RESUMO

In this work, we analyzed cytogenetically eight Chactidae and Buthidae, including the localization of repetitive DNA sequences. The chactids possess monocentric chromosomes and the highest diploid numbers (2n=50 in Brotheas amazonicus, 2n=36 in Chactopsis amazonica, 2n=30 in Neochactas sp.) when compared with buthids (2n=10 in Tityus bahiensis, 2n=14 in Tityus apiacas and Tityus metuendus, 2n=18 in Tityus aba, 2n=26 in Ischnotelson peruassu). The localization of rDNA genes and (TTAGG)n sequences exhibited a conserved pattern of two terminal/subterminal ribosomal cistrons and terminal telomere signals. However, the comparison between the data of C-banding, DAPI after FISH and Cot-DNA fraction indicated a variable quantity and distribution of these regions, as follow: (i) positive heterochromatin and Cot-DNA signals (B. amazonicus and I. peruassu), (ii) small blocks of heterochromatin with large Cot-DNA signals (T. metuendus), (iii) positive heterochromatic regions and absence of Cot-DNA signals (T. aba and T. apiacas), and (iv) negative heterochromatin and Cot-DNA signals (T. bahiensis). Therefore, our results revealed that there still is not a clear relation between quantity of heterochromatin and presence of monocentric or holocentric chromosomes and occurrence of chromosomal rearrangements, indicating that repetitive regions in scorpions must be analyzed using different cytogenetic approaches.

RESUMO

The Serra de Piquiatuba is situated in the area of the 8th Battalion of Engineering and Construction—8° BEC, located at km 8 of the Santarém–Cuiabá highway, in the municipality of Santarém, Pará, Brazil. This region is characterized by a hot and humid climate with rainfall exceeding 1900 mm p.a. In this study, we present a species list of scorpions from the Serra de Piquiatuba, based on data collected from September to November 2010. Five species were recorded, all common in the Amazon, belonging to the families Buthidae and Chactidae. The observed diversity patterns are discussed considering other scorpion inventories carried out in Brazil and possible sampling biases. The present study raises methodological questions to be further addressed in scorpion community ecology studies.

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Aunque Brasil tiene una de las diversidades de escorpiones más altas del mundo, la fauna de escorpiones de la región amazónica sigue siendo relativamente poco descrita. En este estudio, actualizamos la lista de especies de escorpiones para el estado de Acre, en el suroeste de la Amazonía brasileña, en base a una revisión de los registros contenidos en colecciones de arácnidos brasileños y un estudio de la literatura relevante. Registramos la ocurrencia de siete especies de escorpiones pertenecientes a dos familias (Buthidae y Chactidae), entre las cuales informamos tres nuevos registros (Ananteris sp., Tityus (Tityus) gasci y Chactopsis cf. insignis) para Acre. Los resultados presentados aquí hacen una contribución importante al conocimiento acerca de la diversidad de escorpiones en los bosques amazónicos de Acre.(AU)

Although Brazil has one of the highest scorpion diversities worldwide, the scorpion fauna of the Amazon region remains relatively poorly described. In this study, we updated the list of scorpion species from the state of Acre, in the southwestern Brazilian Amazon, based on a revision of records contained in Brazilian arachnid collections and a survey of the relevant literature. We recorded the occurrence of seven scorpion species belonging to two families (Buthidae and Chactidae) among which we report three new records (Ananteris sp., Tityus (Tityus) gasci, and Chactopsis cf. insignis) for Acre. The results presented herein make an important contribution to the knowledge on scorpion diversity in the Amazonian forests of Acre.(AU)

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Os casos de envenenamentos aumentaram consideravelmente no Brasil, no entanto, para o estado do Piauí apenas dois estudos foram realizados até o momento. Aqui, investigamos, através dos formulários de notificação, as características epidemiológicas dos casos de envenenamentos ocorridos durante 11 anos na macrorregião de Picos, estado do Piauí, Nordeste do Brasil. Além disso, também verificamos se as espécies registradas nos formulários de notificação correspondem às espécies que ocorrem na região. Registramos 1.249 casos de envenenamentos, sendo 41% causados por escorpiões, 35% causados por serpentes e 24% causados por aranhas. Na maioria dos casos (aracnídeos = 99%, escorpiões = 93%, serpentes = 52%) não houve a identificação da espécie causadora do acidente. A maioria das vítimas dos acidentes (66%) eram indivíduos do sexo masculino entre 18 e 24 anos de áreas rurais, picadas durante atividades de campo na estação chuvosa (janeiro a março). Os locais de lesão mais comuns foram os membros inferiores (37%) e a maioria (53%) dos acidentes foi do tipo leve. Este é o primeiro estudo que reporta o perfil epidemiológico de uma série de envenenamentos (incluindo aracnídeos e serpentes) durante 11 anos de ocorrência no estado do Piauí. Além disso, também apresentamos a primeira lista de espécies de aracnídeos e serpentes de importância médica para o estado. Nossos resultados demonstram que houve uma alta incidência de acidentes por animais peçonhentos na região centro-sul do estado, a maioria dos registros não foi notificada no SINAN, a maioria dos registros não apresentou a identificação das espécies responsáveis pelo acidente, e há registros cujas espécies foram identificadas incorretamente.(AU)

