Among the more than 30 families of the order Siluriformes, Heptapteridae is composed of 189 species distributed into 24 genera. Rhamdia, which has wide distribution throughout the Neotropical region, presents only 11 valid species, with 8 being in the Brazilian territory. Rhamdia quelen is the only species considered as widely distributed in almost all Brazilian hydrographic basins. It is a Neotropical fi sh species with a confusing taxonomical history. Classic and molecular cytogenetics data for three populations of this species from two large Brazilian hydrographic basins (Paraná and Araguaia) are presented here. The diploid number found for the three analyzed populations was 58 chromosomes, but with distinct karyotypic formulae. The presence of B chromosomes was detected in the two Araguaia River populations with intra-and interindividual variation. C-banding evidenced little heterochromatin in the three analyzed populations. FISH with 18S rDNA probes evidenced a single chromosome pair bearing this site, confi rming the presence of simple NORs, as visualized through silver nitrate staining. The site of 5S rDNA was observed in only one pair of chromosomes, but differing in the marked pair and their location. Based in the differences of the karyotypic formulae and rDNA 5S found between populations on this study and many others available in the literature, it is suggested that this group represents a species complex, and that a new and detailed taxonomical review is necessary.

These results provide support for the assessment of handgrip strength in all maintenance hemodialysis patients for early identification of those who may require special care to improve nutritional status and survival.

Greater physical activity assessed by PAEE was associated with indicators of better nutritional and inflammation status. These results indicate opportunities for improving outcomes in MHD patients by counseling and treatment intervention.

The results are consistent with the hypothesis that low serum phosphate is associated with low protein and calorie intake only among MHD patients not on binders. This study supports recommendations to prevent hyperphosphatemia in MHD patients by adequate combination of binder use and selection of foods restricted in phosphors but not severely restricted in protein and calories.