GENETIC DIFFERENTIATION OF THE MILLIPEDE PYCNOTROPIS-EPICLYSMUS INHABITING SEASONALLY INUNDATED AND NON-FLOODED AMAZONIAN FORESTS

The millipede Pycnotropis epiclysmus Hoffman, 1995 (Diplopoda: Polydes mida: Platyrhacidae) is frequently found in Central Amazonian white- a nd mixed-water inundation forests along the Solimoes-Amazon River near Manaus, Brazil. It also inhabits non-flooded disturbed forest areas a djacent to this river. Populations from both biotopes were genetically studied. The specific pPeP172 satellite DNA family identified in P. e piclysmus has been analyzed in order to elucidate the systematic rank of morphologically indistinguishable individuals from the different ha bitat types. Nucleotide sequence data, sequence variability and copy n umber estimates of the pPeP172 satellite DNA do not discriminate the r espective populations into genetically different ecotypes. The study o f enzyme variability, however, revealed genotypic differences among th e three populations: the populations from two geographically more dist ant inundation forests are genetically rather similar; and the geograp hically closer populations, one found in a non-flooded and the other i n an inundation forest, have a genetic distance which is of similar ma gnitude to that of the two geographically more distant populations. Th e genetic data suggest that individuals from different habitats belong to populations of a single species. Genotypic structuring among and w ithin local populations indicates processes of genetic differentiation which can be the result of the migration ability of this millipede.