Microallopatry caused strong diversification in Buthus scorpions (Scorpiones: Buthidae) in the Atlas Mountains (NW Africa)

The immense biodiversity of the Atlas Mountains in North Africa might be the result of high rates of microallopatry caused by mountain barriers surpassing 4000 meters leading to patchy habitat distributions. We test the influence of geographic structures on the phylogenetic patterns among Buthus scorpions using mtDNA sequences. We sampled 91 individuals of the genus Buthus from 51 locations scattered around the Atlas Mountains (Antiatlas, High Atlas, Middle Atlas and Jebel Sahro). We sequenced 452 bp of the Cytochrome Oxidase I gene which proved to be highly variable within and among Buthus species. Our phylogenetic analysis yielded 12 distinct genetic groups one of which comprised three subgroups mostly in accordance with the orographic structure of the mountain systems. Main clades overlap with each other, while subclades are distributed parapatrically. Geographic structures likely acted as long-term barriers among populations causing restriction of gene flow and allowing for strong genetic differentiation. Thus, genetic structure and geographical distribution of genetic (sub)clusters follow the classical theory of allopatric differentiation where distinct groups evolve without range overlap until reproductive isolation and ecological differentiation has built up. Philopatry and low dispersal ability of Buthus scorpions are the likely causes for the observed strong genetic differentiation at this small geographic scale.     

Evidence for recombination in scorpion mitochondrial DNA (Scorpiones: Buthidae)

There has been very little undisputed evidence for recombination in animal mitochondrial DNA (mtDNA) provided so far. Previous unpublished results suggestive of mtDNA recombination in the scorpion family Buthidae, together with cytological evidence for a unique mechanism of mitochondrial fusion in that family, prompted us to investigate this group in more details. First, we sequenced the complete mtDNA genome of Mesobuthus gibbosus, and chose two genes opposing each other (16S and coxI). We then sequenced 150 individuals from the natural populations of four species of Buthidae (Old World genera Buthus and Mesobuthus). We observed strong evidence for widespread recombination through highly significant negative correlations between linkage disequilibrium and physical distance in three out of four species. The evidence is further confirmed when using five other tests for recombination and by the presence of a high amount of homoplasy in phylogenetic trees.     

A fossil scorpion Tityus geratus new species (Scorpiones: Buthidae) from Dominican Amber

A fossil scorpion, Tityus geratus (Scorpioncs: Buthidae) n. sp., is described from Dominican amber. This is the third described amber Tityus sp. and the third Dominican amber scorpion. On the basis of the amber finds and available knowledge on the present distribution of Tityus spp. in the Antilles, the vicariance model of Caribbean biogeography can be evoked to best explain the present distribution of this genus.     

Parasitism of bark scorpion Centruroides exilicauda (Scorpiones: Buthidae) by entomopathogenic nematodes (Rhabditida: Steinernematidae; Heterorhabditidae)

In laboratory bioassays, Steinernema glaseri Steiner, Steinernema riobrave Cabanillas, Poinar & Raulston, Heterorhabditis bacteriophora Poinar, and Heterorhabditis marelatus Liu & Berry were capable of infecting and killing the bark scorpion, Centruroides exilicauda (Wood). Steinernema feltiae (Filipjev) and Steinernema carpocapsae (Weiser) failed to infect C. exilicauda at 22 degrees C. S. glaseri, H. marelatus, and H. bacteriophora caused significant mortality at 22 degrees C, indicating the potential role of these parasites as a biocontrol option. Efficacy of S. glaseri and H. bacteriophora was reduced in an assay conducted at 25 degrees C. Only S. glaseri was able to reproduce in the target host. Dissection of scorpions at the end of the experimental periods revealed inactive juvenile S. riobrave, H. marelatus, and H. bacteriophora nematodes. Both mermithid and oxyurid nematodes have been documented as nematode parasites of scorpions, but rhabditids have not been reported until now. Field studies are warranted to assess the usefulness of entomopathogenic nematodes as biocontrol agents of bark scorpions.     

Complements to the description of Tityus dedoslargos (Scorpiones: Buthidae)

The female of the Costarican scorpion Tityus dedoslargos Francke and Stockwell, 1987 is described for the first time and new data on its morphological variation and natural history are given. The female differs from the male mainly in having an enlarged basal median lamellae on the pectines, and lacking modified pedipalps. The species type locality relocated. This species is recorded from only two Costarican provinces: San Jose and Puntarenas.     

