Résumé
Protogamasellopsis zaheri (Rhodacaridae) is one of the mesostigmatid species most frequently and abundantly found throughout Brazil. The objective of this work was to study the morphological and molecular characteristics of specimens from four Brazilian bioma (Caatinga, Cerrado, Atlantic Forest and Pantanal). Specimens from rearing colonies were mounted on slides for measurements of selected structures using a graduated eyepiece. No major morphological differences were observed, suggesting that all the mites belong to the same species. In regards to the molecular analyses, total genomic DNA was extracted using a QIAGEN DNeasy kit. Five DNA fragments were amplified (the mitochondrial fragments mtDNA Cytb, 12S rRNA and COI, and the nuclear fragments 28S, ITSS) and sequenced. Genetic distances were calculated applying the Kimura-two-parameter (K2P) and phylogenetic trees were constructed (Maximum Likelihood). The specimens collected in the Caatinga, Atlantic Forest and Pantanal were very similar, genetic distance being close to 0% for all the DNA markers used. The specimens collected in Cerrado were however very different from specimens from the other locations. The mean genetic distance between Cerrado specimens and the others were very high for all primers (mean genetic distance were between of 0.150 for the marker 28S and of 0.269 for the marker Cytb). Such genetic distances correspond to interspecific distances, suggesting that the specimens from Cerrado are actually another species. New morphological observations confirmed this conclusion and this new cryptic species is morphologically distinguishable mainly by the greater length of the setae on podonotal and opistonotal shields, especially of the "S".