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1.
Mol Biol Evol ; 38(6): 2446-2467, 2021 05 19.
Article in English | MEDLINE | ID: mdl-33565584

ABSTRACT

Long-branch attraction is a systematic artifact that results in erroneous groupings of fast-evolving taxa. The combination of short, deep internodes in tandem with long-branch attraction artifacts has produced empirically intractable parts of the Tree of Life. One such group is the arthropod subphylum Chelicerata, whose backbone phylogeny has remained unstable despite improvements in phylogenetic methods and genome-scale data sets. Pseudoscorpion placement is particularly variable across data sets and analytical frameworks, with this group either clustering with other long-branch orders or with Arachnopulmonata (scorpions and tetrapulmonates). To surmount long-branch attraction, we investigated the effect of taxonomic sampling via sequential deletion of basally branching pseudoscorpion superfamilies, as well as varying gene occupancy thresholds in supermatrices. We show that concatenated supermatrices and coalescent-based summary species tree approaches support a sister group relationship of pseudoscorpions and scorpions, when more of the basally branching taxa are sampled. Matrix completeness had demonstrably less influence on tree topology. As an external arbiter of phylogenetic placement, we leveraged the recent discovery of an ancient genome duplication in the common ancestor of Arachnopulmonata as a litmus test for competing hypotheses of pseudoscorpion relationships. We generated a high-quality developmental transcriptome and the first genome for pseudoscorpions to assess the incidence of arachnopulmonate-specific duplications (e.g., homeobox genes and miRNAs). Our results support the inclusion of pseudoscorpions in Arachnopulmonata (new definition), as the sister group of scorpions. Panscorpiones (new name) is proposed for the clade uniting Scorpiones and Pseudoscorpiones.


Subject(s)
Phylogeny , Scorpions/classification , Animals , Female , Gene Duplication , Genes, Homeobox , Male , Scorpions/genetics
2.
Cladistics ; 37(2): 109-161, 2021 04.
Article in English | MEDLINE | ID: mdl-34478184

ABSTRACT

Asian forest scorpions (Scorpionidae Latreille, 1802: Heterometrinae Simon, 1879) are distributed across South and Southeast Asia. All are fossorial, constructing burrows under stones or in open ground, in habitats differing in precipitation and vegetation cover, from rainforests and tropical deciduous forests to savanna and scrubland. The systematics of these scorpions has long been confused due to bad taxonomy and the absence of a phylogenetic framework. Although the monophyly of the group was previously confirmed as part of broader phylogenetic analyses based on exemplar species, the only quantitative analysis of species-level variation to date was based on overall similarity. This contribution presents the first species-level phylogenetic analysis of Asian Scorpionidae, based on 186 morphological characters and 4188 aligned base-pairs of DNA sequence data from two nuclear and three mitochondrial loci for 132 terminals including all 41 ingroup species and four outgroup species. Simultaneous analyses of the morphological and molecular datasets with parsimony, Maximum Likelihood and Bayesian Inference provided the framework for a revised classification presented elsewhere. In order to understand how adaptation following dispersal into new habitats has driven the morphological diversification of Asian forest scorpions, species were scored for 10 characters concerning morphology and burrow architecture, which contributed to an ensemble index of adaptation to habitat aridity. Species were classified into three ecomorphotypes based on the index, and ancestral state reconstruction of ecomorphotypes performed on the phylogeny. A pattern was recovered in which lineages and species occurring in different habitats on a continuum from wet (evergreen forest) to dry (savanna, scrubland) exhibited characters presumed to be adaptive and hence responsible for driving scorpion diversification.


