Advances in genetic knowledge for the management & conservation of the Sonoyta River Mexican Longfin dace, Agosia chrysogaster in Northwest Mexico

Authors: Alejandro Varela-Romero, Marisol Paredes-Gallardo, Carlos Ballesteros-Córdova, Manuel Grijalva-Chon, Enrique Re-Vega, Alexsandre Gutiérrez-Barragán, Nélida Barajas-Acosta

Year: 2022

Abstract

The Sonoyta River Basin is a binational watershed and home native Sonoyta pupfish, Cyprinodon eremus, and the Sonoyta River Mexican Longfin dace, Agosia chrysogaster, that evolved to survive the harsh conditions of the Sonoran Desert. Due to the decline of both, refuge network was built in Sonora with individuals from the Sonoyta River as a conservation strategy between 2007 to 2010. However, its establishment did not consider well the genetic variability of the source population. We evaluated the specific identity and phylogenetic affinity of A. chrysogaster populations of wild population and refuge using mitochondrial (Cytb and COXI) and nuclear DNA (RAG1). For the Longfin dace we find monophyly for all populations without geographic clades. The mitochondrial and nuclear signal support an independent clade of the Sonoyta River (Refuge), nested within all the individuals analyzed. The genetic variability was high between populations and high genetic differentiation. The barcode (COX1) showed fixed polymorphism showing divergence in specimens analyzed of the Sonoyta River (CEDO) population and does not share haplotypes with the rest of the basins and the genetic diversity was zero. The Sonoyta population divergence needs to be verified with additional genetic marker (Genome) and morphological evidence, without delaying urgent recovery and conservation efforts for this unique captive population.