), the Ivaí River basin also harbours rare and endemic fish species, several of which occur outside the limits of the conservation units (see Frota, Pacifico, & Graça, 2021). Actually, there is a huge gap for effective legal protection of the Ivaí River basin's aquatic biota.…”

“…Efforts to increase the sampling of the fish fauna from the Ivaí River basin (Reis, Frota, Deprá, et al, 2020) resulted in the discovery of several new endemic taxa (Dias & Zawadzki, 2021;Graça & Pavanelli, 2008;Reis, Frota, Fabrin, & Graça, 2020;Roxo et al, 2014;Tencatt et al, 2014;Zawadzki et al, 2016). An updated checklist including 108 native and 24 non-native species (Reis, Frota, Deprá, et al, 2020), as well as distribution patterns of rare and restricted species in some mountain streams (Frota, Pacifico, & Graça, 2021), and growth parameters for endemic species (Frota, Ganassin, & Graça, 2021) 53 41 0 43 00 W) and runs through a wide range of landscapes that are distinct in lithology (Leli et al, 2017;Meurer et al, 2010;Souza et al, 2018). It includes five large ecoregions (each divided into two sub-ecoregions) distinct in geomorphology, pedology, vegetation, topography, climate and precipitation (Meurer et al, 2010), providing a reasonable basis for the delimitation of its upper, middle and lower sections by Leli et al (2017).…”