Genetic analysis of five sedentary fish species in middle Laranjinha River (upper Paraná River basin): A case study

Abstract

ABSTRACT. Most studies of diversity and genetic structure in neotropical fish have focused on commercial species from large rivers or their reservoirs. However, smaller tributaries have been identified as an important alternative migratory route, with independent pools of genetic diversity. In this context, the present study aimed to evaluate genetic diversity and structure in five neotropical fish species from a region of Laranjinha River in the upper Paraná River basin. PCR-RAPD (random amplified polymorphic DNA) markers were used to characterize around 40 individuals of each species distributed upstream and downstream of Corredeira Dam that interrupts the river. The descriptive index of genetic diversity (P = 30.5-82%; H E 0.122-0.312) showed that the populations have acceptable levels of genetic diversity. The values for Nei's genetic distance (D N min 0.0110 and max 0.0306) as well as the genetic structure index and the analysis of molecular variance (AMOVA, ϕ ST min 0.0132 and max 0.0385) demonstrated low, but significant levels of genetic structure. Bayesian analysis of assignment found two k clusters, including several individuals with mixed ancestry for all populations from the five species analyzed. These findings along with historical data on rainfall and the low dimensions of the dam studied here support the hypothesis that periodic floods enable the transit of individuals between different localities mitigating the differentiation process between populations.

Inventory of the fish fauna from Laranjinha River, Paranapanema River system, Brazil

“…Such results follow the pattern found in the Neotropical regions, showing the dominance of Siluriformes and Characiformes (Agostinho et al 1997, Lowe-McConnell 1999, Jarduli et al 2020. Furthermore, among Paranapanema River tributaries, the number of species is lower if compared to the Tibagi River basin, where 158 species were registered (Lobón-Cerviá & Bennemann 2000, Bennemann et al 2006, 2011, Shibatta & Cheida 2003, Hoffmann et al 2005, Oliveira & Bennemann et al 2005, Jerep et al 2006, Sant'Anna et al 2006, Shibatta et al 2002, 2006a, 2006b, Galves et al 2007, Vieira & Shibatta 2007, Orsi 2010, Raio & Bennemann 2010, Garcia et al 2014, Frantine-Silva et al 2015, Almeida et al 2018, Jerep & Shibatta 2017, Claro-Garcia et al 2018, and to the Cinzas River, with 114 species (Hoffmann et al 2005, Vianna & Nogueira, 2008, Orsi 2010, Bennemann et al 2011, Costa et al 2013, Frantine-Silva et al 2015, Almeida et al 2018.…”

“…Fish inventories were carried out in the Paranapanema River tributaries, including the Cinzas, Jaguariaíva and Tibagi rivers (e.g., Shibatta et al 2002, Castro et al 2003, Cetra et al 2012, Cionek et al 2012, Costa et al 2013, Hoffmann et al 2005, Cetra et al 2016, Frantine-Silva et al 2015, Almeida et al 2018, Jerep & Shibatta 2017, Claro-García et al 2018, Frota et al 2020, Jarduli et al 2020. However, a comprehensive checklist of the Laranjinha River ichthyofauna has not been published yet, except for a small streams (e.g., Costa et al 2013), and the scientific knowledge of its fish species remains unknown.…”