Subject(s)
Scorpions/classification , Animals , Forests , Phylogeny , Phylogeography , RNA, Ribosomal/chemistry , RNA, Ribosomal/genetics , Scorpions/anatomy & histology , Scorpions/genetics
3.
Zoolog Sci ; 38(1): 36-44, 2021 Feb.
Article in English | MEDLINE | ID: mdl-33639716

ABSTRACT

Southern Africa has a diverse endemic scorpion fauna, but a paucity of information currently confounds conservation of the group. Phylogeographic approaches represent a useful tool to identify the patterns and processes which underpin scorpion diversity, but these studies are lacking for southern African species. Among southern African scorpions, the semi-lithophilous Opistophthalmus pallipes has strict habitat requirements, and a distribution historically subjected to profound environmental turnover. As such, the species offers a model system to investigate the interplay between intrinsic and extrinsic factors as drivers of diversity and endemism. To investigate spatial genetic patterns within O. pallipes and the possible drivers thereof, the current study combines mitochondrial DNA and ecological information under a phylogeographic approach. The species is characterized by several genetically discrete and divergent populations. The factors which shape these genetic patterns appear to be both intrinsically (ecological specificity) and extrinsically (landscape structure and ecogeographic conditions) influenced, with major divergences corresponding to periods of profound environmental changes. Taken together, the findings of this study provide evidence of spatial genetic isolation and genetic diversity within a stenotopic southern African scorpion species. These findings partly explain the staggering diversity and endemism in southern African scorpions, but further phylogeographic studies are necessary to propose conservation scenarios for this group.


Subject(s)
Phylogeography , Scorpions/classification , Scorpions/genetics , Africa, Southern , Animals , DNA, Mitochondrial , Ecosystem , Sequence Analysis, DNA
4.
Mol Phylogenet Evol ; 135: 22-30, 2019 06.
Article in English | MEDLINE | ID: mdl-30831272

ABSTRACT

The Neartic family Vaejovidae (Scorpiones: Chactoidea) has long been treated as a diverse and systematically cohesive group of scorpions, but its monophyly and relationship to other scorpion families have historically been questioned. Morphological data have supported its monophyly and a variety of phylogenetic placements within the superfamily Chactoidea. Recent phylogenomic analyses have instead recovered vaejovids as polyphyletic (albeit with minimal taxonomic sampling) and Chactoidea as paraphyletic. Here, we reexamined the monophyly and phylogenetic placement of the family Vaejovidae, sampling 17 new vaejovid libraries using high throughput transcriptomic sequencing. Our phylogenomic analyses revealed a previous misplacement of Smeringurus mesaensis. Regardless, we recovered Vaejovidae as diphyletic due to the placement of the enigmatic genus Uroctonus. The remaining vaejovids formed a clade that was strongly supported as the sister group of the superfamily Scorpionoidea, a placement insensitive to matrix completeness or concatenation vs. species tree approaches to inferring the tree topology. Chactoidea was invariably recovered as a paraphyletic group due to the nested placement of Scorpionoidea. As first steps to resolving the paraphyly of Chactoidea, we take the following systematic actions: (1) we establish the superfamily Superstitionoidea (new superfamily) to accommodate Superstitioniidae; (2) we restore Vaejovoidea (status revalidated) as a valid superfamily that excludes Uroctonus; and (3) we treat the families Caraboctonidae, Troglotayosicidae, and the subfamily Uroctoninae as incertae sedis with respect to superfamilial placement. Our systematic actions thus establish the monophyly of the presently redefined Chactoidea and Vaejovoidea.


Subject(s)
Phylogeny , Scorpions/classification , Scorpions/genetics , Animals , Likelihood Functions , Sequence Analysis, DNA
5.
Molecules ; 24(14)2019 Jul 23.
Article in English | MEDLINE | ID: mdl-31340554

ABSTRACT

Scorpions, a characteristic group of arthropods, are among the earliest diverging arachnids, dating back almost 440 million years. One of the many interesting aspects of scorpions is that they have venom arsenals for capturing prey and defending against predators, which may play a critical role in their evolutionary success. Unfortunately, however, scorpion envenomation represents a serious health problem in several countries, including Iran. Iran is acknowledged as an area with a high richness of scorpion species and families. The diversity of the scorpion fauna in Iran is the subject of this review, in which we report a total of 78 species and subspecies in 19 genera and four families. We also list some of the toxins or genes studied from five species, including Androctonus crassicauda, Hottentotta zagrosensis, Mesobuthus phillipsi, Odontobuthus doriae, and Hemiscorpius lepturus, in the Buthidae and Hemiscorpiidae families. Lastly, we review the diverse functions of typical toxins from the Iranian scorpion species, including their medical applications.


