Armas, de Luis F.
The buthid scorpions of the genus Centruroides are widely distributed in the Antillean area. They are also the most common scorpions in the majority of these islands. Nevertheless they remained almost forgotten until recently (STAHNKE 1970; ARMAS 1976, 1977, 1980, 1981, 1982; FRANCKE & SISSOM 1980).
SEBASTIAN ESTRADA GÓMEZ
Full Text Available We report the distribution of the Centruroides edwardsii (Gervais, 1843 in the Antioquia province, and the urban area of the capital, Medellín, Colombia, based in the material examined in the collection of the Universidad de Antioquia Serpentarium (SUA. A sexual dimporphism were established in C. edwardsii when a multidimensional analysis and using for the statistical significance the ANOSIM model were performed founding higher measurments in males. An important colony of this scorpion is reported in the central and nor-oriental zone of Medellín, aspect that is very relevant since this scorpion is clinically importance. The species distribution rank is also expanded from the sea level, up to 2200 m. a. s. l. DISTRIBUCIÓN DE Ccentruroides edwardsii (GERVAIS, 1843 EN EL DEPARTAMENTO EN ANTIOQUIA, COLOMBIA. Se reporta la distribución de Centruroides edwardsii (Gervais, 1843 para el departamento de Antioquia, y el área urbana de su capital político-administrativa, la ciudad de Medellín, Colombia, con base a material depositado en la colección del Serpentario de la Universidad de Antioquia (SUA. Se estableció dimorfismo sexual en C. edwardsii, mediante análisis de escalamiento multidimensional y el modelo ANOSIM, encontrando que los machos son más grandes que las hembras. Se reporta para el área zona centro y nor-oriental de Medellín una importante colonia de este escorpión, hecho de gran relecvanciarelevancia debido a la importancia clínica de este escorpión. Se amplía además el rango de distribución desde el nivel del mar hasta los 2200 m.s.n.m.
Full Text Available Scorpion systematics and taxonomy have recently shown a need for revision, partially due to insights from molecular techniques. Scorpion taxonomy has been difficult with morphological characters as disagreement exists among researchers with character choice for adequate species delimitation in taxonomic studies. Within the family Buthidae, species identification and delimitation is particularly difficult due to the morphological similarity among species and extensive intraspecific morphological diversity. The genus Centruroides in the western hemisphere is a prime example of the difficulty in untangling the taxonomic complexity within buthid scorpions. In this paper, we present phylogeographic, Ecological Niche Modeling, and morphometric analyses to further understand how population diversification may have produced morphological diversity in Centruroides vittatus (Say, 1821. We show that C. vittatus populations in the Big Bend and Trans-Pecos region of Texas, USA are phylogeographically distinct and may predate the Last Glacial Maximum (LGM. In addition, we suggest the extended isolation of Big Bend region populations may have created the C. vittatus variant once known as C. pantheriensis.
Nueva especie de alacrán del género Centruroides (Scorpiones, Buthidae del estado de Jalisco, México A new scorpion species of the genus Centruroides (Scorpiones, Buthidae from the state of Jalisco, Mexico
Javier Ponce Saavedra
Full Text Available Se describe Centruroides mascota sp. nov. de Mascota, Estado de Jalisco, México. Se hace una comparación con las especies morfológica y geográficamente más cercanas: C. elegans Thorell, C. hirsutipalpus Ponce y Francke, C. infamatus (Koch., C. ornatus Pocock y C. tecomanus Hoffmann. Es una especie de importancia médica que no se había recolectado o reconocido previamente.Centruroides mascota sp. nov. from Mascota, Jalisco, Mexico is described. The new species is compared with C. elegans Thorell, C. hirsutipalpus Ponce y Francke, C. infamatus (Koch., C. ornatus Pocock and C. tecomanus Hoffmann, which are morphologically and geographically nearest to it. This medically important species had not been collected or recognized previously
Descripción de una especie nueva de alacrán con importancia médica del género Centruroides (Scorpiones: Buthidae del estado de Colima, México Description of a new species of scorpion of medical importance of the genus Centruroides (Scorpiones: Buthidae from the state of Colima, Mexico
Full Text Available Se describe Centruroides hirsutipalpus sp. nov. de la región de Minatitlán, Colima. Se compara con las especies morfológica y geográficamente más cercanas, C. elegans Thorell y C. tecomanus Hoffmann y con otras especies "rayadas" de Centruroides del centro-occidente de México. Es ésta una especie con importancia médica que no se había recolectado previamente.Centruroides hirsutipalpus sp. nov. from the region of Minatitlán, Colima, Mexico is described. The new species is compared with C. elegans Thorell and C. tecomanus Hoffmann, which are morphologically and geographically closely related. Comparisons with other species of "striped" Centruroides from central and western Mexico are included. This medically important species had not been collected previously.