Cases of poisoning have increased considerably in Brazil, however for state of Piauí only two studies were carried out so far. Here, we investigated, through the notification forms, the epidemiological characteristics of cases of poisoning that occurred during 11 years in a macro-region of Picos, state of Piauí, Northeastern Brazil. Furthermore, we also check whether the species recorded in the notification forms correspond to the species that occur in the region. We recorded 1.249 cases of envenomations, being 41% caused by scorpions, 35% caused by snakes and 24% caused by spiders. Most cases (arachnids = 99%, scorpions = 93%, snakes = 52%) there was no identification of species causing the accident. Most of the victims of the accidents (66%) were male individuals between 18 and 24 years from rural areas, stung during field activities in the rainy season (January-March). The most common injury sites were the lower limbs (37%) and the majority (53%) of the accidents was the mild type. This is the first study that reports the epidemiological profile of a series of envenomations (including arachnids and snakes) during 11 years of records in the state of Piauí. Furthermore, we also present the first list of species of arachnids and snakes of medical importance to the state. Our results demonstrate that there was a high incidence of accidents by venomous animals in the Center-South region of the state, most of the records was not notified in SINAN, most records does not present the identification of the species responsible for the accident, and there are records whose species was incorrectly identified.(AU)

Assuntos

RESUMO

Os casos de envenenamentos aumentaram consideravelmente no Brasil, no entanto, para o estado do Piauí apenas dois estudos foram realizados até o momento. Aqui, investigamos, através dos formulários de notificação, as características epidemiológicas dos casos de envenenamentos ocorridos durante 11 anos na macrorregião de Picos, estado do Piauí, Nordeste do Brasil. Além disso, também verificamos se as espécies registradas nos formulários de notificação correspondem às espécies que ocorrem na região. Registramos 1.249 casos de envenenamentos, sendo 41% causados por escorpiões, 35% causados por serpentes e 24% causados por aranhas. Na maioria dos casos (aracnídeos = 99%, escorpiões = 93%, serpentes = 52%) não houve a identificação da espécie causadora do acidente. A maioria das vítimas dos acidentes (66%) eram indivíduos do sexo masculino entre 18 e 24 anos de áreas rurais, picadas durante atividades de campo na estação chuvosa (janeiro a março). Os locais de lesão mais comuns foram os membros inferiores (37%) e a maioria (53%) dos acidentes foi do tipo leve. Este é o primeiro estudo que reporta o perfil epidemiológico de uma série de envenenamentos (incluindo aracnídeos e serpentes) durante 11 anos de ocorrência no estado do Piauí. Além disso, também apresentamos a primeira lista de espécies de aracnídeos e serpentes de importância médica para o estado. Nossos resultados demonstram que houve uma alta incidência de acidentes por animais peçonhentos na região centro-sul do estado, a maioria dos registros não foi notificada no SINAN, a maioria dos registros não apresentou a identificação das espécies responsáveis pelo acidente, e há registros cujas espécies foram identificadas incorretamente.

Cases of poisoning have increased considerably in Brazil, however for state of Piauí only two studies were carried out so far. Here, we investigated, through the notification forms, the epidemiological characteristics of cases of poisoning that occurred during 11 years in a macro-region of Picos, state of Piauí, Northeastern Brazil. Furthermore, we also check whether the species recorded in the notification forms correspond to the species that occur in the region. We recorded 1.249 cases of envenomations, being 41% caused by scorpions, 35% caused by snakes and 24% caused by spiders. Most cases (arachnids = 99%, scorpions = 93%, snakes = 52%) there was no identification of species causing the accident. Most of the victims of the accidents (66%) were male individuals between 18 and 24 years from rural areas, stung during field activities in the rainy season (January-March). The most common injury sites were the lower limbs (37%) and the majority (53%) of the accidents was the mild type. This is the first study that reports the epidemiological profile of a series of envenomations (including arachnids and snakes) during 11 years of records in the state of Piauí. Furthermore, we also present the first list of species of arachnids and snakes of medical importance to the state. Our results demonstrate that there was a high incidence of accidents by venomous animals in the Center-South region of the state, most of the records was not notified in SINAN, most records does not present the identification of the species responsible for the accident, and there are records whose species was incorrectly identified.