Subject(s)
Antimicrobial Cationic Peptides/chemistry , Antineoplastic Agents/chemistry , Arthropod Proteins/chemistry , Scorpion Venoms/chemistry , Scorpions/chemistry , Animals , Antimicrobial Cationic Peptides/biosynthesis , Antimicrobial Cationic Peptides/genetics , Antimicrobial Cationic Peptides/therapeutic use , Antineoplastic Agents/isolation & purification , Antineoplastic Agents/pharmacology , Arthropod Proteins/biosynthesis , Arthropod Proteins/genetics , Arthropod Proteins/therapeutic use , Drug Discovery/methods , Gene Expression , Humans , Ion Channels/agonists , Ion Channels/antagonists & inhibitors , Ion Channels/metabolism , Iran , Metalloproteases/biosynthesis , Metalloproteases/isolation & purification , Metalloproteases/toxicity , Phospholipases A2/biosynthesis , Phospholipases A2/isolation & purification , Phospholipases A2/toxicity , Phylogeny , Scorpion Stings/physiopathology , Scorpion Venoms/biosynthesis , Scorpion Venoms/isolation & purification , Scorpions/classification , Scorpions/pathogenicity , Scorpions/physiology , Serine Proteinase Inhibitors/biosynthesis , Serine Proteinase Inhibitors/isolation & purification , Serine Proteinase Inhibitors/toxicity , Species Specificity
6.
Mol Phylogenet Evol ; 122: 37-45, 2018 05.
Article in English | MEDLINE | ID: mdl-29366829

ABSTRACT

The scorpion family Bothriuridae occupies a subset of landmasses formerly constituting East and West temperate Gondwana, but its relationship to other scorpion families is in question. Whereas morphological data have strongly supported a sister group relationship of Bothriuridae and the superfamily Scorpionoidea, a recent phylogenomic analysis recovered a basal placement of bothriurids within Iurida, albeit sampling only a single exemplar. Here we reexamined the phylogenetic placement of the family Bothriuridae, sampling six bothriurid exemplars representing both East and West Gondwana, using transcriptomic data. Our results demonstrate that the sister group relationship of Bothriuridae to the clade ("Chactoidea" + Scorpionoidea) is supported by the inclusion of additional bothriurid taxa, and that this placement is insensitive to matrix completeness or partitioning by evolutionary rate. We also estimated divergence times within the order Scorpiones using multiple fossil calibrations, to infer whether the family Bothriuridae is sufficiently old to be characterized as a true Gondwanan lineage. We show that scorpions underwent ancient diversification between the Devonian and early Carboniferous. The age interval of the bothriurids sampled (a derived group that excludes exemplars from South Africa) spans the timing of breakup of temperate Gondwana.


Subject(s)
Scorpions/classification , Animals , Bayes Theorem , Biodiversity , Biological Evolution , Fossils , Genetic Loci , Phylogeny , Scorpions/genetics
7.
Mol Phylogenet Evol ; 110: 39-49, 2017 05.
Article in English | MEDLINE | ID: mdl-28259729

ABSTRACT

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.


Subject(s)
Phylogeny , Scorpions/classification , Animals , Geography , South America , Species Specificity , Time Factors
8.
Pediatr Emerg Care ; 33(6): 405-408, 2017 Jun.
Article in English | MEDLINE | ID: mdl-26535779

ABSTRACT

OBJECTIVE: Scorpion stings are a major public health problem in many countries, particularly in pediatrics. Children are more susceptible to severe clinical manifestations of envenomation. The aim of this study is to determine the epidemiological and clinical characteristics of pediatric scorpionism in Hormozgan province of Iran during 2012. METHOD: This was a cross-sectional study being conducted during 2010 in Hormozgan, the southern province of Iran. We included 350 patients admitted to emergency unit of the hospitals of 8 cities of Hormozgan with impression of scorpion envenomation. The clinical and epidemiological characteristics as well as the treatment and outcome were recorded. RESULTS: The prevalence rate of pediatric scorpion stings in the province was 1.8 in 1000 children. The mean age of the patients was 5.75 ± 4.54 (range, 1-18) years. There were 208 (59.5%) boys and 142 (40.5%) girls among the patients. The most common site of sting was sole to knee in 94 (26.8%) followed by hand in 61 (17.4%) and fingers in 47 (13.4%). The most common presenting symptom was vomiting in 236 (67.4%) followed by localized pain in 131 (37.3%), erythema in 120 (34.2%), and edema in 119 (33.9%). The highest and lowest frequency occurred in July (17.7%) and January (3.2%), respectively. Nocturnal envenomations (53.7%) were more common than diurnal (46.3%). Most of scorpionism were mild (83.4%) that all evolved to cure, without any deaths. CONCLUSIONS: The results demonstrate the pediatric scorpionism is a public health problem in Hormozgan province of Iran, and special attention should be paid to prevention and treatment.


