Phylogeography of the critically endangered neotropical annual fish, Austrolebias wolterstorffi (Cyprinodontiformes: Aplocheilidae): genetic and morphometric evidence of a new species complex

摘要: Austrolebias wolterstorffi is a critically endangered annual fish, occurring in temporary ponds restricted area of Southern Brazil and Uruguay. Here, we evaluate the levels genetic diversity morphometric differentiation presented by A. wolterstorffi, attempting to reconstruct spatiotemporal scenario which this species reached their current distribution. Part mitochondrial cytochrome b nuclear rhodopsin genes were characterized analysed for set 122 110 specimens, respectively, collected along entire distribution range species. Additionally, shape variations evaluated 92 individuals (43 males 49 females) through geometric methods. Our analyses demonstrated several cases significantly high among individual populations, an isolation-by-distance pattern divergence, with at least six different population groups Patos-Mirim lagoon. These differed minimum 0.9% maximum 2.6% corrected cyt nucleotide distances did not share any haplotype. Such pattern, added slight detected most groups, suggests occurrence incipient speciation as consequence allopatric fragmentation. The chronophylogenetic tree performed concatenated dataset supported independent oriental occidental colonization routes, located northwest part Rio Grande do Sul coastal plain presenting ancient divergence. In general, recovered biogeographic patterns are highly consistent records Quaternary climatic changes depositional events that have occurred inhabited studied This allowed us establish molecular clock calibration system Neotropical fish. Thus, although taxonomic status each units needs further study, it clear conservation strategies must be taken major areas covered Brazil.