A new relictual buthid scorpion from the region of the Great Rift Valley in Kenya (Scorpiones,Buthidae)

A new genus and species of peri-Saharian buthid scorpion is described on the basis of single specimen collected in the Great Rift Valley, North of Kenya. This new scorpion taxon represents yet another endemic relict element for the faunas of the peri-Saharian regions. Comments are also included on the evolution of the Sahara and peri-Saharian regions and its possible consequences on the distribution of the extant scorpion fauna.     

Role of venom quantity in the feeding behavior of Jaguajir rochae (Scorpiones: Buthidae)

acta ethologica - Animal venom is composed of a complex mixture of protein-rich chemicals. Synthesis of animal venom incurs a high metabolic cost and is a prolonged process; consequently, animals...     

A new species of Tityus (Scorpiones: Buthidae) from Turimiquire, Venezuela

We describe a new species of Buthid scorpion, Tityus quirogae, from the Turimiquire mountains, eastern side of the La Costa range, Monagas and Sucre States, Venezuela. It is morphologically similar to T. nematochirus and T. meridanus. It differs from these species in the distribution of the dorsal femoral trichobothria and in the following combination of characters: (1) I caudal segment with two parallel ventral keels. Caudal segments II to IV with ventral keels that are double in the extremes of the segments and single in the middle, (2) noticeable sexual dimorphism, especially in pedipalp shape; the male chelae are markedly thin and long, (3) number of pectineous teeth (male: 18 in each pecten; female: 18 in the right pecten and 19 in the left one), and (4) number of denticle rows in the movable finger of the right chela (16 in both sexes). T. quirogae is the first species of this genus, in the Northeastern region of Venezuela, with thin and elongated pedipalps.     

Wernerius inyoensis, an elusive new scorpion from the Inyo Mountains of California (Scorpiones, Vaejovidae)

A new scorpion species is described from the Inyo Mountains of California (USA). The presence of a strong subaculear spine, along with other characters, places the new species within Wernerius, an incredibly rare genus that until now consisted of only two species. Wernerius inyoensissp. n. can be most easily distinguished from the other members of the genus by smaller adult size, femur and pedipalp dimensions, and differences in hemispermatophore morphology. Previous studies have suggested that the elusive nature of this genus may be attributed to low densities and sporadic surface activity. Herein, we provide another hypothesis, that Wernerius are primarily subterranean. Mitochondrial sequence data are provided for the holotype.     

A new species of the rare buthid scorpion genus Lissothus Vachon, 1948 from Central Algeria (Scorpiones,Buthidae)

Taxonomic considerations are given for the genus Lissothus Vachon, 1948 (Scorpiones, Buthidae). Two species are currently known, Lissothus bernardi Vachon, 1948 from Libya and Lissothus occidentalis Vachon, 1950 from Mauritania. In this contribution, a new species, Lissothus chaambi sp. n., is described from the desert of Central Algeria. The new species is most closely related to L. bernardi. The geographical distribution of the genus is discussed.     

Observations on the remarkable disrupted geographical distribution of the genus Microbuthus Kraepelin, 1898 in North Africa, with the description of a new species from Egypt (Scorpiones, Buthidae)

A disrupted Perisaharan pattern of distribution is confirmed for the species of the genus Microbuthus Kraepelin, 1898. A new species, Microbuthus flavorufus sp. n., is described from Egypt, raising the total number of known species of the genus to five.     

Ecological modeling and distribution analysis of digger scorpions: Odontobuthus doriae,Odonthubutus bidentatus (Scorpiones: Buthidae) and Scorpio maurus (Scorpiones: Scorpionidae) in Iran using the maximum entropy method

Prediction models are essential for the potential geographic distribution of scorpions, prevention of scorpion stings and diverse applications in conservation biology. There is limited information about habitat suitability and the factors affecting the distribution of Iranian digger scorpions. This study was undertaken to model the distribution of three types of digger scorpion in Iran, Odontobuthus doriae Thorell, Odonthubutus bidentatus Lourenco (Scorpiones: Buthidae) and Scorpio maurus Pocockin (Scorpiones: Scorpionidae), and investigate the factors affecting its distribution using the maximum entropy method. A total of 20 environmental and climate variables were used for modeling and evaluation of the ecological niche. The similarities and differences between the ecological overlap of the digger scorpions were evaluated using comparative environmental niche model (ENM Tools software). The results showed that the main factors for habitat suitability of O. doriae were soil type, mean temperature of the wettest quarter and slope. The variables for S. maurus were soil type, precipitation of the coldest quarter and slope. Annual temperature range, mean temperature of the driest quarter and land use had the greatest influence on the distribution of O. bidentatus. The ecological niches for O. doriae and O. bidentatus overlapped. The niche of these species differed from the niche of S. maurus. This approach could be helpful for the prediction of the potential distribution of three digger scorpion species and this model can be an effective for the promotion of health.

