High Chromosomal Reorganization and Presence of Microchromosomes in Chactidae Scorpions from the Brazilian Amazon.

Scorpions are of particular interest in cytogenomic studies, as they can present a high incidence of chromosomal rearrangements heterozygous in natural populations. In this study, we cytogenetically analyzed four species of Chactidae. In Brotheas, 2n = 40 was observed in Brotheas silvestris, 2n = 48 in Brotheas paraensis, and 2n = 50 (cytotype A) or 2n = 52 (cytotype B) among populations of Brotheas amazonicus. Our results showed a bimodal karyotype in Neochactas parvulus, 2n = 54, with microchromosomes and a concentration of constitutive heterochromatin in macrochromosomes. The 45S rDNA is located in only one pair of the karyotype, with different heteromorphisms of clusters of this rDNA in the cytotype B of B. amazonicus, with NOR-bearing chromosomes involved in multi-chromosomal associations during meiosis I. The U2 snDNA was mapped in the interstitial region of distinct karyotype pairs of three Chactidae species. Our results indicate the possible formation of cryptic species in B. amazonicus; the different 45S rDNA configurations in the genome of this species may result from amplification and degeneration. We suggest that the bimodal karyotype in N. parvulus results from fusion/fission events and that the unequal distribution of repetitive DNAs between macro and microchromosomes contributes to the maintenance of its asymmetry.

The morphology of mating plugs and its formation in scorpions: Implications for intersexual participation.

Mating plugs have been proposed as a mechanism that has evolved to avoid sperm competition. Their structure and composition vary across taxa and are related to the effectiveness of its function. This effectiveness could be related to different evolutionary interests of the sexes. Urophonius brachycentrus and Urophonius achalensis (Scorpiones, Bothriuridae) are highly suitable species to study mating plugs because both are monandrous species with specific morphological and physiological responses in the female's genitalia. Here, we analyze (a) the morphology and fine structure of the mating plugs of both species, (b) the site of production in males and the formation process of the mating plug, and (c) the changes that it undergoes over time in the female's reproductive tract. In both species, a complex mating plug obliterates the female's genital aperture and fills the genital atrium. We observed considerable interspecific variation in the mating plug morphology. A mating hemi-plug was found surrounding the capsular lobes of the hemispermatophore, which could have a mixed composition (involving portions of the hemispermatophore and glandular products). The glandular portion was transferred in a semi-solid state filling the female's genital atrium and then hardening. Changes that the plug undergoes in the female's genitalia (darkening and increase of the "distal" area of the plug) indicate a participation of the female to the formation of this type of plug. Our study provides new insights into the plugging phenomenon in scorpions, and we discussed the adaptive significance as a post-copulatory mechanism to avoid sperm competition.

p>Taxonomic revision of the Colombian Tityus (Archaeotityus) (Scorpiones, Buthidae) species: a morphological and morphometric approach, with a description of a new species.

We present a taxonomic revision of the Colombian Tityus (Archaeotityus) species based on morphological and morphometric evidence. We examined more than 385 specimens and evaluated new and previously used qualitative and quantitative morphological characters. We redescribe the Colombian species and present morphological characters for both sexes and an emended diagnosis for the subgenus Tityus (Archaeotityus). We describe a new species Tityus guane sp. nov. from Santander department, Colombia, Tityus betschi Lourenço 1992 is synonymized with Tityus parvulus Kraepelin, 1914, and Tityus wayuu Rojas-Runjaic Armas, 2007 is synonymized with Tityus tayrona Lourenço, 1991. We measured 186 specimens and performed a multivariate principal component analysis (PCA) for 34 selected morphometric ratios for each sex. We found that a few morphological ratios support species level distinctions within the Colombian species. We provide updated distributional maps with new records and an identification key for both sexes. Furthermore, we provide an updated checklist for the subgenus and a discussion about the character systems used within Tityus (Archaeotityus). The new morphological characters proposed and the traditional morphometry examined with a PCA are useful for studying Tityus (Archaeotityus) taxonomy.

Meiosis in the scorpion Tityus silvestris: new insights into achiasmatic chromosomes.

