Most species of the genus Harttia inhabits the headwaters of small tributaries, but some species are restricted to the main channel of some rivers. This feature, combined with limited dispersal ability, leads to the formation of small isolated populations with reduced gene flow. Currently, there are 23 taxonomically defined and recognized species, and 17 of these are found in Brazil, distributed in several hydrographic basins. Despite this diversity, few chromosomal data for the species belonging to this genus are found in the literature. Thus, this study analyzed, by classical and molecular cytogenetics methodologies, the chromosomal diversity of this genus, to discuss the processes that are involved in the evolution and karyotype differentiation of the species of the group. Seven species of Harttia were analyzed: H. kronei, H. longipinna, H. gracilis, H. punctata, H. loricariformis, H. torrenticola, and H. carvalhoi. The chromosomal diversity found in these species includes different diploid and fundamental numbers, distinct distribution of several repetitive sequences, the presence of supernumerary chromosomes in H. longipinna and multiple sex chromosome systems of the type XX/XYY in H. carvalhoi and XXXX/XXY in H. punctata. Lastly, our data highlight the genus Harttia as an excellent model for evolutionary studies.

Phylogenetic relationships and identification of species of the genus Hypostomus is still unclear. Considering this, cytogenetics may prove itself as an important tool in understanding the systematic of this genus. Reviews in Hypostomus indicate that the diploid number ranges from 54 to 84 chromosomes, and the increase in diploid number has been associated to higher percentages of subtelocentric and acrocentric chromosomes. Although there is a high number of species in the genus, there are relatively few papers concerning Hypostomus cytogenetics, and most of the data is published as grey literature. With the aim to understand the chromosomal evolution in the genus (correlation between diploid number x chromosomes types), H. ancistroides and H. topavae from the Piquiri River, Upper Paraná River basin, were cytogenetically analyzed, and the diploid number observed was 68 and 80 chromosomes, respectively. Additional data on the diploid number and chromosome formulae was compiled from papers (27 analyses) and abstracts from grey literature (77 analyses). Our analysis shows no correlation between chromosome numbers and percentages of subtelocentric and acrocentric chromosomes for most of the species, since there is considerable variation between these percentages even between species with the same diploid number, indicating that the proportion of chromosome types is not always associated to diploid numbers.

Hypostomus is a diverse group with unclear aspects regarding its biology, including the mechanisms that led to chromosome diversification within the group. Fluorescence in situ hybridization (FISH) with 5S and 18S rDNA probes was performed on ten Hypostomini species. Hypostomus faveolus, H. cochliodon, H. albopunctatus, H. aff. paulinus, and H. topavae had only one chromosome pair with 18S rDNA sites, while H. ancistroides, H. commersoni, H. hermanni, H. regani, and H. strigaticeps had multiple 18S rDNA sites. Regarding the 5S rDNA genes, H. ancistroides, H. regani, H. albopunctatus, H. aff. paulinus, and H. topavae had 5S rDNA sites on only one chromosome pair and H. faveolus, H. cochliodon, H. commersoni, H. hermanni, and H. strigaticeps had multiple 5S rDNA sites. Most species had 18S rDNA sites in the telomeric region of the chromosomes. All species but H. cochliodon had 5S rDNA in the centromeric/pericentromeric region of one metacentric pair. Obtained results are discussed based on existent phylogenies for the genus, with comments on possible dispersion mechanisms to justify the variability of the rDNA sites in Hypostomus.

Hypostominae is the largest subfamily of Loricariidae, and is widely distributed throughout the Neotropic. In the present article, we analyze three Loricariidae species that were considered part of Hypostominae, from three different tribes, to discuss chromosome evolution in this fish group and to review the existent data for the subfamily. Rhinelepis aspera had 54 chromosomes (20m + 26sm+8st), whereas Pterygoplichthys ambrosettii and Megalancistrus parananus had 52 chromosomes, with 16m+24sm+8st+4a and 18m+24sm+10st, respectively. The karyological data were compared with existent phylogenetic hypotheses, indicating a common ancestor with 2n = 52 chromosomes for the Acanthicus, Hemiancistrus, and Peckoltia clades, as well as for Hypostomini. Shared recurrent characteristics of the tribes are discussed, as well as peculiarities of genera Ancistrus and Hypostomus. We propose that the occurrence of fragile sites demonstrated for Ancistrus facilitated chromosomal rearrangements that decreased the proportion of metacentric/submetacentric chromosomes and the diploid number in many species from this genus. Although Hypostominae is usually considered a subfamily with derived chromosome features, our revision shows that this is valid only for Hypostomini and Ancistrini, which have a divergent chromosome evolution from other tribes that seems to conserve plesiomorphic features.