Full Text Available We report the first description studies, partial characterization, and intraspecific difference of Centruroides edwardsii, Gervais 1843, venom. C. edwardsii from two Colombian regions (Antioquia and Tolima were evaluated. Both venoms showed hemolytic activity, possibly dependent of enzymatic active phospholipases, and neither coagulant nor proteolytic activities were observed. Venom electrophoretic profile showed significant differences between C. edwardsii venom from both regions. A high concentration of proteins with molecular masses between 31 kDa and 97.4 kDa, and an important concentration close or below 14.4 kDa were detected. RP-HPLC retention times between 38.2 min and 42.1 min, showed bands close to 14.4 kDa, which may correspond to phospholipases. RP-HPLC venom profile showed a well conserved region in both venoms between 7 and 17 min, after this, significant differences were detected. From Tolima region venom, 50 well-defined peaks were detected, while in the Antioquia region venom, 55 well-defined peaks were detected. Larvicidal activity was only detected in the C. edwardsii venom from Antioquia. No antimicrobial activity was observed using complete venom or RP-HPLC collected fractions of both venoms. Lethally activity (carried out on female albino swiss mice was detected at doses over 19.2 mg/kg of crude venom. Toxic effects included distress, excitability, eye irritation and secretions, hyperventilation, ataxia, paralysis, and salivation.
Ricardo Antônio Lobo
Full Text Available Describes the case of a 6-year-old girl who was stung by a Centruroides testaceus, a scorpion native to the Lesser Antilles, in the Guarulhos International Airport, São Paulo, Brazil, as she disembarked from a flight coming from the Caribbean. The patient presented only local symptoms (a small area of erythema and pain at the sting site, which were resolved after a few hours with analgesics, without the need for antivenom. Physicians who treat patients stung by scorpions should be alert to the possibility of such accidents being caused by non native species, especially those cases that occur near airports or ports.
Miller, D W; Jones, A D; Goldston, J S; Rowe, M P; Rowe, A H
Studies of venom variability have advanced from describing the mechanisms of action and relative potency of medically important toxins to understanding the ecological and evolutionary causes of the variability itself. While most studies have focused on differences in venoms among taxa, populations, or age-classes, there may be intersexual effects as well. Striped bark scorpions (Centruroides vittatus) provide a good model for examining sex differences in venom composition and efficacy, as this species exhibits dramatic sexual dimorphism in both size and defensive behavior; when threatened by an enemy, larger, slower females stand and fight while smaller, fleeter males prefer to run. We here add evidence suggesting that male and female C. vittatus indeed have different defensive propensities; when threatened via an electrical stimulus, females were more likely to sting than were males. We reasoned that intersexual differences in defensive phenotypes would select for venoms with different functions in the two sexes; female venoms should be effective at predator deterrence, whereas male venoms, less utilized defensively, might be better suited to capturing prey or courting females. This rationale led to our predictions that females would inject more venom and/or possess more painful venom than males. We were wrong. While females do inject more venom than males in a defensive sting, females are also larger; when adjusted for body size, male and female C. vittatus commit equal masses of venom in a sting to a potential enemy. Additionally, house mice (Mus musculus) find an injection of male venom more irritating than an equal amount of female venom, likely because male venom contains more of the toxins that induce pain. Taken together, our results suggest that identifying the ultimate causes of venom variability will, as we move beyond adaptive storytelling, be hard-won. © The Author 2016. Published by Oxford University Press on behalf of the Society for Integrative and
Abd Rabo, H.A.M.
