Diversidad y estructura genética del Macrobrachium americanum (Bate, 1868) en dos regiones geográficas en México

Abstract

Objective. To analyze the population genetics using mitochondrial molecular markers (16S mtDNA and COI mtDNA) of the river prawn Macrobrachium americanum across two different geographic areas in Mexico: Baja California Sur (San Pedro de la Presa and Guamuchil Oasis) and Guerrero (Aguas Blancas River). Materials and Methods. We calculated the number of haplotypes (H), haplotype diversity (Hd), nucleotide diversity (π), and the number of nucleotide differences (k) for each sampling site using the program Dnasp. To determine the two haplotype networks (COI and 16s rDNA), we employed the median-joining method implemented in PopArt 1.7. Analysis of molecular variance (AMOVA) and pairwise ΦST statistics between pairs of sampled sites were estimated using ARLEQUIN 3.5. Statistical significance was tested with 10,000 permutations in both methods of analysis. Results. The number of Haplotypes (h), Haplotypic diversity (Hd), and nucleotide diversity (π) indicated similar genetic diversity observed for other Decapoda and other Macrobrachium prawns, registering high values (COI Hd=0.98, π=0.019; 16S Hd=0.66, π=0.002). Haplotype networks and molecular variance analysis did not show patterns of genetic structure among the populations of M. americanum from the geographic areas nor within the studied Oasis (COI ΦST=-0.002, 16S ΦST=0.021, p≥0.140). Still, the results suggest recent and historical population expansions. Conclusions. This analysis reveals high genetic diversity and both recent and historical population expansion, which enhance adaptability. Despite high variability and the presence of panmixia, effective dispersal mechanisms have been observed. These findings provide valuable information for aquaculture, genetic improvement programs, and repopulation efforts of M. americanum.