Subject(s)
Bites and Stings/diagnosis , Bites and Stings/epidemiology , Scorpion Stings/diagnosis , Scorpion Stings/epidemiology , Scorpions/classification , Animals , Antivenins/therapeutic use , Bites and Stings/complications , Bites and Stings/drug therapy , Child , Child, Preschool , Cross-Sectional Studies , Emergency Service, Hospital/statistics & numerical data , Female , Hospitalization/statistics & numerical data , Humans , Infant , Iran/epidemiology , Male , Prevalence , Scorpion Stings/complications , Scorpion Stings/drug therapy , Scorpions/physiology , Seasons , Treatment Outcome
9.
BMC Evol Biol ; 16: 72, 2016 Apr 07.
Article in English | MEDLINE | ID: mdl-27056633

ABSTRACT

BACKGROUND: Paleozoic scorpions (Arachnida: Scorpiones) have been widely documented from the Carboniferous Period; which hosts a remarkable assemblage of more than sixty species including both putative stem- and crown-group fossils. By contrast the succeeding Permian Period is almost completely devoid of records, which are currently restricted to a trace fossil from the early Permian of New Mexico, USA and some limb fragments from the late Permian of the Vologda Region, Russia. RESULTS: ?Opsieobuthus tungeri sp. nov. from the Petrified Forest of Chemnitz, Germany represents the first complete body fossils of scorpions from the Permian. Explosive volcanism preserved these remarkable specimens in situ as part of the palaeosol horizon and bedrock of the Petrified Forest, immediately beneath the Zeisigwald tuff horizon. This dates to the early Permian (Sakmarian) or ca. 291 Ma. Intriguingly, the specimens were obtained from a palaeosol horizon with a compacted network of different-sized woody roots and thus have been preserved in situ in their likely life position, even within their original burrows. Differences in the structure of the comb-like pectines in the two fossils offer evidence for sexual dimorphism, and permit further inferences about the ecology and perhaps even the reproductive biology of these animals. CONCLUSIONS: As putative members of a Coal Measures genus, these fossils suggest that at least some Carboniferous scorpion lineages extended their range further into the Permian. This contributes towards a picture of scorpion evolution in which both basal and derived (orthostern) forms coexisted for quite some time; probably from the end of the Carboniferous through to at least the mid Triassic.


Subject(s)
Biological Evolution , Scorpions/anatomy & histology , Scorpions/genetics , Animals , Ecology , Forests , Fossils , Germany , Scorpions/classification , Scorpions/physiology
10.
Mol Ecol ; 25(15): 3731-51, 2016 Aug.
Article in English | MEDLINE | ID: mdl-27238387

ABSTRACT

The California Floristic Province (CFP) in western North America is a globally significant biodiversity hotspot. Elucidating patterns of endemism and the historical drivers of this diversity has been an important challenge of comparative phylogeography for over two decades. We generated phylogenomic data using ddRADseq to examine genetic structure in Uroctonus forest scorpions, an ecologically restricted and dispersal-limited organism widely distributed across the CFP north to the Columbia River. We coupled our genetic data with species distribution models (SDMs) to determine climatically suitable areas for Uroctonus both now and during the Last Glacial Maximum. Based on our analyses, Uroctonus is composed of two major genetic groups that likely diverged over 2 million years ago. Each of these groups itself contains numerous genetic groups that reveal a pattern of vicariance and microendemism across the CFP. Migration rates among these populations are low. SDMs suggest forest scorpion habitat has remained relatively stable over the last 21 000 years, consistent with the genetic data. Our results suggest tectonic plate rafting, mountain uplift, river drainage formation and climate-induced habitat fragmentation have all likely played a role in the diversification of Uroctonus. The intricate pattern of genetic fragmentation revealed across a temporal continuum highlights the potential of low-dispersing species to shed light on small-scale patterns of biodiversity and the underlying processes that have generated this diversity in biodiversity hotspots.