Unlike the amphibians, birds, mammals and reptiles, scorpions have no back bone, as they are invertebrates. Scorpions belong to the phylum arthropoda, their bodies are segmented and their legs are jointed. They belong to the class arachnida, because they have eight legs, two pedipalps, two chelicerae and a body composed of eighteen segments. The most important species of Buthidae family are Buthotus tamulus, Leiurus quinquestriatus, Androctonus crassicauda, Androctonus australis, Tityus serrulatus, and Centruroides suffusus (Minton, 2010). Scorpions are found in East Africa, Middle East, India, as well as Central and South America. Classification of scorpions from Africa and Middle East, has been summarized by Vachon, (1966). Unlike snakes, all scorpions are venomous. The venom is injected by means of a stinger found at the tip of the telson, the terminal structure of the tail. The smallest adults may range from approximately 2 to 3 cm and the largest between 15 to 25 cm (Bucherl, 1971). Scorpions have quite variable life spans. The age range appears to be approximately 4–25 years. Scorpions prefer to live in areas where the temperatures range from 20 °C to 37 °C, but may survive from freezing temperatures to the desert heat (Hadley, 1970; Hannah's et al., 2006). The death stalker (Leiurus quinquestriatus), is a member of the Buthidae family. It is also known as Palestine yellow scorpion, Omdurman scorpion, Israeli desert scorpion and numerous other colloquial names. To eliminate confusion, especially with potentially dangerous species, the scientific name is normally used to refer to them. The name Leiurus quinquestriatus roughly translates into English as f ive-striped smooth-tail . Other species of the genus Leiurus are often referred to as d eathstalkers a s well (Werness, 2004; Minton, 2010).
Una especie nueva de alacrán del género Centruroides de importancia médica (Scorpiones: Buthidae del estado de Guerrero, México A new scorpion species of medical importance of the genus Centruroides (Scorpiones: Buthidae from the state of Guerrero, Mexico
José Guadalupe Baldazo-Monsivaiz
Full Text Available Se describe Centruroides villegasi sp. nov. del municipio de Chilapa de Álvarez, Guerrero, que es la novena especie de Centruroides registrada para el estado. Se compara con C. limpidus (Karsch, 1879 por su parecido morfológico y por habitar la misma zona geográfica. Se compara también con C. balsasensis Ponce y Francke, 2004, C. meisei Hoffmann, 1938 y C. tecomanus Hoffmann, 1932, por pertenecer al grupo "alacranes rayados" (sensu Hoffmann, 1932, por su parecido morfológico y por su registro en Guerrero. Es una especie de importancia médica que no se había recolectado o reconocido previamente. Se incluye una lista de las especies de alacranes reconocidas para Guerrero, después de actualizar datos y hacer las correcciones necesarias a los registros históricos para el estado.Centruroides villegasi sp. nov. from the municipality of Chilapa de Álvarez, Guerrero, Mexico is described. It is the nineth species of Centruroides reported for this state. The new species is compared with C. limpidus (Karsch, 1879 which is morphologically similar and inhabits the same geographic zone. The species C. balsasensis Ponce and Francke, 2004, C. meisei Hoffmann, 1938, and C. tecomanus Hoffmann, 1932 are also compared because they are found in Guerrero and belong to the "striped scorpions" group (sensu Hoffmann, 1932, and therefore they are morphologically similar to the new species. It is a species of medical importance that had not been collected or recognized previously. A list of species of scorpions recorded for the state of Guerrero is included after the revision and correction of historical records.
