The Caribbean slipper spurge
            Euphorbia tithymaloides
            : the first example of a ring species in plants

A ring species arises when a parental population expands around an area of unsuitable habitat in such a way that when the two fronts meet they behave as distinct species while still being connected through a series of intergrading populations. Ring species offer great possibilities for studying the forces causing species divergence (e.g. the nature of pre-zygotic or post-zygotic reproductive isolation) or helping to maintain species integrity (e.g. reinforcement). Yet, ring species are extremely rare, and have only been documented convincingly in animals. Here, we present phylogenetic analyses of two nuclear gene regions from the Caribbean slipper spurge ( Euphorbia tithymaloides ) species complex that provide evidence that this group forms a ring species. These data show that the species complex originated in the area where Mexico and Guatemala meet, and expanded around the Caribbean basin along two distinct fronts: one eastward through the Yucatan Peninsula and into the Greater Antilles (GA); one southeastward through northern South America and then northward to the Lesser Antilles and eastern GA. The two terminal forms co-occur in the Virgin Islands and appear to be morphologically and ecologically distinct. Thus, our results suggest that Euphorbia tithymaloides is the first compelling example of a ring species in plants.

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Veterinary Fusarioses within the United States

Journal of Clinical Microbiology ◽

10.1128/jcm.01607-16 ◽

2016 ◽

Vol 54 (11) ◽

pp. 2813-2819 ◽

Cited By ~ 21

Author(s):

Kerry O'Donnell ◽

Deanna A. Sutton ◽

Nathan Wiederhold ◽

Vincent A. R. G. Robert ◽

Pedro W. Crous ◽

...

Keyword(s):

United States ◽

Dna Sequence ◽

Species Complex ◽

Sequence Data ◽

Phylogenetic Analyses ◽

Distinct Species ◽

The United States ◽

Content Type ◽

Dna Sequence Data ◽

Species Complexes

Multilocus DNA sequence data were used to assess the genetic diversity and evolutionary relationships of 67Fusariumstrains from veterinary sources, most of which were from the United States. Molecular phylogenetic analyses revealed that the strains comprised 23 phylogenetically distinct species, all but two of which were previously known to infect humans, distributed among eight species complexes. The majority of the veterinary isolates (47/67 = 70.1%) were nested within theFusarium solanispecies complex (FSSC), and these included 8 phylospecies and 33 unique 3-locus sequence types (STs). Three of the FSSC species (Fusarium falciforme,Fusarium keratoplasticum, andFusariumsp. FSSC 12) accounted for four-fifths of the veterinary strains (38/47) and STs (27/33) within this clade. Most of theF. falciformestrains (12/15) were recovered from equine keratitis infections; however, strains ofF. keratoplasticumandFusariumsp. FSSC 12 were mostly (25/27) isolated from marine vertebrates and invertebrates. Our sampling suggests that theFusarium incarnatum-equisetispecies complex (FIESC), with eight mycoses-associated species, may represent the second most important clade of veterinary relevance withinFusarium. Six of the multilocus STs within the FSSC (3+4-eee, 1-b, 12-a, 12-b, 12-f, and 12-h) and one each within the FIESC (1-a) and theFusarium oxysporumspecies complex (ST-33) were widespread geographically, including three STs with transoceanic disjunctions. In conclusion, fusaria associated with veterinary mycoses are phylogenetically diverse and typically can only be identified to the species level using DNA sequence data from portions of one or more informative genes.

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Molecular Characterization of the Fusarium graminearum Species Complex in Japan

Phytopathology ◽

10.1094/phyto-98-2-0159 ◽

2008 ◽

Vol 98 (2) ◽

pp. 159-166 ◽

Cited By ~ 124

Author(s):

H. Suga ◽

G. W. Karugia ◽

T. Ward ◽

L. R. Gale ◽

K. Tomimura ◽

...