Subject(s)
Biological Evolution , Genetics, Population , Phylogeny , Scorpions/genetics , Animals , California , Forests , Genomics , Scorpions/classification
11.
Naturwissenschaften ; 103(3-4): 19, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26879963

ABSTRACT

A fossil palpigrade is described and figured from mid-Cretaceous (Cenomanian) amber from northern Myanmar. Electrokoenenia yaksha Engel and Huang, gen. n. et sp. n., is the first Mesozoic fossil of its order and the only one known as an inclusion in amber, the only other fossil being a series of individuals encased in Pliocene onyx marble and 94-97 million years younger than E. yaksha. The genus is distinguished from other members of the order but is remarkably consistent in observable morphological details when compared to extant relatives, likely reflecting a consistent microhabitat and biological preferences over the last 100 million years.


Subject(s)
Amber , Fossils , Scorpions/anatomy & histology , Scorpions/classification , Animals , Myanmar , Species Specificity
12.
An Acad Bras Cienc ; 88 Suppl 1: 665-75, 2016.
Article in English | MEDLINE | ID: mdl-27142547

ABSTRACT

Scorpions belonging to the Tityus genus are of medical interest in Brazil. Among them, Tityus stigmurus is the main scorpion responsible for stings in the Northeast region. After a sting, the scorpion venom distributes rapidly to the organs, reaching the kidneys quickly. However, there are few studies concerning the renal pathophysiology of scorpion poisoning. In this study, we evaluated the effects of T. stigmurus venom (TsV) on renal parameters in isolated rat kidneys. Wistar rats (n = 6), weighing 250-300 g, were perfused with Krebs-Henseleit solution containing 6 g/100 mL bovine serum albumin. TsV at 0.3 and 1.0 µg/mL was tested, and the effects on perfusion pressure (PP), renal vascular resistance (RVR), urinary flow (UF), glomerular filtration rate (GFR), and electrolyte excretion were analyzed. Effects were observed only at TsV concentration of 1.0 µg/mL, which increased PP (controlPP40' = 92.7 ± 1.95; TsVPP40' = 182.0 ± 4.70* mmHg, *p < 0.05), RVR (controlRVR40' = 3.28 ± 0.23 mmHg; TstRVR40' = 6.76 ± 0.45* mmHg, *p < 0.05), UF (controlUF50' = 0.16 ± 0.04; TstUF50' = 0.60 ± 0.10* mL/g/min,*p < 0.05), GFR and electrolyte excretion, with histological changes that indicate renal tubular injury. In conclusion, T. stigmurus venom induces a transient increase in PP with tubular injury, both of which lead to an augmented electrolyte excretion.


Subject(s)
Kidney/drug effects , Scorpion Venoms/pharmacology , Scorpions , Animals , Brazil , Glomerular Filtration Rate/drug effects , Rats , Rats, Wistar , Scorpions/classification
13.
Proc Biol Sci ; 282(1804): 20142953, 2015 Apr 07.
Article in English | MEDLINE | ID: mdl-25716788

ABSTRACT

Scorpions represent an iconic lineage of arthropods, historically renowned for their unique bauplan, ancient fossil record and venom potency. Yet, higher level relationships of scorpions, based exclusively on morphology, remain virtually untested, and no multilocus molecular phylogeny has been deployed heretofore towards assessing the basal tree topology. We applied a phylogenomic assessment to resolve scorpion phylogeny, for the first time, to our knowledge, sampling extensive molecular sequence data from all superfamilies and examining basal relationships with up to 5025 genes. Analyses of supermatrices as well as species tree approaches converged upon a robust basal topology of scorpions that is entirely at odds with traditional systematics and controverts previous understanding of scorpion evolutionary history. All analyses unanimously support a single origin of katoikogenic development, a form of parental investment wherein embryos are nurtured by direct connections to the parent's digestive system. Based on the phylogeny obtained herein, we propose the following systematic emendations: Caraboctonidae is transferred to Chactoidea new superfamilial assignment: ; superfamily Bothriuroidea revalidated: is resurrected and Bothriuridae transferred therein; and Chaerilida and Pseudochactida are synonymized with Buthida new parvordinal synonymies: .