Especie nueva de alacrán del género Centruroides (Scorpiones: Buthidae de la costa del estado de Jalisco, México A new scorpion species of the genus Centruroides (Scorpiones: Buthidae from the coast of the state of Jalisco, Mexico
Full Text Available Se describe Centruroides chamela sp. nov. de Chamela en el estado de Jalisco, México. Se compara con C. elegans (Thorell, especie con la que es simpátrida. También se compara con las especies morfológica y geográficamente más cercanas: C. mascota Ponce-Saavedra y Francke, C. hirsutipalpus Ponce-Saavedra y Francke y C. tecomanus Hoffmann. Además, con C. meisei Hoffmann, que habita en las costas de Guerrero, porque este taxón se había considerado como subespecie de C. elegans. En la comparación se incluyen C. infamatus (C.L. Koch y C. ornatus (Pocock, por ser especies "rayadas" registradas para el estado de Jalisco.Centruroides chamela sp. nov. from Chamela, Jalisco, Mexico is described. The new species is compared primarily with C. elegans Thorell, because both species are sympatric. It is also compared with C. mascota Ponce-Saavedra et Francke, C. hirsutipalpus Ponce-Saavedra et Francke and C. tecomanus Hoffmann which are morphologically and geographically nearest to the new species. Centruroides meisei Hoffmann, which inhabits the coast of Guerrero is compared because this species was previously classified as a subspecies of C. elegans. Finally, C. infamatus (C.L. Koch and C. ornatus (Pocock are included in the comparisons because they are also present in the state of Jalisco, and belong to the "striped" section of the genus.
Full Text Available Las proteínas del veneno del escorpión Centruroides margaritatus, fueron separadas mediante cromatografía de intercambio catiónico en CM-Sephadex C-25 con buffer acetato de amonio 0,05M a pH 7, a partir de 28,3 mg de veneno obtenidos de 52 ejemplares adultos capturados en la provincia de Zarumilla, Tumbes, norte del Perú. El perfil cromatográfico mostró la presencia de 9 picos de proteína y los ensayos de toxicidad han permitido identificar tres tipos de toxinas, cada una específica para crustáceos, insectos y roedores, respectivamente. Tanto en el veneno crudo como en las fracciones colectadas, no se encontró actividad de fosfolipasa ni actividad proteolítica. La PAGE-SDS del veneno crudo, muestra la presencia de una banda bastante notoria de aproximadamente 14 KDa, y otras dos muy tenues, de aproximadamente 45KDa, lo cual significa que la mayoría de proteínas de este veneno son de peso molecular igual o menor a 14KDa.
Olamendi-Portugal, Timoteo; Bartok, Adam; Zamudio-Zuñiga, Fernando; Balajthy, Andras; Becerril, Baltazar; Panyi, Gyorgy; Possani, Lourival D
Six new peptides were isolated from the venom of the Mexican scorpion Centruroides tecomanus; their primary structures were determined and the effects on ion channels were verified by patch-clamp experiments. Four are K(+)-channel blockers of the α-KTx family, containing 32 to 39 amino acid residues, cross-linked by three disulfide bonds. They all block Kv1.2 in nanomolar concentrations and show various degree of selectivity over Kv1.1, Kv1.3, Shaker and KCa3.1 channels. One peptide has 42 amino acids cross-linked by four disulfides; it blocks ERG-channels and belongs to the γ-KTx family. The sixth peptide has only 32 amino acid residues, three disulfide bonds and has no effect on the ion-channels assayed. It also does not have antimicrobial activity. Systematic numbers were assigned (time of elution on HPLC): α-KTx 10.4 (time 24.1); α-KTx 2.15 (time 26.2); α-KTx 2.16 (time 23.8); α-KTx 2.17 (time 26.7) and γ-KTx 1.9 (elution time 29.6). A partial proteomic analysis of the short chain basic peptides of this venom, which elutes on carboxy-methyl-cellulose column fractionation, is included. The pharmacological properties of the peptides described in this study may provide valuable tools for understanding the structure-function relationship of K(+) channel blocking scorpion toxins. Copyright © 2016 Elsevier Ltd. All rights reserved.