Keyword(s):

Fusarium Graminearum ◽

Species Complex ◽

Phylogenetic Analyses ◽

Distinct Species ◽

Sensu Stricto ◽

Rflp Markers ◽

Differential Distribution ◽

The North ◽

Pcr Rflp ◽

Fusarium Graminearum Species Complex

Members of the Fusarium graminearum species complex are important cereal pathogens worldwide and belong to one of at least nine phylogenetically distinct species. We examined 298 strains of the F. graminearum species complex collected from wheat or barley in Japan to determine the species and trichothecene chemotype. Phylogenetic analyses and species-diagnostic polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLPs) revealed the presence and differential distribution of F. graminearum sensu stricto (s. str.) and F. asiaticum in Japan. F. graminearum s. str. is predominant in the north, especially in the Hokkaido area, while F. asiaticum is predominant in southern regions. In the Tohoku area, these species co-occurred. Trichothecene chemotyping of all strains by multiplex PCR revealed significantly different chemotype compositions of these species. All 50 strains of F. graminearum s. str. were of a 15- or 3-acetyl deoxynivalenol type, while 173 (70%) out of 246 strains of F. asiaticum were of a nivalenol type. The possibility of gene flow between the two species was investigated by use of 15 PCR-RFLP markers developed in this study. However, no obvious hybrids were detected from 98 strains examined, including strains collected from regions where both species co-occur.

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Unexpected diversity in the host-generalist oribatid mite Paraleius leontonychus (Oribatida, Scheloribatidae) phoretic on Palearctic bark beetles

PeerJ ◽

10.7717/peerj.9710 ◽

2020 ◽

Vol 8 ◽

pp. e9710

Author(s):

Sylvia Schäffer ◽

Stephan Koblmüller

Keyword(s):

Bark Beetles ◽

Phylogenetic Analyses ◽

Oribatid Mite ◽

Nuclear Gene ◽

Distinct Species ◽

Wide Distribution ◽

Nominal Species ◽

Gene Trees ◽

Complex Interactions ◽

First Case

Bark beetles are feared as pests in forestry but they also support a large number of other taxa that exploit the beetles and their galleries. Among arthropods, mites are the largest taxon associated with bark beetles. Many of these mites are phoretic and often involved in complex interactions with the beetles and other organisms. Within the oribatid mite family Scheloribatidae, only two of the three nominal species of Paraleius have been frequently found in galleries of bark beetles and on the beetles themselves. One of the species, P. leontonychus, has a wide distribution range spanning over three ecozones of the world and is believed to be a host generalist, reported from numerous bark beetle and tree species. In the present study, phylogenetic analyses of one mitochondrial and two nuclear genes identified six well supported, fairly divergent clades within P. leontonychus which we consider to represent distinct species based on molecular species delimitation methods and largely congruent clustering in mitochondrial and nuclear gene trees. These species do not tend to be strictly host specific and might occur syntopically. Moreover, mito-nuclear discordance indicates a case of past hybridization/introgression among distinct Paraleius species, the first case of interspecific hybridization reported in mites other than ticks.

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Source identification of Middle Age extreme event deposits in the Lesser Antilles using forward numerical modeling of tsunami

10.5194/egusphere-egu21-10908 ◽

2021 ◽

Author(s):

Louise Cordrie ◽

Audrey Gailler ◽

Nathalie Feuillet

Keyword(s):

