Ecofisiologia evolutiva de Heliconius : morfometria das asas, metabolismo do voo, do comportamento canibal e aclimatação a diferentes temperaturas

Abstract

The study of Heliconius mimicry has always received much attention. New relationships among species of the genus are discovered in exquisite studies. However, there are few investigations regarding the group’s Physiology. The relationship established between Heliconius species, forming mimetic rings, occurs both between species belonging to the same clade, as in phylogenetically distant species. In this thesis we studied three species of Heliconius from southern Brazil relating Physiology and morphology with mimicry. We sought to know whether the existing mimicry between the mimetic pair Heliconius besckei (silvaniform clade) and Heliconius erato phyllis (pupal mating clade) remains in other characteristics beyond the wing coloration pattern. In addition, we investigated whether H. besckei diverges in these same physiological and morphological parameters of the species H. ethilla narcaea, which also belongs to the silvaniform clade and as well as H. e. phyllis is sympatric with H. besckei in southern Brazil. Ultrastructural analysis methods were used to investigate the butterflies’ musculature of the thorax, as well as the study of biochemical markers linked to the oxidative balance and to the intermediate metabolism. For morphological analysis, we used geometric morphometry on the wings of the three species to evaluate shape and size. Our results showed that the species H. besckei converged with its mimetic pair H. erato phyllis, beyond the coloration pattern, in flight type, size and shape of anterior wings, body mass (thorax and abdomen), besides some markers of oxidative balance (TBARS, SOD and GST) and intermediate metabolism (total protein content, total lipids, triglycerides, cholesterol and glycogen). However, due to constraints to environments with altitudes higher than 700m, the physiological requirements of H. besckei to live in sympathy with the mimetic species seem costly. Thus, some parameters such as mitochondrial area, catalase activity and uric acid and lactate levels were divergent. In addition, we also investigated the biochemical markers of caterpillars and pupae of H. e. Phyllis in relation to the cannibal behavior that they present as 1st instar larvae. Our results did not show significant differences between animals that presented cannibal and not cannibal behavior on the markers of oxidative stress and metabolism. However, cholesterol levels are lower and GST is higher in 4th instar caterpillars that did not show cannibal behavior. These results are interesting when we analyze the development time per instar, where individuals with cannibal behavior undergo ecdysis more quickly from 1st to 2nd instar. We also analyzed the response of H. ethilla narcaea caterpillars to two temperatures (19º and 20 ºC) of environments in which they are normally found. We recorded that 5º instar caterpillars maintained at 24ºC presented reduced body mass and reduced levels of lactate when compared to caterpillars maintained at 19ºC. We did not obtain differences in relation to oxidative balance markers, which together with the other results may indicate that caterpillars maintained at warmer temperatures possibly adjust their behavior, their metabolic activity, prioritizing through ingestion the accumulation of antioxidant 16 molecules from food (Passiflora edulis), in this way they can stop the increase of ERO. Our results are new, important and original sources of information on the species of Heliconius and specially on the species occurring in southern Brazil.