Farley Roger D
Full Text Available Abstract Background Near the end of the nineteenth century the hypothesis was presented for the homology of book lungs in arachnids and book gills in the horseshoe crab. Early studies with the light microscope showed that book gill lamellae are formed by outgrowth and possibly some invagination (infolding of hypodermis (epithelium from the posterior surface of opisthosomal limb buds. Scorpion book lungs are formed near the bilateral sites of earlier limb buds. Hypodermal invaginations in the ventral opisthosoma result in spiracles and sac-like cavities (atria. In early histological sections of embryo book lungs, widening of the atrial entrance of some lamellae (air channels, air sacs, saccules was interpreted as an indication of invagination as hypothesized for book gill lamellae. The hypodermal infolding was thought to produce the many rows of lamellar precursor cells anterior to the atrium. The ultrastructure of scorpion book lung development is compared herein with earlier investigations of book gill formation. Results In scorpion embryos, there is ingression (inward migration of atrial hypodermal cells rather than invagination or infolding of the atrial hypodermal layer. The ingressing cells proliferate and align in rows anterior to the atrium. Their apical-basal polarity results in primordial air channels among double rows of cells. The cuticular walls of the air channels are produced by secretion from the apical surfaces of the aligned cells. Since the precursor cells are in rows, their secreted product is also in rows (i.e., primordial air channels, saccules. For each double row of cells, their opposed basal surfaces are gradually separated by a hemolymph channel of increasing width. Conclusions The results from this and earlier studies show there are differences and similarities in the formation of book lung and book gill lamellae. The homology hypothesis for these respiratory organs is thus supported or not supported depending on which developmental features are emphasized. For both organs, when the epithelial cells are in position, their apical-basal polarity results in alternate page-like channels of hemolymph and air or water with outward directed hemolymph saccules for book gills and inward directed air saccules for book lungs.
Martínez-Zérega, Brenda E.; González-Solís, José L.
In this work we study the venom of two Centruroides scorpion species using Raman spectroscopy. The spectra analysis allows to determine the venoms chemical composition and to establish the main differences and similarities among the species. It is also shown that the use of Principal Component Analysis may help to tell apart between the scorpion species.
Otero, R; Navío, E; Céspedes, F A; Núñez, M J; Lozano, L; Moscoso, E R; Matallana, C; Arsuza, N B; García, J; Fernández, D; Rodas, J H; Rodríguez, O J; Zuleta, J E; Gómez, J P; Saldarriaga, M; Quintana, J C; Núñez, V; Cárdenas, S; Barona, J; Valderrama, R; Paz, N; Díaz, A; Rodríguez, O L; Martínez, M D; Maturana, R; Beltrán, L E; Mesa, M B; Paniagua, J; Flórez, E; Lourenço, W R
To determine clinical and epidemiological features of scorpion stings in two departments of Colombia, a descriptive study was performed in the hospitals of 10 towns from Antioquia (2 256 071 inhabitants) and five from Tolima (630 424 inhabitants). One hundred and twenty-nine cases were admitted during one year, 51 in Antioquia, 78 in Tolima and 41 were children less than 15 years old. Most stings (70.5%) occurred inside the house; 27.9% were on the hands and 26.4% on the feet. The scorpion species involved were Tityus pachyurus (51), Centruroides gracilis (31), T. fuehrmanni (29), T. asthenes (7) and Chactas spp. (1). In 10 cases the scorpion involved was not identified. Systemic envenoming signs (e.g. vomiting, tachypnea) were significantly more frequent in children than in adults (P < 0.05). Four children had hypertension, but none developed pulmonary oedema. One 3-year-old girl, stung by T. asthenes, had acute oedematous pancreatitis. Ninety-eight patients had mild envenoming. Moderate (27 patients) and severe (four patients) envenoming was significantly more frequent in children than in adults (P = 0.003; relative risk = 2.97). A pepsin-digested anti-Centruroides spp. antivenom was administered to 19 of 31 patients presenting systemic envenoming signs. No adverse reactions to antivenom were observed.
Schofield, R.; Lefevre, H.; Shaffer, M.
