Resumen:
Nematodes are the most abundant metazoans in the planet. It is estimated that three-quarters or more of all land animals are nematodes. They can be found in all habitats that provide sources of organic carbon available. They still vary according to the sensitivity to pollutants and environmental disturbance. For these reasons it is being used as an instrument for biomonitoring ecosystems. The taxonomic resolution reduces the problem of "taxonomic impediment" caused by the scarcity of researchers in this area and the difficulty in identifying organisms at lower taxonomic levels. Thus, this study aimed at comparing the nematofaunistic population structures through the use of taxonomic resolutions in three coastal environments in order to expand the use of taxonomic resolution and emphasize its importance as a good resource support in the researches of taxonomic aspects, especially in those involving environmental monitoring. Samplings in rainy and dry season were made, in a fixed point at the beach, of the reef and estuary of Pirangi do Sul - RN, Brazil. The found nematodes were identified up to the species level. They were found 46 genera belonging to 15 families and 56 species being 9 of them new to science. Statistical analyzes showed that the taxonomic levels used in this research point to differences in the community´s organization, among the sampling stations, except the specific level. Differences were also observed for spatial analysis, with the exception of the order level. Classification up to the genus level has shown taxonomically enough to interpret the data nematofaunistic community of Pirangi-RN southern region for spatial analysis.