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The recently-revised subfamily Centruroidinae is part of the New World clade of buthid scorpions. In this study, we analyzed the cytogenetic characteristics of nine of the 10 Brazilian centruroidines, and one undescribed species of the genus Ischnotelson, using a phylogenetic approach to determine the chromosomal rearrangements responsible for the differentiation of karyotypes among the species. The cytogenetic data recorded in the present study supported the new taxonomic arrangement of the Centruroidinae, with all the species of the same genus sharing the same or similar diploid numbers, i.e., 2n = 20 or 22 in Troglorhopalurus lacrau and T. translucidus, 2n = 25 or 26 in Ischnotelson sp., I. guanambiensis and I. peruassu, and 2n = 28 in Jaguajir agamemnon, J. pintoi and J. rochae. The karyotype modelling in the ChromEvol software indicated 2n = 18 as the ancestral diploid number of the Centruroidinae. The differentiation of karyotypes among the centruroidine genera was based on increasing chromosome numbers resulting from progressive fission events. These changes probably occurred prior to the diversification of the genera Ischnotelson, Jaguajir, Physoctonus and Rhopalurus, and appear to have played a more important role in karyotype evolution at the intergeneric level than the interspecific one. However, the observed increase in diploid numbers was not accompanied by changes in the number or location of ribosomal genes or telomeric sequences. The identification of meiotic cells in female specimens also allowed us to discuss the mechanisms of achiasmatic meiosis in scorpions.

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Scorpions represent an intriguing group of animals characterized by a high incidence of heterozygous chromosomal rearrangements. In this work, we examined six species of Tityus (Archaeotityus) from Brazilian fauna with a particular focus on elucidating the rearrangements responsible for the intraspecific variability of diploid number and the presence of long chromosomal chains in meiosis. To access any interpopulation diversity, we also studied individuals from four species representing distinct localities. Most species demonstrated intraspecific polymorphism in diploid number (2n = 19 and 2n = 20 in T. clathratus, T. mattogrossensis, and T. pusillus, 2n = 16, 2n = 17 and 2n = 18 in T. paraguayensis, and 2n = 16 and 2n = 24 in T. silvestris) and multi-chromosomal associations during meiosis I, which differed even among individuals with the same chromosome number. In some species, the heterozygous rearrangements were not fixed, resulting such as in Tityus clathatrus, in 11 different chromosomal configurations recognized within a same population. Based on meiotic chromosome behaviour, we suggested that independent rearrangements (fusion/fission and reciprocal translocations), occurring in different combinations, originated the multi-chromosomal chains. To evaluate the effects of these chromosome chains on meiotic segregation, we applied the chi-square test in metaphase II cells. The non-significant occurrence of aneuploid nuclei indicated that non-disjunction was negligible in specimens bearing heterozygous rearrangements. Finally, based on our analysis of many chromosome characteristics, e.g., holocentricity, achiasmate meiosis, endopolyploidy, ability to segregate heterosynaptic or unsynapsed chromosomes, (TTAGG)n sequence located in terminal regions of rearranged chromosomes, we suggest that the maintenance of multi-chromosomal associations may be evolutionarily advantageous for these species.

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Two new species of Bothriurid scorpions, Bothriurus delmari n. sp. and B. aguardente n. sp., are described from Bahia, Northeastern Brazil. These species are included in the asper group owing to the peculiar hemispermatophore morphology. These two newly described species increases to 47 the number of known and valid Bothriurus species. Additionaly, the known distribution of Bothriurus asper is updated.

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RESUMO

Buthid scorpions exhibit a high variability in diploid number within genera and even within species. Cytogenetically, Buthidae differs from other families of Scorpiones based on its low diploid numbers, holocentric chromosomes, and complex chromosomal chains, which form during meiosis. In this study, we analyzed the distribution of the 45S ribosomal DNA (rDNA) genes in the mitotic and meiotic chromosomes of seven buthid species belonging to the genera Rhopalurus and Tityus with the ultimate goal of elucidating the chromosome organization in these scorpions. The chromosome number ranged from 2n=6 to 2n=28. Despite the high variance in diploid number, all species examined carried their 45S rDNA sites in the terminal region of exactly two chromosomes. Analyses of meiotic cells revealed 45S rDNA clusters in the chromosomal chains of Rhopalurus agamemnon, Tityus bahiensis, Tityus confluens, and Tityus martinpaechi, or in bivalent-like configuration in Rhopalurus rochai, Tityus bahiensis, Tityus confluens, Tityus fasciolatus, and Tityus paraguayensis. In the species examined, the 45S rDNA sites colocalized with constitutive heterochromatin regions. In light of the high chromosome variability and maintenance of number and terminal position of 45S rDNA sites in buthids, the heterochromatin may act to conserve the integrity of the ribosomal genes.

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