Energy-loss scanning transmission ion microscopy (ELSTIM or just STIM), PIXE and electron microprobe techniques are used to investigate certain minor element accumulations in a few spiders and scorpions. STIM and PIXE are used to survey the unsectioned specimens, while electron microprobe techniques are used for higher resolution investigations of several sections of the specimens. Concentration values measured using STIM and PIXE are found to be in satisfactory agreement with those measured using electron probe microanalysis. A garden spider Araneous diadematus is found to contain high concentrations of zinc in a thin layer near the surface of its fangs (reaching 23% of dry weight), and manganese in its marginal teeth (about 5% of dry weight). A wolf spider Alopecosa kochi is found to have similar concentrations of zinc in a layer near the surface of it's fang, and concentrations of manganese reaching 1.5% in a layer beneath the zinc containing layer. A scorpion Centruroides sp. is found to contain high concentrations of iron (reaching 8%) and zinc (reaching 24%) in the tips of teeth on the cheliceral fingers, and manganese (about 5%) in the stinger. The hypothesis that these elements simply harden the cuticle does not appear to explain their segregation patterns. (orig.)
Borges, Adolfo; Morales, Melva; Loor, Wilmer; Delgado, Miguel
The presence in rural areas of western Ecuador of scorpions in the genus Tityus capable of producing pediatric mortality is hereby evidenced. The medical significance of scorpions in Ecuador has been underestimated partly because of the clinically unimportant stings delivered by Centruroides margaritatus and Teuthraustes atramentarius, which have venom with low toxicity to vertebrates. Five intra-domiciliary cases of scorpion envenoming in victims aged between 1.9 and 16 years old, including one fatality, are reported from rural settings in forest areas of Chone (n = 2) and Flavio Alfaro (n = 3) counties, northern Manabí province, western Ecuador. Three cases were graded as Class II (moderate) and two in Class III (severe) envenoming. Manifestations showed characteristic autonomic nervous system hyper-stimulation and the fatality (a 1.9-year-old boy from Flavio Alfaro) was due to cardio-respiratory failure. Marked leukocytosis in four of the cases (21,800-31,800 cells/mm(3)), with notable neutrophilia (58-82%), suggests induction of a venom-mediated systemic inflammatory response-like syndrome. Specimens responsible for cases in Flavio Alfaro County, including the fatality, were classified as Tityus asthenes Pocock, accountable for severe scorpionism in Colombia. These findings demand implementation of control and therapeutic measures in affected areas in Ecuador, including evaluation of available scorpion antivenoms. Copyright © 2015 Elsevier Ltd. All rights reserved.
Schwager, Evelyn E; Sharma, Prashant P; Clarke, Thomas; Leite, Daniel J; Wierschin, Torsten; Pechmann, Matthias; Akiyama-Oda, Yasuko; Esposito, Lauren; Bechsgaard, Jesper; Bilde, Trine; Buffry, Alexandra D; Chao, Hsu; Dinh, Huyen; Doddapaneni, HarshaVardhan; Dugan, Shannon; Eibner, Cornelius; Extavour, Cassandra G; Funch, Peter; Garb, Jessica; Gonzalez, Luis B; Gonzalez, Vanessa L; Griffiths-Jones, Sam; Han, Yi; Hayashi, Cheryl; Hilbrant, Maarten; Hughes, Daniel S T; Janssen, Ralf; Lee, Sandra L; Maeso, Ignacio; Murali, Shwetha C; Muzny, Donna M; Nunes da Fonseca, Rodrigo; Paese, Christian L B; Qu, Jiaxin; Ronshaugen, Matthew; Schomburg, Christoph; Schönauer, Anna; Stollewerk, Angelika; Torres-Oliva, Montserrat; Turetzek, Natascha; Vanthournout, Bram; Werren, John H; Wolff, Carsten; Worley, Kim C; Bucher, Gregor; Gibbs, Richard A; Coddington, Jonathan; Oda, Hiroki; Stanke, Mario; Ayoub, Nadia A; Prpic, Nikola-Michael; Flot, Jean-François; Posnien, Nico; Richards, Stephen; McGregor, Alistair P
The duplication of genes can occur through various mechanisms and is thought to make a major contribution to the evolutionary diversification of organisms. There is increasing evidence for a large-scale duplication of genes in some chelicerate lineages including two rounds of whole genome duplication (WGD) in horseshoe crabs. To investigate this further, we sequenced and analyzed the genome of the common house spider Parasteatoda tepidariorum. We found pervasive duplication of both coding and non-coding genes in this spider, including two clusters of Hox genes. Analysis of synteny conservation across the P. tepidariorum genome suggests that there has been an ancient WGD in spiders. Comparison with the genomes of other chelicerates, including that of the newly sequenced bark scorpion Centruroides sculpturatus, suggests that this event occurred in the common ancestor of spiders and scorpions, and is probably independent of the WGDs in horseshoe crabs. Furthermore, characterization of the sequence and expression of the Hox paralogs in P. tepidariorum suggests that many have been subject to neo-functionalization and/or sub-functionalization since their duplication. Our results reveal that spiders and scorpions are likely the descendants of a polyploid ancestor that lived more than 450 MYA. Given the extensive morphological diversity and ecological adaptations found among these animals, rivaling those of vertebrates, our study of the ancient WGD event in Arachnopulmonata provides a new comparative platform to explore common and divergent evolutionary outcomes of polyploidization events across eukaryotes.
