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The taxonomy of the South American genus Exomegas Gill 1883 has been unstable owing to the unknown status of the type specimen of its type species, Petromyzon macrostomus Burmeister 1868. Here the authors announce the finding of the holotype in the Museo Argentino de Ciencias Naturales "Bernardino Rivadavia" ichthyology collection. Whereas Exomegas type species is recognized based on its holotype, Exomegas gallegensis (Smitt 1901) new status is proposed. These preliminary results resolve a century-long taxonomic uncertainty and foster a nomenclatural arrangement for a Southern Hemisphere lamprey genus.

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Resumen Los arácnidos son un grupo megadiverso, en el cuál están las arañas y los escorpiones. Si bien todas las especies de ambos grupos tienen veneno, solo algunas son peligrosas para el ser humano, pudiendo causar hasta la muerte, y ocupan un lugar importante en las tradiciones de muchos pueblos. El objetivo del presente trabajo es conocer, mediante una encuesta, cuáles son los conocimientos de las personas sobre arañas y escorpiones y poner a prueba mitos y verdades mediante preguntas y repreguntas. Los resultados muestran un desconocimiento considerable en la población participante, especialmente con avanzado nivel educativo, que aceptan mitos por encima de los descubrimientos científicos verdaderos; además la respuesta entre varones y mujeres difiere de manera significativa en muchas preguntas. Estos resultados obligan a pensar políticas de educación que reviertan esos conocimientos erróneos basados en prejuicios o información de dudosa veracidad, por aquellos basados en la evidencia científica. Esto permitiría un manejo racional de estos grupos y así brindar medidas de prevención eficientes y pautas de acción si ocurriese un accidente.

Resumo Os aracnídeos são um grupo megadiverso, que inclui aranhas e escorpiões. Embora todas as espécies de ambos os grupos tenham veneno, só algumas são perigosas para o ser humano, podendo causar até a morte, e ocupam lugar importante nas tradições de muitas cidades. O objetivo do presente trabalho é conhecer, através de uma pesquisa, quais são os conhecimentos das pessoas sobre aranhas e escorpiões, e testar mitos e verdades por meio de perguntas e perguntas cruzadas. Os resultados mostram considerável desconhecimento por parte da população participante, em especial aquela com nível avançado de educação, que acredita em mitos mais frequentemente do que nas verdadeiras descobertas científicas; além disso, a resposta entre homens e mulheres difere significativamente em muitas questões. Esses resultados nos levam a pensar em políticas educacionais que revertam esses conhecimentos errôneos baseados em preconceitos ou informações de veracidade duvidosa, para aqueles baseados em evidências científicas. Isso permitiria um manejo racional dessas espécies, possibilitando medidas de prevenção eficientes e diretrizes para ação caso ocorra um acidente.

Abstract Arachnids are a megadiverse group, that include spiders and scorpions. Although the species of both groups are poisonous, only a few are dangerous to human beings, having the potential of causing death, and have an important place in the traditions of many cultures. This work aimed to evaluate, by means of a survey, the knowledge of the public about spiders and scorpions, and to test myths and truths through questions and cross-examinations. Results show a significant lack of awareness among the participants, especially those with higher level of education, who accept myths over true scientific discoveries; besides answers to many questions differ significantly between men and women. These results require the development of education policies that replace such erroneous knowledge based on prejudices or information of doubtful veracity, for scientific facts. This would allow a rational management of these species and thus provide efficient preventive measures and guidelines in case of accidents.

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Cytogenetic studies of the family Lycosidae (Arachnida: Araneae) are scarce. Less than 4% of the described species have been analyzed and the male haploid chromosome numbers ranged from 8+X1 X 2 to 13+X1 X 2. Species formerly classified as Lycosa were the most studied ones. Our aim in this work was to perform a comparative analysis of the meiosis in "Lycosa" erythrognatha Lucas, "Lycosa" pampeana Holmberg and Schizocosa malitiosa (Tullgren). We also compared male and female karyotypes and characterized the heterochromatin of "L." erythrognatha. The males of the three species had 2n = 22, n = 10+X1X2, all the chromosomes were telocentric and there was generally a single chiasma per bivalent. In "Lycosa" pampeana, which is described cytogenetically for the first time herein, the bivalents and sex chromosomes showed a clustered arrangement at prometaphase I. The comparison of the male/female karyotypes (2n = 22/24) of "Lycosa" erythrognatha revealed that the sex chromosomes were the largest of the complement and that the autosomes decreased gradually in size. The analysis of the amount, composition and distribution of heterochromatin with C-banding and staining with DAPI- and CMA3 - showed that "Lycosa" erythrognatha had little GC-rich heterochromatin in the pericentromeric region of all chromosomes. In addition, the actual occurrence of the genus Lycosa in the Southern Hemisphere is discussed.

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