Achiasmatic male meiosis in scorpions is characterized by a high frequency of gaps, asynaptic regions and multivalent associations. Here, we performed an immunocytogenetic analysis to investigate recombination, and synapsis and chromatin-remodeling events during meiosis of the scorpion Tityus silvestris Our results demonstrate that the synaptonemal complex (SC) begins its organization in the zygotene stage and persists until metaphase I. The advancement of the synaptic process is related to the epigenetic modification histone H3 lysine 27 trimethylation (H3K27m3). The distribution and dynamics patterns of variant γH2AX and recombinase Rad51 during achiasmatic meiosis suggests formation and repair of DNA double-strand breaks (DSBs) during early stages of prophase I. The epigenetic modifications, histone H3 lysine 4 trimethylation (H3K4m3) and histone H3 lysine 9 acetylation (H3K9ac), showed a dispersed distribution along the bivalents, suggesting that transcriptional activity is maintained constitutively during prophase I. However, H3K9ac modifications are absent in constitutive heterochromatin carrying the 45S rDNA in pachytene and post-pachytene stages. Collectively, our data demonstrate that T. silvestris exhibits adaptations to the achiasmatic mode, and suggest that epigenetic modifications may act in the regulation of these mechanisms to favor the normal continuation of meiosis in this scorpion.

Five new scorpion species of genus Brachistosternus (Scorpiones: Bothriuridae) from the deserts of Chile and Peru, with comments about some poorly studied diagnostic characters of the genus.

Five new scorpion species of genus Brachistosternus of Chile and Peru are described. Brachistosternus gayi n. sp. is a high Andean species of north central Chile. Brachistosternus philippii n. sp. occurs near the coast of Antofagasta. Brachistosternus misti n. sp. occurs at intermediates altitudes of southern Peru. Brachistosternus contisuyu n. sp. occurs in Lomas formation in southern Peru. Brachistosternus anandrovestigia n. sp. occurs in coastal areas of southern Peru, and is the second known species of the genus without metasomal glands or androvestigia. Two diagnostic characters are discussed: the Internal Laminar Apophysis of the right hemispermatophore, and the sternum macrosetae.

Two new species of Bothriurus Peters, 1861 (Scorpiones, Bothriuridae) from Northeastern Brazil.

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.

A new species in the troglomorphic scorpion genus Troglotayosicus from Colombia, representing the northernmost known record for the genus (Scorpiones, Troglotayosicidae).

We describe a new scorpion species in the troglomorphic genus Troglotayosicus Lourenço, 1981 from Colombia. Troglotayosicus meijdeni sp. nov. inhabits the forest leaf litter at Rivera municipality, on the western slope of the Eastern Andes. The male of the new species remains unknown; however, this species can be distinguished from other species in the genus by the female (and juvenile) morphology. The type locality of T. meijdeni sp. nov. represents the northernmost known record for a population of Troglotayosicus, further extending the known limits of distribution of this genus, and shedding more light on the distributional range of this group of scorpions in northwestern South America. With this description, the number of known species of Troglotayosicus is raised to four; three of them are endogean species living in forested areas in the Andean region of Colombia, whereas one is a hypogean species from a cave in Ecuadorian Amazonia.

Karyotype diversity and chromosomal organization of repetitive DNA in Tityus obscurus (Scorpiones, Buthidae).

