https://revistaschilenas.uchile.cl/handle/2250/40885 [0-9]{4} Sun, 10 May 2026 21:35:32 GMT 2026-05-10T21:35:32Z https://revistaschilenas.uchile.cl:443/bitstream/id/9528ff87-70c8-476f-80e8-65f88557d068/ https://revistaschilenas.uchile.cl/handle/2250/40885 https://revistaschilenas.uchile.cl/handle/2250/63225 Heavy metal biomagnification and genotoxic damage in two trophic levels exposed to mine tailings: a network theory approach Abstract Background The analysis of the negative effects of environmental metal pollution is complex and difficult to assess, because the great number of variables and levels of biological organization involved. Therefore, an integral interpretation of the structure of ecological interactions from the multifactorial toxicological vision can be achieved by the use of new analysis tools, such as the complex network theory analysis (CNT). Results Our results demonstrated that the trophic level has an effect on metal enrichment, being the detritivores who presented the highest bioaccumulation levels in comparison to plants, as well as higher biomagnification levels in the soil-plant-detritivores relationship. Also, Vachellia farnesiana displayed greater sensitivity to genotoxic damage than Eisenia fetida. Finally, the analysis of complex networks showed that detritivores are the key link in this dynamics, on which the interactions between heavy metals, plant and detritivores depend. Conclusions This study shows that there is an effect of the study site on heavy metal bioaccumulation and DNA damage induction, and that these responses are particular to each species and to each bioaccumulated metal, which in turn reveals specific sensitivity for each trophic level. Moreover, the application of CNT methodology allowed us to clarify in this particular system, the interaction types and the principal components of the trophic structure. https://revistaschilenas.uchile.cl/handle/2250/63225 https://revistaschilenas.uchile.cl/handle/2250/63226 Ultrastructure of sensilla on antennae and maxillary palps in three Mesembrinellidae species Abstract Background Having the right identification is essential in the field of entomology. The scanning electron microscopy allows rapid and accurate identification of different species of flies since a better visualization of the external morphology of immature and some adults is possible. The aim of this study is to describe some ultrastructures of three flies in the Mesembrinellidae family: Mesembrinella bellardiana; Mesembrinella bicolor and Mesembrinella semihyalina, all examined by scanning electron microscopy to help increase the anatomical database on flies and deal with phlylogenetic implications. Results The flies were examined under JEOL 6390LV scanning electron microscope (SEM). The microtrichia morphology of the antennae is similar to that of other and are present on all antennal surface with variable distribution. The chaetic sensilla were observed only in the scape (chaetic sensilla I) and pedicel segments (chaetic sensilla I-III). Three types of sensilla: trichoidea, basiconic and clavate were observed in the first flagellomere of M. bellardiana; and two types of sensilla: trichoidea and basiconic were noticed in M. bicolor and M. semihyalina. Olfactory pits were observed in both gender of M. bellardiana and female of M. bicolor . The maxillary palp of the Mesembrinella species in this study does not show sexual dimorphism. Conclusion This investigation provided new findings of some diagnostic structures of flies using SEM, since many of them could have not been observed just by the use of light microscopy. https://revistaschilenas.uchile.cl/handle/2250/63226 https://revistaschilenas.uchile.cl/handle/2250/63227 Evolution of trans-Andean endemic fishes of the genus Cheirodon (Teleostei: Characidae) are associated with chromosomal rearrangements Abstract Background Among Neotropical fishes, the family Characidae is highly diverse and speciose and its taxonomy is not completely resolved. In Chile, the family is represented by five species, all within the genus Cheirodon , of which C. pisciculus, C. galusdae, C. kiliani , and C. australe are endemic , while C. interruptus is introduced. We compared chromosomal markers in order to appreciate the taxonomy and evolution of these trans-Andean fishes. Results The specimens were photographed in stereomicroscope to observe the ventral protrusive teeth and cusps for morphological analysis and species identification. All of the species analysed had equally diploid chromosome number 2n = 50, with karyotypes dominated by high number of acrocentric chromosomes as compared to those of other members of Cheirodontinae. The distribution of heterochromatin was inconspicuous and was similar in all the species. The number of active NORs (nucleolus organizer regions) was polymorphic, with the greater number of them in C. kiliani and C. galusdae . The location of 5S and 18S rDNA ranged in number and position, showing two sites in different chromosomes. The fluorescent in situ hybridization with telomeric probe did not reveal interstitial sites in all analysed species. Conclusions The comparative analysis of karyotypes and morphological markers revealed a biogeographic pattern of distribution, with the species that occur in the southern region forming one group and those in central and northern Chile forming another. https://revistaschilenas.uchile.cl/handle/2250/63227 https://revistaschilenas.uchile.cl/handle/2250/63228 Frugivory and seed dispersal in the endemic cactus Eulychnia acida: extending the anachronism hypothesis to the Chilean Mediterranean ecosystem Abstract Background: Eulychnia acida is an endemic Chilean cactus species whose fruits show several traits that, taken as a whole, are compatible with a seed dispersal syndrome by large herbivore vertebrates. Since only a few large native mammals exist in Chile at present, cactus fruit consumption and seed dispersal may be coopted by introduced mammals as predicted by Janzen and Martin's (1982) hypothesis for tropical ecosystems. Findings: We describe the current frugivore species of E. acida in a protected semiarid-Mediterranean ecosystem using field measurements and feeding experiments. In addition, to examine a potential role as seed dispersers of the cactus species, we offered fruits and performed germination tests on seeds defecated by Lama guanicoe and the introduced goat Capra a. hircus under captivity conditions. Our data indicate that while fruits of E. acida are pecked by the Chilean tinamou, Nothoprocta perdicaria, and the Chilean mockingbird, Mimus thenca, and eaten by the brush-tailed rodent, Octodon degus, none of these species could be considered a legitimate seed disperser. Unlike L. guanicoe, the goat C. a. hircus did not reduce seed germination, having a neutral effect. Conclusions: Results from this study indicate that introduced C. a. hircus was the only species showing a potential role in the seed dispersal process of E. acida. In the absence of native frugivore species, goats might play an important role in population recruitment of the endemic cactus. These results extend Janzen and Martin's(1982) anachronism hypothesis to the Chilean Mediterranean ecosystem. https://revistaschilenas.uchile.cl/handle/2250/63228