Subject(s)
Biological Evolution , Genome , Phylogeny , Scorpions/classification , Scorpions/genetics , Animals , Evolution, Molecular , Molecular Sequence Data , Scorpions/anatomy & histology , Sequence Analysis, DNA
14.
Mol Phylogenet Evol ; 91: 226-37, 2015 Oct.
Article in English | MEDLINE | ID: mdl-25987530

ABSTRACT

Scorpio Linnaeus, 1758 (family Scorpionidae Latreille, 1802) was considered monotypic for over a century, and comprised a single species, Scorpio maurus Linnaeus, 1758, with 19 subspecies, distributed from West Africa, throughout the Maghreb and the Middle East, to Iran. Two parapatric subspecies, Scorpio maurus fuscus (Ehrenberg, 1829) and Scorpio maurus palmatus (Ehrenberg, 1828), have long been recognized in the eastern Mediterranean region. We examined morphological variation, burrow architecture and genetic divergence among 39 populations across the distribution of the two subspecies to assess whether they are conspecific and, if not, how many species might be involved. Cuticle coloration, pedipalp chela digital carina condition, and selected measurements were recorded. Sixty burrows were excavated and examined for burrow structure and depth. A multilocus dataset comprising concatenated fragments of one nuclear (28S rDNA) and three mitochondrial (12S rDNA, 16S rDNA, Cytochrome c Oxidase Subunit I) loci, totaling ca. 2400 base-pairs, was produced for 41 individuals, and a single-locus dataset comprising 658 base-pairs of the COI locus for 156 individuals. Despite overlapping ranges in morphometric characters of pedipalp chela shape, the putative subspecies were easily distinguished by cuticle coloration and condition of the pedipalp chela digital carina, and were also found to differ significantly in burrow architecture and depth. Phylogeographical analyses of the COI and multilocus datasets recovered seven distinct clades. Separate analyses of mitochondrial sequences, and combined analyses of mitochondrial and nuclear sequences support most clades. The two major clades corresponded with the geographical distributions of S. m. fuscus and S. m. palmatus in the region. Specimens from these clades were genetically distinct, and exhibited different burrow structure in geographically-proximate localities, suggesting reproductive isolation. The palmatus clade included two distinct subclades of specimens from localities adjacent to the Dead Sea. Three other clades, comprising specimens from the most northeastern localities, were tentatively assigned to subspecies previously recorded in neighboring Jordan and Syria. The morphological, behavioral and genetic evidence supports previous suggestions that Scorpio maurus is a species complex and justifies the following taxonomic emendations: Scorpio fuscus (Ehrenberg, 1829), stat. nov.; Scorpio kruglovi Birula, 1910, stat. nov.; Scorpio palmatus (Ehrenberg, 1828), stat. nov.; Scorpio propinquus (Simon, 1872), stat. nov.


Subject(s)
Scorpions/classification , Animals , DNA, Mitochondrial/chemistry , Ecological and Environmental Phenomena , Middle East , Phylogeny , Phylogeography , Scorpions/anatomy & histology , Scorpions/genetics , Scorpions/physiology
15.
Biol Lett ; 11(1): 20140815, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25589484

ABSTRACT

One of the oldest known fossil scorpions, a new species from the mid-Silurian Eramosa Formation (430 myr) of Ontario, Canada, exhibits several surprising features. The depositional environment and associated biota indicate a marine habitat; however, the leg morphology of this scorpion, which has a short tarsus in common with all Recent scorpions, suggests that a key adaptation for terrestrial locomotion, the ability to support its weight on a subterminal 'foot', appeared remarkably early in the scorpion fossil record. Specimens are preserved intact and undisturbed in a splayed posture typical of moults rather than carcasses. We postulate that these animals were aquatic, but occasionally ventured into extremely shallow water, or onto a transient subaerially exposed surface while moulting, before returning to deeper water. Shed exuviae were preserved in situ by rapid overgrowth of bacterial biofilm.


