4 research outputs found

    INFLUÊNCIA DE VARIÁVEIS AMBIENTAIS NAS FUNÇÕES ECOLÓGICAS DE ESCARABEÍNEOS EM SISTEMAS DE USO DO SOLO NO CAPARAÓ CAPIXABA

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    As funções ecológicas realizadas pelos besouros escarabeíneos, ou “rola-bostas”, foram estudadas nos três principais sistemas de uso do solo da região do Caparaó Capixaba: lavouras de café, pastagens e fragmentos florestais. Nos ambientes de florestas foi observada uma maior quantidade média de fezes enterradas em relação aos cafezais, já nas pastagens não houve diferenças significativas com os demais sistemas de uso do solo. As correlações entre as variáveis ambientais e as funções ecológicas estudadas puderam nos mostrar a influência da composição do solo e do tipo de vegetação sobre o enterrio de fezes e revolvimento do solo realizados pelos besouros. A complexidade da vegetação, medida através da dimensão fractal da vegetação indicou uma maior complexidade estrutural na floresta em relação à pastagem. O trabalho auxiliou no entendimento do funcionamento dos principais sistemas de uso do solo da região do Caparaó Capixaba

    Diversité Cryptique, Bioacoustique et Interactions Intra et Interspécifiques dans le Complexe d Espèces Primitives Néotropicales Pachycondyla apicalis (Hymenoptera : Formicidae : Ponerinae)

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    La région Néotropicale abrite une extraordinaire diversité biologique, dont une grande partie encore non identifiée. En outre, parmi les espèces déjà inventoriées, plusieurs groupes sont soumis à des classifications imparfaites. Ceci est particulièrement dû à l'existence d'espèces cryptiques formant des complexes d'espèces qui empêchent l évaluation correcte de la biodiversité. Les fourmis primitives du complexe Pachycondyla apicalis sont un bon exemple de ce fait et leur taxonomie n est pas consensuelle. Etant donné que l'identification exacte des espèces est essentielle à la fois à la recherche dans tous les domaines de la biologie et à la conservation de la biodiversité, l un des objectifs premiers de ce travail a été la détermination de la diversité cryptique au sein de ce complexe d espèces. L étude des organes producteurs de son et des signaux stridulatoires ont démontré que ces espèces morphologiquement semblables possèdent des différences spécifiques nettes dans leurs systèmes de communication acoustique respectifs. Les résultats acoustiques ont été corroborés par des analyses moléculaires, confirmant ainsi que la bioacoustique est un outil potentiel pour la détermination des espèces cryptiques dans ce groupe de fourmis. Ce résultat est la première indication d'un tel degré de spécialisation dans les signaux stridulatoires des fourmis, ce qui suggère que les stridulations peuvent présenter un rôle encore plus important dans la vie de ces espèces. Bien qu indiscernables pour l'œil humain, ces espèces cryptiques sont évidemment dissemblables les unes des autres. De ce fait, nous avons pu au travers d études bioacoustiques, génétiques, chimiques, écologiques et comportementales caractériser des éléments de la biologie de ces espèces pouvant être considérés comme indicateurs de l espèce, et ceci également dans le but de mieux comprendre les interactions intra- et interspécifiques dans ce groupe d espèces phylogénétiquement proches.The Neotropical region is home to an extraordinary biological diversity, much of which still unidentified. In addition, among the species already described, several groups are subject to imperfect classifications. This is particularly due to the existence of cryptic species which form species complex that prevent the correct assessment of biodiversity. The primitive ants from the Neotropical Pachycondyla apicalis complex are a good example of this fact and their taxonomy is still unsolved. Since the correct identification of species is essential both for research in all fields of biology and the conservation of biodiversity, one of the primary objectives of this work was the determination of cryptic diversity within this species complex. The study of the stridulatory organs and signals showed that these morphologically similar species have clear specific differences in their respective acoustic communication systems. The acoustic results were corroborated by molecular analysis, confirming bioacoustics as a potential tool for the determination of cryptic species in this group of ants. This is the first indication of such a degree of specialization in the stridulatory signals of ants, suggesting that stridulations may have an even more important role in the lives of these species. Even if indistinguishable to the human eye, these cryptic species are obviously dissimilar from each other. Thus we were able through acoustic, genetic, chemical, ecological and behavioural studies to characterize biological elements of these species that can be considered as indicators of the species, and this also in order to better understand intra and interspecific interactions in this group of phylogenetically related species.PARIS13-BU Sciences (930792102) / SudocSudocFranceF

    Temporary prey storage along swarm columns of army ants: an adaptive strategy for successful raiding?

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    While pillaging the brood of other ant colonies, Eciton army ants accumulate prey in piles, or caches, along their foraging trails. Widely documented, these structures have historically been considered as by-products of heavy traffic or aborted relocations of the ants' temporary nest, or bivouac. However, we recently observed that caches of the hook-jawed army ant, Eciton hamatum, appeared independently from heavy traffic or bivouac relocations. In addition, the flow of prey through caches varied based on the quantity of prey items workers transported. As this suggested a potential adaptive function, we developed agent-based simulations to compare raids of caching and non-caching virtual army ants. We found that caches increased the amount of prey that relatively low numbers of raiders were able to retrieve. However, this advantage became less conspicuous-and generally disappeared-as the number of raiders increased. Based on these results, we hypothesize that caches maximize the amount of prey that limited amounts of raiders can retrieve, especially as prey colonies coordinately evacuate their brood. In principle, caches also allow workers to safely collect multiple prey items and efficiently transport them to the bivouac. Further field observations are needed to test this and other hypotheses emerging from our study.Nanyang Technological UniversityA CNPq Productivity grant (PQ-2017 grant no. 311790/2017-8) to N.C.; a CAPES PROEX Psicologia Experimental 2016/1964 to N.C., H.P.d.L., R.S.F.-C., R.L.C.d.L. and PROCAD Amazônia; a Presidential Postdoctoral Fellowship (M408080000) from Nanyang Technological University to S.T. CNPq provided H.P.d.L.’s PhD scholarship

    Permanent genetic resources added to Molecular Ecology Resources Database 1 October 2010-30 November 2010

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    This article documents the addition of 277 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Ascochyta rabiei, Cambarellus chapalanus, Chionodraco hamatus, Coptis omeiensis, Cynoscion nebulosus, Daphnia magna, Gerbillus nigeriae, Isurus oxyrinchus, Lates calcarifer, Metacarcinus magister, Oplegnathus fasciatus, Pachycondyla verenae, Phaethon lepturus, Pimelodus grosskopfii, Rotylenchulus reniformis, Scomberomorus niphonius, Sepia esculenta, Terapon jarbua, Teratosphaeria cryptica and Thunnus obesus. These loci were cross-tested on the following species: Austropotamobius italicus, Cambarellus montezumae, Cambarellus puer, Cambarellus shufeldtii, Cambarellus texanus, Chionodraco myersi, Chionodraco rastrospinosus, Coptis chinensis, Coptis chinensis var. brevisepala, Coptis deltoidea, Coptis teeta, Orconectes virilis, Pacifastacus leniusculus, Pimelodus bochii, Procambarus clarkii, Pseudopimelodus bufonius, Rhamdia quelen, Sepia andreana, Sepiella maindroni, Thunnus alalunga, Thunnus albacares, Thunnus maccoyii, Thunnus orientalis, Thunnus thynnus and Thunnus tonggol
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