BACKGROUND: Holocentric chromosomes occur in approximately 750 species of eukaryotes. Among them, the genus Tityus (Scorpiones, Buthidae) has a labile karyotype that shows complex multivalent associations during male meiosis. Thus, taking advantage of the excellent model provided by the Buthidae scorpions, here we analyzed the chromosomal distribution of several repetitive DNA classes on the holocentric chromosomes of different populations of the species Tityus obscurus Gervais, 1843, highlighting their involvement in the karyotypic differences found among them. RESULTS: This species shows inter- and intrapopulational karyotype variation, with seven distinct cytotypes: A (2n = 16), B (2n = 14), C (2n = 13), D (2n = 13), E (2n = 12), F (2n = 12) and G (2n = 11). Furthermore, exhibits achiasmatic male meiosis and lacks heteromorphic sex chromosomes. Trivalent and quadrivalent meiotic associations were found in some cytotypes. In them, 45S rDNAs were found in the terminal portions of two pairs, while TTAGG repeats were found only at the end of the chromosomes. In the cytotype A (2n = 16), the U2 snRNA gene mapped to pair 1, while the H3 histone cluster and C 0 t-1 DNA fraction was terminally distributed on all pairs. Mariner transposons were found throughout the chromosomes, with the exception of one individual of cytotype A (2n = 16), in which it was concentrated in heterochromatic regions. CONCLUSIONS: Chromosomal variability found in T. obscurus are due to rearrangements of the type fusion/fission and reciprocal translocations in heterozygous. These karyotype differences follow a geographical pattern and may be contributing to reproductive isolation between populations analyzed. Our results also demonstrate high mobility of histone H3 genes. In contrast, other multigene families (45S rDNA and U2 snRNA) have conserved distribution among individuals. The accumulation of repetitive sequences in distal regions of T. obscurus chromosomes, suggests that end of chromosome are not covered by the kinetochore.

Dated phylogenetic studies of the southernmost American buthids (Scorpiones; Buthidae).

A dated molecular phylogeny of the southernmost American species of the family Buthidae, based on two nuclear and two mitochondrial genes, is presented. Based on this study, analyzed species of the subgenus Tityus (Archaeotityus) are neither sister to the remaining species of the genus Tityus, nor are they closely related to the New World microbuthids with decreasing neobothriotaxy. Analyzed species of the subgenus Tityus do not form a monophyletic group. Based on ancestral area estimation analyses, known geoclimatic events of the region and comparisons to the diversification processes of other epigean groups from the area, a generalized hypothesis about the patterns of historical colonization processes of the family Buthidae in southern South America is presented. Furthermore, for the first time, a Paleogene-African ingression route for the colonization of America by the family Buthidae is proposed as a plausible hypothesis.

Scorpions from the Mitaraka Massif in French Guiana. II. Description of a new species of Ananteris Thorell, 1891 (Scorpiones: Buthidae).

A new remarkable species belonging to the genus Ananteris Thorell, 1891 (Buthidae) is described from the Mitaraka Massif in French Guiana, a site located near the borders of French Guiana, Brazil, and Suriname. The description of this new species brings further evidence about the biogeographic patterns of distribution presented by most species of the genus Ananteris, which are highly endemic in most biogeographic realms of South America, including the Tepuys and Inselberg Massifs.

Scorpions from the Mitaraka Massif in French Guiana: Description of one new genus and species (Scorpiones: Chactidae).

A new genus and species, Spinochactas mitaraka gen. n., sp. n. (Chactidae) are described from the Mitaraka Massif in French Guiana, a site located near the borders of French Guiana, Brazil, and Suriname. The description of the new genus and species brings further evidence of the biogeographic pattern of distribution presented by some elements of the family Chactidae endemic to the Tepuys or to the Inselberg formations of South America.

Phylogeny, species delimitation and convergence in the South American bothriurid scorpion genus Brachistosternus Pocock 1893: Integrating morphology, nuclear and mitochondrial DNA.

A phylogenetic analysis of the scorpion genus Brachistosternus Pocock, 1893 (Bothriuridae Simon, 1880) is presented, based on a dataset including 41 of the 43 described species and five outgroups, 116 morphological characters and more than 4150 base-pairs of DNA sequence from the nuclear 18S rDNA and 28S rDNA gene loci, and the mitochondrial 12S rDNA, 16S rDNA, and Cytochrome c Oxidase Subunit I gene loci. Analyses conducted using parsimony, Maximum Likelihood and Bayesian Inference were largely congruent with high support for most clades. The results confirmed the monophyly of Brachistosternus, the nominal subgenus, and subgenus Ministernus Francke, 1985, as in previous analyses based only on morphology, but differed in several other respects. Species from the plains of the Atacama Desert diverged basally whereas the high altitude Andean species radiated from a more derived ancestor, presumably as a consequence of Andean uplift and associated changes in climate. Species limits were assessed among species that contain intraspecific variation (e.g., different morphs), are difficult to separate morphologically, and/or exhibit widespread or disjunct distributions. The extent of convergence in morphological adaptation to life on sandy substrata (psammophily) and the complexity of the male genitalia, or hemispermatophores, was investigated. Psammophily evolved on at least four independent occasions. The lobe regions of the hemispermatophore increased in complexity on three independent occasions, and decreased in complexity on another three independent occasions.