Subject(s)
Fossils , Scorpions/anatomy & histology , Animals , Ecosystem , Extremities/anatomy & histology , Locomotion , Ontario , Scorpions/classification
16.
BMC Evol Biol ; 14: 9, 2014 Jan 16.
Article in English | MEDLINE | ID: mdl-24428910

ABSTRACT

BACKGROUND: Survival in microrefugia represents an important paradigm in phylogeography for explaining rapid postglacial re-colonization by species in temperate regions. Microrefugia may allow populations to persist in areas where the climatic conditions on the surface have become unfavourable. Caves generally contain stable microclimates and may represent microrefugia for species capable of exploiting both cave and surface habitats (troglophiles). We examine the phylogeography of the troglophilic North American vaejovid scorpion Pseudouroctonus reddelli using 1,993 base pairs of mitochondrial and nuclear DNA sequence data generated from 12 populations. We use (i) descriptive measures of genetic diversity and population genetics statistics, (ii) reconstructions of phylogeographical structure, spatial diffusion during diversification, and population sizes through time, and (iii) species distribution modelling to test predictions of the hypothesis that caves serve as microrefugia. We compare phylogeographical patterns in P. reddelli with other troglophilic species across the Edwards Plateau karst region of Texas. RESULTS: Results revealed high haplotype and nucleotide diversity and substantial phylogeographical structure, probably generated during the Pleistocene. Spatial diffusion occurred along the southern edge of the Edwards Plateau from multiple refugia along the Balcones Escarpment. There was little evidence for population and geographical expansion. Species distribution models predicted substantial reductions in suitable epigean habitat for P. reddelli at the Last Glacial Maximum (LGM). CONCLUSIONS: High genetic diversity, strong phylogeographical structure, diffusion from multiple refugia, and unfavourable climatic conditions at the LGM collectively support the hypothesis that caves served as microrefugia for P. reddelli. Similar patterns of genetic structure in P. reddelli and other troglophilic species across the Edwards Plateau karst region of Texas suggest that caves serving as microrefugia are important for the formation, maintenance, and future survival of troglophilic species in temperate karst regions.


Subject(s)
Caves , Scorpions/genetics , Animals , DNA, Mitochondrial/genetics , Ecosystem , Genetic Variation , Genetics, Population , Phylogeny , Phylogeography , Scorpions/classification , United States
17.
Cytogenet Genome Res ; 144(4): 341-7, 2014.
Article in English | MEDLINE | ID: mdl-25765094

ABSTRACT

Testicular cells of 4 buthid scorpions, Rhopalurus agamemnon (2n = 28), R. rochai (2n = 28), Tityus bahiensis (2n = 6), and T. fasciolatus (2n = 14), which show different types of chromosomal configurations in meiosis I, were subjected to cellular microspreading in order to (1) obtain knowledge about the organization and behavior of the synaptonemal complex (SC), and (2) acquire data about the mechanisms responsible for inter- and intraindividual chromosomal variation within Buthidae. Ultrastructural analysis of microspread nuclei revealed SCs with a well-preserved structure until late substages of prophase I, but did not detect kinetochore plates and recombination nodules. Pachytene cells of R. agamemnon, R. rochai and T. bahiensis exhibited single and unsynapsed axes continuous with totally synapsed SCs, indicating the occurrence of heterozygous chromosomal rearrangements. Although chromosome chains were not observed in T. fasciolatus, the presence of gaps and interlocks points out that this species also carries heterozygous rearrangements, involving a small chromosome segment. Especially in R. rochai, the cellular microspreading analysis was useful to clarify the origin of inter- and intraindividual variation in the number of bivalent-like elements and in the number of chromosomes involved in multivalent associations. It was found that more chromosomes were involved in rearrangements than previously established through investigations using light microscopy alone.