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Comparison of feeding habits and physiCal aCtivity between eutrophiC and overweight/obese Children and adolesCents: a Cross seCtional study rev assoC Med bras 2015; 61(3):227-233 227 ORIGINAL ARTICLEComparison of feeding habits and physical activity between eutrophic and overweight/obese children and adolescents: a cross sectional study Conflit of interest: noneObjectives: it is broadly accepted, but little explored, that obese children practice less physical activity and eat more. This study has the objective of comparing feeding habits and physical activity between eutrophic and overweight/obese children and adolescents. Methods: 126 students with ages ranging from 6 to 18 years were evaluated. Eutrophic and overweight/obese students were compared according to calorie intake, macro and micronutrients, prevalence of physical inactivity and ingestion of micronutrients. Results: differences were observed in the amount of calories ingested per unit of BMI (eutrophic, 97.6, and overweight/obese, 70.5, p=0.0061), as well as in calcium intake (eutrophic, 546.2, and overweight/obese, 440.7, p=0.0366). Both groups presented sedentarism, as well as a high prevalence of micronutrient intake deficiency, especially calcium and vitamins A, E, and C, but with no difference observed between eutrophic and overweight/obese subjects. Conclusion: energy and macronutrients consumption, as well as physical activity, were similar between eutrophic and overweight/obese. Calcium intake was lower in the overweight/obese group and the ingestion of vitamin C was lower in the eutrophic group. These results demonstrate the importance of considering all etiologic factors that may lead to obesity, so that new strategies for prevention and control may be added to traditional interventions.

The karyotype of the Ancistrini catfish Ancistrus taunayi was analyzed by conventional (Giemsa staining, AgNOR staining and C-banding) and molecular cytogenetic (5S and 18S rDNA-FISH) methods. The diploid chromosome number was 2n = 50 (22 metacentrics + 10 submetacentrics + 10 subtelocentrics + 8 acrocentrics) for both sexes. A single NOR-bearing acrocentric chromosome pair (No. 24) was detected after Ag-staining and 18S rDNA-FISH, while 5S rDNA was found only in the subtelocentric pair No. 21. Conspicuous GC-rich heterochromatin blocks corresponded to the NOR sites and were also observed in the distal regions of the acrocentric chromosome pairs Nos. 22 and 25. Chromosome pair No. 22 differed between males and females; in males, only a small interstitial block of GC-rich heterochromatin was present in both chromosomes, whereas in females, 2 blocks of GC-rich heterochromatin flanked a euchromatic region in one of the homologues, suggesting the occurrence of a ZZ/ZW sex chromosome system. Two mechanisms for the origin and evolution of this simple ZZ/ZW sex chromosome system in A. taunayi are proposed: (1) a paracentric inversion followed by amplification of the proximal heterochromatin and (2) amplification of the interstitial heterochromatin followed by a paracentric inversion. Although ZZ/ZW systems have already been described for other Ancistrus species, our results do not show the same pattern, suggesting an independent origin.

The Callichthyinae subfamily is composed of five genera with a small number of described species. Molecular cytogenetics studies show the scarcity of records for this subfamily. The aim of the present study was to employ cytogenetic parameters in the analysis of three species belonging to the subfamily Callichthyinae sampled from the Paraná River (Brazil). Callichthys callichthys had 2n = 56 chromosomes (26 m-sm + 30 st-a); Lepthoplosternum pectorale had 2n = 64 chromosomes (8 m-sm + 56 st-a); and Hoplosternum littorale had 2n = 60 chromosomes (8 m-sm + 52 st-a). Regarding the location of the nucleolar organizer regions (NORs) (Ag-staining and 18S rDNA-FISH), different situations were found: single NORs in H. littorale and C. callichthys; multiple NORs in L. pectorale, with intra-individual and inter-individual variation. Heterochromatin was observed in the centromeric region in the chromosomes of the three species. Equilocal, interstitial bands were also found in H. littorale. Physical mapping of 5S ribosomal genes by FISH shows eight 5S rDNA sites in C. callichthys; four 5S rDNA sites in H. littorale and six 5S rDNA sites in L. pectorale. Using cytogenetic markers (diploid number, chromosome formula, NORs, heterochromatin distribution pattern and 5S and 18S rDNA sites), the chromosomal evolution in Callichthyinae is presented: Callichthys shows mostly basal chromosomal conditions, with mostly derived chromosomal conditions verified for the Hoplosternum-Dianema clade and Megalechis-Lepthoplosternum clade.