A new species of Auyantepuia González-Sponga, 1978 (Scorpiones, Chactidae) from French Guiana.

A new species of scorpion belonging to the genus Auyantepuia González-Sponga, 1978 (family Chactidae Pocock, 1893) is described on the basis of three specimens collected in a rainforest formation located in Saut Sabbat, South of Mana, French Guiana. This is the tenth species of the Guiano-Amazonian genus Auyantepuia, and the fifth reported from French Guiana.

The second confirmed record of the scorpion genus Chactas Gervais, 1844 (Scorpiones, Chactidae) from Ecuador with description of a new species from the Amazonian Province of Sucumbíos.

A new species, Chactas moreti sp. n., is described from Ecuadorian Amazonia. It can be distinguished from Chactas mahnerti Lourenço, 1995, the other known species of this genus from Ecuador by its smaller body size, distinct morphometric values, overall darker blackish-brown coloration, totally smooth vesicle, and a concave anterior margin of carapace. This is the second confirmed record of the genus Chactas Gervais from Ecuador. The geographical pattern of distribution of the genus is also discussed.

Impacto del cambio del uso del suelo sobre la diversidad de alacranes Arachnida scorpiones en el monte espinoso de la cuenca del río Motagua / Impact of land use change on the diversity of scaorpions (Arachnida: Scorpiones) in the thorn scrub of the Motagua River basin

Se evaluaron las diveridades alfa (riqueza de especies a nivel local), beta (recambio de especies entre sitios) y gamma (riqueza de especies en todo el paisaje) de alacranes en el monte espinoso de la cuenca del río Motagua, específicamente en loa porción comprendida entre El Rancho, (El Progreso) y Río Hondo (Zacapa), con el propósito de determinar el efecto que presenta el cambio de uso de suelo sobre la diversidad de especies y de establecer el grado de influencia de los componentes alfa y beta de la diversidad sobre la riqueza de especies del paisaje. Entre los meses de julio y agosto de 2008 se muestrearon ocho localidades del paisaje con distinto porcentaje de cambio de uso del suelo. Cada localidad fue muestreada dos veces durante el estudio. cada nuestreo consistió en reconocer cada sitio por 45 minutos (dos colectores a la vez) utilizando lámparas portátiles de luz ultravioleta para localizar a los alacranes. En todo el paisaje se registraron tres especies, pertenecientes a dos familias y dos géneros. Las especies fueron Centruroides margaritatus y C. schumidti, familia Buthidae y Diplocentrus sp., familia Scorpionidae...

Second record of Tityus bahiensis (Scorpiones, Buthidae) from Venezuela: epidemiological implications

This work reports the second record of the scorpion Tityus bahiensis Perty from Venezuela. The specimen was found alive in a wardrobe at a hotel resort in Margarita Island, northeastern Venezuela. Morphological characterization allowed its assignment to the Tityus bahiensis population inhabiting the southernmost area of the species' geographic range, e.g. the state of São Paulo in Brazil, northern Argentina and Paraguay. The fact that the only available Venezuelan antiscorpion (anti-Tityus discrepans) serum does not neutralize the effects of alpha- and beta-toxin from Tityus serrulatus venom (which resembles in composition that of T. bahiensis) constitutes a warning to local clinicians confronted with envenomations by noxious species transported to Venezuela from Brazil by human agency.