Subject(s)
Meiosis , Scorpions/cytology , Scorpions/genetics , Synaptonemal Complex/genetics , Animals , Chromosomes/genetics , Genetic Variation , Male , Scorpions/classification , Testis/ultrastructure
18.
Chromosome Res ; 21(2): 121-36, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23494776

ABSTRACT

In this study, we investigated the mitotic and meiotic chromosomes of 11 Buthidae scorpion species, belonging to three genera (Ananteris, Rhopalurus and Tityus), to obtain detailed knowledge regarding the mechanisms underlying the intraspecific and/or interspecific diversity of chromosome number and the origin of the complex chromosome associations observed during meiosis. The chromosomes of all species did not exhibit a localised centromere region and presented synaptic and achiasmatic behaviour during meiosis I. Spermatogonial and/or oogonial metaphase cells of these buthids showed diploid numbers range from 2n = 6 to 2n = 28. In most species, multivalent chromosome associations were observed in pachytene and postpachytene nuclei. Moreover, intraspecific variability associated with the presence or absence of chromosome chains and the number of chromosomes in the complex meiotic configurations was observed in some species of these three genera. Silver-impregnated cells revealed that the number and location of nucleolar organiser regions (NORs) remained unchanged despite extensive chromosome variation; notably, two NORs located on the terminal or subterminal chromosome regions were commonly observed for all species. C-banded and fluorochrome-stained cells showed that species with conspicuous blocks of heterochromatin exhibited the lowest rate of chromosomal rearrangement. Based on the investigation of mitotic and meiotic cells, we determined that the intraspecific variability occurred as a consequence of fission/fusion-type chromosomal rearrangements in Ananteris and Tityus species and reciprocal translocation in Rhopalurus species. Furthermore, we verified that individuals presenting the same diploid number differ in structural chromosome organisation, giving rise to intraspecific differences of chromosome association in meiotic cells (bivalent-like elements or chromosome chains).


Subject(s)
Karyotype , Scorpions/classification , Scorpions/genetics , Animals , Cell Nucleus/genetics , Centromere/genetics , Centromere/metabolism , Diploidy , Heterochromatin , Meiosis , Metaphase , Mitosis , Nucleolus Organizer Region , Pachytene Stage/genetics , Silver Staining , Translocation, Genetic
19.
Zootaxa ; 3785: 400-18, 2014 Apr 04.
Article in English | MEDLINE | ID: mdl-24872234

ABSTRACT

Brachistosternus paposo n. sp. and Brachistosternus barrigai n. sp. are described from Paposo, in the coastal transitional desert of northern Chile. Brachistosternus paposo n. sp. is closely related to Brachistosternus roigalsinai Ojanguren-Affilastro 2002, and B. barrigai n. sp. is closely related with Brachistosternus kamanchaca Ojanguren-Affilastro, Mattoni & Prendini 2007.


Subject(s)
Scorpions/anatomy & histology , Scorpions/classification , Animals , Biodiversity , Chile , Demography , Desert Climate , Female , Male
20.
Zhongguo Zhong Yao Za Zhi ; 39(12): 2208-11, 2014 Jun.
Article in Zh | MEDLINE | ID: mdl-25244746

ABSTRACT

In this study, the COI barcode was used to identify the Scolopendra medicinal materials and its adulterants in order to provide a new method for the identification of Scolopendra. Genomic DNA was extracted from the experimental samples. The COI sequences were amplified and sequenced bi-directionally. Sequence alignment and NJ tree construction was carried out by MEGA6.0 software. The results showed that the COI sequences can be obtained from all experimental samples. The average inter-specific K2P distance of Scolopendra was 0.222 and the minimum inter-specific distance was 0.190. All the Scolopendra subspinipes mutilans medicinal samples clustered into a clade in the NJ tree and can be distinguished from its adulterants. In a conclusion, COI can be used to correctly identify Scolopendra medicinal materials, and it will be a potential DNA barcode for identifying other animal medicinal materials.


Subject(s)
Arthropod Proteins/genetics , DNA Barcoding, Taxonomic/methods , Electron Transport Complex IV/genetics , Scorpions/classification , Scorpions/genetics , Animals , Drug Contamination/prevention & control , Medicine, Chinese Traditional , Molecular Sequence Data , Phylogeny , Quality Control , Scorpions/enzymology
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