Puerto Rico ◽

Extreme Event ◽

Virgin Islands ◽

Lesser Antilles ◽

Greater Antilles ◽

Seismic Cycle ◽

The Caribbean ◽

Run Up ◽

Bathymetric Grids ◽

Northern Segment

The arc of the Lesser Antilles is one of the most quiet subduction zone in the world. In this region, the convergence of the Atlantic and the Caribbean plates is low (few mm/year) and most of the seismicity is an intraplate and crustal seismicity. Among the Mw>7 earthquakes recorded in the historical catalog (1690 near Barbuda, 1843 near Guadeloupe, 1867 near the Virgin Islands, 1839 offshore Martinica, 1969 offshore Dominica, 1974 near Antigua), only the 1839 and 1843 events are suspected to be interplate earthquakes. The 1867 Virgin Island earthquake generated an important tsunami with waves of 10m that devastated the closest islands. A tsunami followed the 1843 earthquake but without much damage. These two events are the only known damaging tsunami in this region, but another older one might be added to the list. Indeed, an increasing number of tsunami deposits have been identified in the recent years on several islands of the arc, all of them being around 500 years old (~1450 AD). These deposits are all located in the northern segment of the arc, between Antigua and Puerto-Rico, in Anegada, St-Thomas (Virgin Islands), Anguilla and Scrub islands. There is unfortunately no record and no testimonies of an extreme event at that time.The northern segment of the arc is particularly complex because located at the transition between the Greater Antilles and the Lesser Antilles. It is crossed by the Anegada Passage, a series of faults and basins cutting through the arc, which defines the limit between the Puerto-Rico micro-plate and the Caribbean plate. This passage and the numerous intra-arc fault systems present between the islands are active and likely compensate for the plates motion. The very low slip deficit detected with GPS measurements at the subduction contacts of Puerto-Rico and the Lesser Antilles indicates that the interface from Guadeloupe to Puerto-Rico can be considered as totally uncoupled or holding the characteristics of a very long seismic cycle. A tsunami generated by an extreme event 500 years ago in this region could be related to intra-arc, outer-rise, intraplate or interface fault rupture. The identification of the source would enable a better understanding of the seismic cycle and the dynamic of this part of the arc.This study lists and set models of all the potential faults that could trigger an earthquake in the area encompassing the three islands : Anguilla, Anegada and StThomas. We have created high-resolution bathymetric grids and performed tsunami simulations for each fault model. We uses run-up models to compare the simulated wave heights and run-up distance to all the deposits heights and positions. The magnitudes of our fault models range between 7 and 9, but very few of them generate a strong enough tsunami to match the observed deposits.

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The Geology of the British Virgin Islands

Geological Magazine ◽

10.1017/s0016756800086581 ◽

1924 ◽

Vol 61 (8) ◽

pp. 339-351 ◽

Cited By ~ 3

Author(s):

K. W. Earle

Keyword(s):

Dominican Republic ◽

Volcanic Rocks ◽

Virgin Islands ◽

Geological Structure ◽

Lesser Antilles ◽

Greater Antilles ◽

Igneous Intrusion ◽

British Virgin Islands ◽

The Caribbean ◽

Granitoid Intrusions

The geological structure of the British Virgin Islands correlates them indisputably with the Greater and not with the Lesser Antilles. The latter are composed essentially of Tertiary volcanic rocks of andesitic or basaltic type, with or without development of sedimentary strata which, when present, only dip at gentle angles and never show the violent effects of such dynamic forces as have been responsible for the folding and “up-ending” of the strata in the Virgin Islands. The tremendous depth of the channel separating the British Virgin Islands from the Lesser Antilles lias been ascribed to faulting, probably initiated in Pliocene times.The work of Cleve (1), Hill (4), Vaughan (5), and others (6) in the American Virgin Islands, Porto Rico, the Dominican Republic, Cuba, Haiti, and Jamaica, indicates that the British Virgin Islands form geologically only the eastern termination of that main group of islands and have been subjected to the same earth movements as them. The evidence for attributing a Cretaceous age to the sedimentary series has already been referred to.With regard to the age of the folding and igneous intrusion, Vaughan considers that the folding took place between upper Eocene and middle Oligoccne times, and that the intrusion of the diorites took place at approximately the same date. (7)Wythe Cooke considers that the igneous basal complex in the Dominican Republic certainly dates from Cretaceous time, but that part is probably older. He also considers that the stresses that folded and sheared these rocks were probably active during Eocene time or earlier, and that the intrusion of the great masses of dioritic rocks probably occurred before the deposition of the Eocene sediments.According to Hill (4), however, “in mid-Tertiary times granitoid intrusions were pushed upward into the sediments of the Greater Antilles, the Caribbean, Costa Eican, and Panamic regions.” Frazer, on the other hand (8), considered the nuclear axis of Cuba and San Domingo, and possibly of all the Caribbean islands, to be Archaean, a view upheld also by Dr. W. Bergt. (9)There is no doubt that the key to these problems lies in the larger islands of the Greater Antilles, for it is only there that unaltered fossiliferous sediments occur and can be studied in relation to the igneous intrusion and metamorphism. There appears, however, to the writer to be nothing either in the geological or faunal evidence necessarily indicating previous land connexion at any time between the Virgin Islands and the Lesser Antilles, ahd on this matter it is hoped to furnish further evidence at a later date.