Second record of Tityus bahiensis (Scorpiones, Buthidae) from Venezuela: epidemiological implications

This work reports the second record of the scorpion Tityus bahiensis Perty from Venezuela. The specimen was found alive in a wardrobe at a hotel resort in Margarita Island, northeastern Venezuela. Morphological characterization allowed its assignment to the Tityus bahiensis population inhabiting the southernmost area of the species' geographic range, e.g. the state of São Paulo in Brazil, northern Argentina and Paraguay. The fact that the only available Venezuelan antiscorpion (anti-Tityus discrepans) serum does not neutralize the effects of alpha- and beta-toxin from Tityus serrulatus venom (which resembles in composition that of T. bahiensis) constitutes a warning to local clinicians confronted with envenomations by noxious species transported to Venezuela from Brazil by human agency.

Patrones de distribución de escorpiones de la región andina en el sur peruano

Se presenta la distribución geográfica de 24 especies de escorpiones (cinco géneros y tres familias) para el corredor andino en el sur del Perú. Se discuten algunos aspectos zoogeográficos de las especies involucradas (19 exclusivas del área de estudio), las que pueden reunirse en siete áreas escorpiológicas: Desierto costero, Lomas, Serranía esteparia, Puna, Queswa, Valles interandinos cálidos y Yungas. Las Lomas, Serranía esteparia y Queswa, presentan la mayor riqueza específica. Se analizan los patrones de distribución de las especies, que sugieren la presencia de tres componentes faunísticos en el sur del Perú: andino patagónico, amazónico y caribeño.

The geographical distribution of 24 scorpion species (five genera and three families) from the Andean corridor in southern Peru is provided. Some zoogeographic details of the implicated species are discussed (19 are exclusive from the area); these species are grouped into seven scorpiological areas: Desierto costero, Serranía esteparia, Puna, Queswa, Valles interandinos cálidos, and Yungas. The Lomas, Serranía esteparia and Queswa areas, are the areas with the most richness of species. The distribution patterns of species, which suggests the presence of three faunistic components in southern Peru: andean-patagonian, amazonian and caribbean, are analysed.

Uma nova espécie de Tityus C. L. Koch, 1836 (Scorpiones, Buthidae) do estado da Bahia, Brasil / x

Uma nova espécie do gênero Tityus C.L. Koch, 1836 (Scorpiones, Buthidae) é descrita dos municípios de Anagé (36'44''14S - 08'08''41W) e Poções (31'47''14S - 21'55''40W) no estado da Bahia, Brasil. Tityus aba n. sp pertence ao grupo Tityusbahiensis (Lourenço, 2002), caracterizado por espécies de tamanho que variam de cinco a sete cm de comprimento, com colorido variando do amarelo - palha ao marrom avermelhado e sem a lâmina mediana basal dilatada nas fêmeas. Neste grupo, aproxima-se das espécies do complexo Tityusstigmurus (Lourenço, 2001). A nova espécie é mais próxima de Tityus stigmurus (Thorell, 1876), Tityus martinpaechi Lourenço, 2001 e de Tityus melici Lourenço, 2003, distinguindo-se da primeira por apresentar o prossoma quase totalmente negro, maior número de dentes pectíneos e tamanho maior; da segunda por não apresentar manchas nos palpos e pernas, ausência de uma mancha negra de forma triangular sobre o prossoma e também tamanho maior, a da última pela ausência de manchas confluentes no mesossoma e de faixa longitudinal na face ventral dos segmentos de I a IV do metassoma. Tityus aba n.sp. apresenta indivíduos de médio a grande porte, medindo de 6,0 a 7,65 centímetros, de colorido geral castanho claro, com prossoma escuro quase negro e tergitos com três faixas escuras longitudinais, sendo uma mediana e duas laterais; carenas medianas dorsais dos segmentos II a IV com o último granulo maior, tornando-se espiniforme nos segmentos III e IV. Os machos apresentam os palpos mais delgados em relação às fêmeas e os segmentos IV e V do metassoma mais dilatados.