Full Text Available Scorpionism in the Americas occurs mainly in Mexico, northern South America and southeast Brazil. This article reviews the local scorpion fauna, available health statistics, and the literature to assess scorpionism in Central America. Notwithstanding its high toxicity in Mexico, most scorpion sting cases in Guatemala, Belize, El Salvador, Nicaragua, and Costa Rica are produced by species in the genus Centruroides that are only mildly toxic to humans despite the existence of ion channel-active toxins in their venoms. Regional morbidity is low with the exception of Panama, where an incidence of 52 cases per 100,000 inhabitants was recorded for 2007, with 28 deaths from 1998 to 2006. Taxa belonging to the genus Tityus (also present in the Atlantic coast of Costa Rica are responsible for fatalities in Panama, with Tityus pachyurus being the most important species medically. Most Tityus species inhabiting Panama are also found in northern South America from which they probably migrated upon closure of the Panamanian isthmus in the Miocene era. Incorporation of Panama as part of the northern South American endemic area of scorpionism is thereby suggested based on the incidence of these accidents and the geographical distribution of Panamanian Tityus species.
Morfometría geométrica en cinco especies de Buthidae y Scorpionidae (Arachnida: Scorpiones de Venezuela Geometric morphometrics in five species of Buthidae and Scorpionidae (Arachnida: Scorpiones from Venezuela
Walter Y. Bechara
Full Text Available En Venezuela, la escorpiofauna consta de 17 géneros y 202 especies. En algunos grupos la taxonomía no ha sido aclarada; por lo tanto, son necesarias investigaciones adicionales que contribuyan a mejorar el conocimiento sobre la identidad taxonómica y relaciones entre sus componentes. La morfometría geométrica es una herramienta que ha sido utilizada como apoyo a la sistemática en distintos organismos. El objetivo del presente trabajo fue analizar la conformación y tamaño isométrico en 5 especies de escorpiones. Se fotografiaron 266 individuos de 4 especies de Buthidae: Centruroides testaceus, Rhopalurus laticauda, Tityus clathratus y T. discrepans, y una de Scorpionidae: Tarsoporosus yustizi. Se registraron configuraciones de coordenadas (x,y en 5 estructuras a partir de puntos anatómicos de referencia (PAR y PAR deslizantes. Los resultados mostraron separación completa de las especies de Buthidae por medio de tricobotrias dorsales en la patela del pedipalpo, y una consistente separación en el nivel familiar en las estructuras restantes. Las placas delgadas permitieron la visualización de compresión horizontal del esternón en las especies de Buthidae y compresión vertical en la de Scorpionidae. Se determinó la similitud de coxas, quela y caparazón entre R. laticauda y C. testaceus. La disposición de tricobotrias y la conformación del esternón permitió la diferenciación entre T. discrepans y T. clathratus.The Venezuelan scorpionfauna comprises 17 genera and 202 species. In some taxa the taxonomy is unclear, and additional studies that contribute to the knowledge about taxonomic identity and relationships are necessary. Geometric morphometrics is a tool that has been used as support to the systematics in different organisms. The goal was to analize the isometric size and conformation in five scorpions species. We photographed 266 individuals of four speceis of Buthidae: Centruroides testaceus, Rhopalurus laticauda, Tityus