     

Phylogenetic analysis of the scorpion genus Brachistosternus (Arachnida, Scorpiones, Bothriuridae)

A phylogenetic analysis of the scorpion genus Brachistosternus Pocock (Bothriuridae) is presented. The analysis is based on a data set including 38 of the 41 described species of Brachistosternus plus eight outgroup representatives of seven additional bothriurid genera and one buthid, scored for 116 morphological characters. The cladistic analysis of this matrix under implied weighting results in four most parsimonious trees. The monophyly of genus Brachistosternus is well supported; its subgeneric subdivision is redefined: the subgenera Brachistosternus Pocock and Ministernus Francke are considered valid, whereas Leptosternus Maury is synonymized with Brachistosternus . Illustrations of diagnostic structures are provided. The hemispermatophores of Brachistosternus peruvianus Toledo-Piza and Brachistosternus pegnai Cekalovic are illustrated for the first time. A key to species of Brachistosternus and maps with the distribution of the subgenera and main groups of species are provided.     

Correction to: Ecological modeling and distribution analysis of digger scorpions: Odontobuthus doriae,Odontobuthus bidentatus (Scorpiones: Buthidae) and Scorpio maurus (Scorpiones: Scorpionidae) in Iran using the maximum entropy method

Applied Entomology and Zoology - The word “Odonthubutus” should be replaced with “Odontobuthus” throughout the article.     

Seasonal effects on cuticular permeability and epicuticular lipid composition inCentruroides sculpturatus ewing 1928 (Scorpiones: Buthidae)

Summary Third larval instar hemolymph of the fruitflyDrosophila hydei did not metabolize juvenile hormone (JH) at all developmental stages. In contrast, prepupal and pupal body fluid showed JH-esterase activity with a maximum at 4 h after puparium formation. In body wall and fat body of all developmental stages investigated, JH-metabolic activity was found. In both tissues JH catabolism was most active in the 120,000g supernatant and pellet. The 800g and 15,000g pellet showed a lower activity. In all subcellular fractions the JH-acid was identified as the predominant metabolite. There is evidence that JH-specific esterases are responsible for ester cleavage in the 120,000g supernatant. During mid and late third larval instar development in both body wall and fat body JH-esterase activity remains relatively constant.     

Structural and conformational analysis of scorpion (Buthus sindicus) hemocyanin using low resolution techniques

Blue oxygen binding protein hemocyanin from scorpion Buthus sindicus has been investigated using low resolution techniques. The native protein is a polymer of eight different types of subunits arranged in four cubic hexameric form (4x6-mers) as previously annotated using a combination of various types of chromatographic and electrophoretic techniques. In addition, both "top face" as well as the "side view" of the native assembly has also been identified from the negatively stained specimens using transmission electron microscopy confirming the overall structural features of arthropodan hemocyanins. These results are also supported from data obtained from another low resolution technique i.e. Small Angle X-ray scattering (SAXS). SAXS results under oxygenated and deoxygenated states represent a validation case for this technique with key conformational changes of Rg 88.0 --> 86.0 A; +/- 1% (Dmax 280.0 --> 290.0 A; +/- 2%), respectively suggesting that the oxygenated hemocyanin is longer then the deoxygenated hemocyanin by almost 2 A;. Likewise, active conformations of the purified structural and functional subunit Bsin1 under oxygenated and deoxygenated states also determined by SAXS measurements revealed a Rg value of 25.2 --> 25.7 A; +/- 1% (Dmax 75.0 --> 75.5 A; +/- 2%), respectively suggesting very little or no contribution of the individual subunit in the overall conformational change in the native assembly during molecular breathing. Preliminary molecular shapes for the oxy-molecules, calculated directly from the scattering profile-alone in a model-independent procedure, superimpose well on other closely related known three-dimensional structures of the same size. Structural and functional aspects of the native as well as purified subunit and the application of these low resolution techniques like transmission electron microscopy and Small Angle X-ray scattering have been discussed.