A new species of the genus Tityus C. L. Koch, 1836 (Scorpiones, Buthidae) from the state of Bahia, Brasil. A new species of the genus Tityus C.L.Koch, 1836 (Scorpiones, Buthidae) is described from Anagé (36°44'14"S - 08°08'41"W) and Poções (31°47'14"S - 21°55'40"W), state of Bahia, Brazil. Tityus aba n. sp. belongs to the Tityusbahiensis group Lourenço, 2002 characterized by medium sized specimens, ranging from five to seven cm in length, reddish-brown or brownish coloration patterns and basal middle lamellae of female pectines not dilatated in most species. Within the group, this species is close to the Tityus stigmurus complex and is more related to Tityusstigmurus (Thorell, 1876), Tityusmartinpaechi Lourenço, 2001 and Tityus melici Lourenço, 2003. T. aba n. sp. is distinguished from T. stigmurus by the color of the prossoma, which is almost black, by the higher number of pectinal teeth and by the larger body size. It is distinguished from T. martinpaechi mainly by the absence of dark spots on pedipalps and legs and also by the larger size of the specimens, and from T. melici , by the absence of dark confluent spots over the tergites and longitudinal strip between ventral keels of segments I to IV of the metasoma. Tityus aba n. sp. includes medium to large sized scorpions ranging from 6.0 to 7.65 cm, yellowish brown coloration pattern with an almost black carapace, with three longitudinal dark strips over the tergites, and with the dorsal medial keels of segment II to IV with a larger terminal granule that becomes spinoid on segments III and IV. The males are distinguished from the females by the slender pedipalps and more dilatated metasomal segments IV and V.

Descrição de uma nova espécie de Rhopalurus thorell, 1876 (scorpiones: Buthidae) do nordeste brasileiro / x

Rhopalurus guanambiensis n.sp. é descrita de Guanambi, Estado da Bahia, nordeste do Brasil. A nova espécie aproxima-se de R. lacrau Lourenço & Pinto-da-Rocha, 1997 (Itaeté, Estado da Bahia) por apresentar o mesmo número de séries de grânulos no dedo móvel da quela do pedipalpo, igual quantidade de carenas nos segmentos metasomais I, III, IV e V e pelo tamanho do corpo semelhante; aproxima-se de R. crassicauda Di Caporiacco, 1947 (Estado da Roraima) por apresentar o mesmo número de carenas nos segmentos metasomais I, II, IV e V, pela coloração mais escura dos dois últimos segmentos metasomais, que são dilatados e por apresentar aproximadamente o mesmo tamanho. Distingue-se de R. lacrau pela coloração diferente da carapaça, mesosoma e dos segmentos metasomais IV-V, maior número de dentes pectínios e pela presença de dez carenas no segmento metasomal II; de R.crassicauda, devido ao menor número de séries de grânulos no dedo móvel da quela do pedipalpo, maior número de dentes pectíneos, presença de oito carenas no segmento metasomal III e por apresentar um tubérculo subaculear acentuado no telson e carenas do segmento V do metasoma vestigiais. O macho de R. guanambiensis distingue-se da fêmea pela mão mais robusta e pela dilatação dos dois últimos segmentos do metasoma. A descrição desta espécie amplia para nove o número de espécies que ocorrem no Brasil.

Rhopalurus guanambiensis n. sp. is described from Guanambi, state of Bahia, northeastern Brazil. The new species is related to R. lacrau Lourenço & Pinto-da-Rocha, 1997 (Itaeté, state of Bahia) by having the same number of oblique rows of granules on the movable finger of the pedipalpal chela, same number of keels on metasomal segments I, III, IV, V and similar body size; it is related to R. crassicauda Di Caporiacco, 1947 (state of Roraima) by having the same number of keels on metasomal segments I, II, IV and V, last two metasomal segments darker colored and enlarged, and similar body size. It is distinguished from R. lacrau by the different color of the carapace, meso and metasomal segments IV-V, higher number of pectinal teeth and metasomal segment II with ten carinae; and from R. crassicauda by the lower number of oblique rows of granules on the movable finger of the pedipalp chela, metasomal segment III with eight carinae; segment V with vestigial keels and by the telson with a strong subaculear tubercle. The males of R. guanambiensis are distinguished from the female by having more robust pedipalp chelae and by the enlarged metasomal segments IV and V. This species raises the total number of species of the genus Rhopalurus in Brazil to nine.