Background The monophyly of Mandibulata - the division of arthropods uniting pancrustaceans and myriapods - is consistent with several morphological characters, such as the presence of sensory appendages called antennae and the eponymous biting appendage, the mandible. Functional studies have demonstrated that the patterning of the mandible requires the activity of the Hox gene Deformed and the transcription factor cap-n-collar (cnc) in at least two holometabolous insects: the fruit fly Drosophila melanogaster and the beetle Tribolium castaneum. Expression patterns of cnc from two non-holometabolous insects and a millipede have suggested conservation of the labral and mandibular domains within Mandibulata. However, the activity of cnc is unknown in crustaceans and chelicerates, precluding understanding of a complete scenario for the evolution of patterning of this appendage within arthropods. To redress these lacunae, here we investigate the gene expression of the ortholog of cnc in Parhyale hawaiensis, a malacostracan crustacean, and two chelicerates: the harvestman Phalangium opilio, and the scorpion Centruroides sculpturatus. Results In the crustacean P. hawaiensis, the segmental expression of Ph-cnc is the same as that reported previously in hexapods and myriapods, with two distinct head domains in the labrum and the mandibular segment. In contrast, Po-cnc and Cs-cnc expression is not enriched in the labrum of either chelicerate, but instead is expressed at comparable levels in all appendages. In further contrast to mandibulate orthologs, the expression domain of Po-cnc posterior to the labrum is not confined within the expression domain of Po-Dfd. Conclusions Expression data from two chelicerate outgroup taxa suggest that the signature two-domain head expression pattern of cnc evolved at the base of Mandibulata. The observation of the archetypal labral and mandibular segment domains in a crustacean exemplar supports the synapomorphic nature of mandibulate cnc
Effects of Ionizing Radiation on Insects and Other Arthropods; Effet des rayonnements ionisants sur les insectes et autres arthropodes; Vozdejstvie ioniziruntsej radiatsii na nasekomykh i drugikh chlenistonogikh; Efectos de las radiaciones ionizantes sobre los insectos y otros artropodos
Stone, William E. [United States Department of Agriculture Laboratories, Mexico City, D.F (Mexico)
Research into the possible application of the radiation sterilization method of population suppression is now under way on a number of insects that attack man, animals and a variety of crops. These exploratory investigations have shown that ionizing irradiation will induce sterility but there is considerable variation in the amounts needed. The research also suggests that radiation damage may in some cases prevent application of the method to some insects. A frequent obstacle that must be overcome is lack of practical mass-rearing methods. Some insects also appeartobeso abundant that the use of the technique may not be feasible without first processing the infested area with other control measures to bring wild populations within reach. Despite these difficulties, when conditions are favourable, few other approaches to the control of pests are so potentially rewarding. The radiation sterilization method may also be thought of as a possible means of delaying development of infestation until crops are harvested. The present paper reports on the influence-of gamma radiation on the reproductive potential, sexual aggressiveness, vigour and longevity of the oriental fruit fly, Dacus dorsalis Hendel, the melon fly, Dacus cucurbitae Coq., the Mediterranean fruit fly, Ceratitis capitata Wied., the Mexican fruit fly, Anastrepha ludens Loew, and Anopheles quadrimaculatus Say, and results of practical field trials of the sterile-male release method of population suppression. Progress in the campaign to eradicate the screw-worm, Cochliomyia hominivora Cqrl., in the United States and in studies to develop vigorous genetically marked strains that will permit ready identifications of released sterile flies is reviewed. Results of irradiation research on six additional species that infest fruit, vegetable, field and forest crops, three that attack livestock, three that largely affect man, the effects of irradiation on the scorpion, Centruroides limpid us Karsch, and the Lone