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Redescriptions and taxonomic notes on species of the Synalpheus townsendi Coutiere, 1909 complex (Decapoda: Caridea: Alpheidae)

Zootaxa ◽

10.11646/zootaxa.1027.1.1 ◽

2005 ◽

Vol 1027 (1) ◽

pp. 1 ◽

Cited By ~ 3

Author(s):

MARGARITA HERMOSO SALAZAR ◽

MARY WICKSTEN ◽

JUAN J. MORRONE

Keyword(s):

Gulf Of Mexico ◽

Gulf Of California ◽

Species Complex ◽

Distinct Species ◽

Morphological Features ◽

Eastern Pacific ◽

Type Material ◽

The Caribbean

We compared morphological features in 122 specimens of the Synalpheus townsendi species complex from the Caribbean, Gulf of Mexico and eastern Pacific. Our objectives were to examine the taxonomy of S. townsendi townsendi, S. t. mexicanus, S. t. brevispinis and S. t. peruvianus, which we felt have not been appropriately described and to reconsider their status. Based on examination of type material and different characters, we conclude that these taxa should be treated as distinct species, S. townsendi Coutière, 1909; S. mexicanus Coutière, 1909, S. brevispinis Coutière, 1909 and S. peruvianus Rathbun, 1910. We agree with Dardeau, 1986, that S. scaphoceris Coutière, 1910, is a distinct species. Specimens identified as S. townsendi productus Coutière, 1909, overlap in morphology with typical S. townsendi, and therefore are not considered to warrant designation as a separate taxon. Synalpheus mexicanus is not endemic to the Gulf of California.

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Taxonomic status of the Neotropical salamanders Bolitoglossa altamazonica and Bolitoglossa peruviana (Amphibia: Caudata: Plethodontidae), with the description of a new species from Northern Peru

Zootaxa ◽

10.11646/zootaxa.4834.3.3 ◽

2020 ◽

Vol 4834 (3) ◽

pp. 365-406

Author(s):

JUAN C. CUSI ◽

GIUSSEPE GAGLIARDI-URRUTIA ◽

ISABELA CARVALHO BRCKO ◽

DAVID B. WAKE ◽

RUDOLF VON MAY

Keyword(s):

New Species ◽

Species Complex ◽

Phylogenetic Analyses ◽

Nuclear Gene ◽

Taxonomic Status ◽

Genetic Distances ◽

Conservation Area ◽

Northern Peru ◽

Rag 1 ◽

Hands And Feet

We examine the phylogenetic relationships among salamanders of the genus Bolitoglossa (Eladinea) distributed in the Amazonian basin of northern Peru and southern Ecuador and assess species diversity based on morphological and phylogenetic analyses. We infer a molecular phylogeny using sequences from two mitochondrial (Cytb, 16S) and two nuclear genes (RAG–1, POMC). We find two well-supported subclades, one including [B. altamazonica + B. peruviana] + B. awajun sp. n., and the other including Bolitoglossa sp. Ituxi + Bolitoglossa sp. Jurúa. Ecuadorian lineages form divergent clades from the Peruvian lineages. Accordingly, Ecuadorian populations previously assigned to Bolitoglossa peruviana sensu lato are treated as members of a Bolitoglossa equatoriana species complex. A newly defined Bolitoglossa altamazonica species complex contains only populations from the Amazonian rainforest of Peru. Maximum likelihood and Bayesian Inference analyses confirm the phylogenetic placement of B. altamazonica and B. peruviana, and support recognition of a related new species of Bolitoglossa. The uncorrected genetic distances between the new species and B. altamazonica are 6.5% for Cytb and 4.9% for 16S; and the uncorrected genetic distances between the new species and B. peruviana are 8.0% for Cytb and 3.9% for 16S. Additionally, analyses of nuclear gene sequences show no haplotype sharing between the new species and closely related species. The new species is distinguished from its congeners by a combination of the following morphological characters: (1) Standard length mean 37.7 mm in males (range 32.0–42.2; n=5) and 41.4 mm in females (range 34.9–48.2; n=6); (2) in life, dorsal coloration uniformly brown with a dark brown triangular marking between the eyes or some irregular light cream spots or patches on the head, back and flanks; (3) iris pale golden; (4) in preservative, dark brown venter with cream mottlings or moderate-sized blotches on the gular region, belly, cloacal region and tail; (5) tips of third finger and third toe protuberant and pointed with nearly complete webbing on the hands and feet; (6) 11–26 maxillary teeth and 8–24 vomerine teeth. Given that the syntypes of B. altamazonica are lost, we designate a neotype for B. altamazonica from Allpahuayo Mishana National Reserve, Loreto department, Peru. Newly collected specimens from ~30 km NE from Moyobamba (type locality of B. peruviana) provide a better understanding of B. peruviana and enable us to show that it is the sister taxon of B. altamazonica. The new species is known from pre-montane forests in Cordillera Escalera Regional Conservation Area, Cordillera Azul National Park and Shucshuyacu, San Martin department, Peru at 485–1311 m elevation, ~75 km SE from Moyobamba. Bolitoglossa awajun sp. n. is the fourth endemic species of salamander from Peru.

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Molecular, chromosomal and morphological characters reveal a new diploid species in the Smilax china complex (Smilacaceae)

Phytotaxa ◽

10.11646/phytotaxa.212.3.2 ◽

2015 ◽

Vol 212 (3) ◽

pp. 199 ◽

Cited By ~ 1

Author(s):

Yunpeng Zhao ◽

Zhongshuai Sun ◽

Yihan Wang ◽

Chengxin Fu

Keyword(s):

Species Complex ◽

Phylogenetic Analyses ◽

Diploid Species ◽

Distinct Species ◽

Morphological Characters ◽

Molecular Data ◽

Eastern Asia ◽

Diploid Population ◽

Species Complexes ◽

Molecular Phylogenetic

The Smilax china complex (Smilacaceae) is a typical mixoploid species complex including five extant diploid taxa with a widespread distribution across eastern Asia. The diploid population (mHB, 2n = 32), which was originally considered to be diploid S. china, together with two newly discovered diploid populations (mZZ and mYXS) is supported here as a distinct species by morphological, karyotypic and molecular data. These three populations present consistent morphological characters of sub-erect stems, rudimentary tendrils and minutely serrulate leaf margins, in which they differ from S. china. Molecular phylogenetic analyses also confirm its monophyly with a closer relationship to the other two erect species S. biflora and S. trinervula in the complex. These three populations are thus proposed to be a clear new diploid species and described with the name of Smilax microdontus Z. S. Sun & C.X. Fu, sp. nov. The discovery of this new species highlights the importance of closer examinations on species complexes by integrating multiple evidence.

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Disentangling the taxonomic status and phylogeographic structure of Marmora’s (Curruca sarda) and Balearic Warbler (Curruca balearica): a genetic multi-marker approach

Journal of Ornithology ◽

10.1007/s10336-021-01885-x ◽

2021 ◽

Author(s):

Davide Nespoli ◽

Irene Pellegrino ◽

Marco Galaverni ◽

Romolo Caniglia ◽

Joseph Sunyer ◽

...

Keyword(s):

Sibling Species ◽

Species Complex ◽

Genetic Variance ◽

Nuclear Gene ◽

Taxonomic Status ◽

Distinct Species ◽

Integrative Taxonomy ◽

Genetic Distances ◽

Phylogeographic Structure ◽

Different Populations

AbstractMarmora’s Warbler (Curruca sarda) and Balearic Warbler (C. balearica) are allopatric sibling species and were recently split mostly based on morphological and ethological characteristics. Here we provide the first phylogenetic and phylogeographic analyses of this species complex to support the taxonomic status of C. sarda and C. balearica in light of integrative taxonomy. We sampled the two taxa in most of their breeding ranges and we sequenced three mitochondrial and one nuclear gene region. All C. balearica individuals had private haplotypes for the four markers and formed monophyletic clades. Genetic distances between the two taxa were comparable with those found between other species belonging to the Curruca genus. Furthermore, most of the genetic variance was expressed at the interspecific level, rather than between different populations within taxa or between individuals within populations. Our results strongly support the current taxonomic status of these two warblers as distinct species.

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