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A molecular and morphological characterization of Oliver's parrot snake, Leptophis coeruleodorsus (Squamata: Serpentes: Colubridae) with the description of a new species from Tobago
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Currently, two snake species of the genus Leptophis occur in Trinidad and Tobago. One, L. stimsoni, is endemic to Trini-dad's Northern Range and known from relatively few specimens. The second is the diurnal, arboreal, brightly colored par-rot snake Leptophis coeruleodorsus Oliver. It was originally described based on 23 specimens from Trinidad, Tobago, and four locations in northern Venezuela but remains poorly known. It was later assigned as a subspecies of Leptophis ahaet-ulla; a widespread, polytypic species. Here we compare 11 specimens of the L. ahaetulla Group using DNA sequences from two mitochondrial genes (cytochrome b and 16S, 1,383 bp total) from island and mainland populations, report on the variation in the morphology of 54 museum specimens of Leptophis a. coeruleodorsus; describe the previously unde-scribed holotype of L. coeruleodorsus Oliver, and restrict its type locality. Additionally, we describe a new species of Lep-tophis from the island of Tobago that can be distinguished from L. coeruleodorsus on the basis of snout shape, upper labial architecture, elongated prefrontal scales, and ventral scale counts. The new Leptophis raises the number of endemic To-bago amphibians and reptiles to 11 taxa.
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... Traditionally ranked as a genus, Leptophis is nested within Colubrinae (Zaher et al., 2019) and currently contains 12 recognized species. Of these, L. ahaetulla sensu lato is the most widespread species of Leptophis, with 10 subspecies occurring from Mexico to Argentina (Albuquerque, 2009;Murphy et al., 2013). Based on a comprehensive taxonomic revision using morphological and coloration characters, Albuquerque (2008) proposed in his unpublished dissertation recognition of subspecies of L. ahaetulla sensu lato as distinct species. ...
... Taxonomic studies describing new species of Leptophis have presented molecular phylogenies with improved sampling. Murphy et al. (2013) analyzed 11 samples of five subspecies of L. ahaetulla, although other congenerics were excluded. Albuquerque et al. (in press) presented the most complete phylogeny to date, which is based on the mitochondrial 16S gene and 17 samples of five species. ...
... Of these, the Central American species L. mexicanus and L. modestus might be closely related to L. depressirostris and L. diplotropis as these are the only four species of Leptophis that have a loreal scale (Henderson, 1976;Hoyt, 1964). Likewise, morphological similarity suggests that L. haileyi, recently described from a single specimen from Tobago, is closely related to sympatric L. coeruleodorsus (Murphy et al., 2013). Among subspecies of L. ahaetulla sensu lato recognized as species by Albuquerque (2008), we did not include L. bolivianus (Bolivia), L. liocercus (eastern Brazil), L. praestans (Central America) and L. urostictus (W Colombia). ...
Tetrapod taxa with broad geographic distributions across the Neotropics are often composed of multiple evolutionary lineages. In this paper, we present the most complete phylogeny of Leptophis to date and assess morphology-based species limits within the broadly distributed green parrot snake Leptophis ahaetulla sensu lato, which occurs from Mexico to Argentina. Although L. ahaetulla sensu stricto, L. nigromarginatus and L. occidentalis were recovered as paraphyletic, tree topology tests failed to reject their monophyly. Monophyly of L. bocourti, L. coeruleodorsus, L. cupreus, L. depressirostris, L. dibernardoi, L. marginatus, and L. riveti was strongly supported. Our phylogenetic trees support recognition of multiple species within Leptophis ahaetulla sensu lato and suggest that color evolution and the uptlift of the Andes played an important role in the diversification of parrot snakes.
... Both dates are consistent with the proposed land bridge connections during the Pleistocene (Murphy 1997). Trinidad and Tobago's near endemic Oliver's Parrot Snake Leptophis coeruleodorsus shows very low genetic divergence between islands (0.26%), which is further evidence of a recent connection between the two main islands or a recent over-water colonization event of Tobago from Trinidad (Murphy et al. 2013). ...
The Trinidad and Tobago archipelago is in the southern Caribbean between the Caribbean Sea and the central Atlantic Ocean, northeast of Venezuela. The sister islands are often cited as the southernmost islands of the Lesser Antilles. However, Trinidad is a continental island with strong geologic and geomorphic
connections to mainland South America, having separated approximately 4 Ma. Tobago, on the other hand, is a far-traveled, Cretaceous oceanic arc that formed at the leading edge of the Caribbean plate and was accreted onto the northern coast of South America. Consequently, neither of the two islands are part of the Neogene Lesser Antilles Island arc.
... Both dates are consistent with the proposed land bridge connections during the Pleistocene (Murphy 1997). Trinidad and Tobago's near endemic Oliver's Parrot Snake Leptophis coeruleodorsus shows very low genetic divergence between islands (0.26%), which is further evidence of a recent connection between the two main islands or a recent over-water colonization event of Tobago from Trinidad (Murphy et al. 2013). ...
The Trinidad-Tobago archipelago contains two major islands and about 25 satellite islands ranging in size from 3.6 km² to less than 1 ha. Despite different origins, both islands with satellites share a continental biota and have a rich snake fauna originating from vicariance and dispersal events. The authors used published molecular and morphological data to compare the two faunas and here discuss their origins and biogeography. Relatively high snake diversity and local endemics are present on both islands, which share some species with each other or with the mainland. Spatiotemporal distribution patterns illuminated by genetic clocks enhance understanding of evolution in the region and provide a more general example for the study of other biogeographic patterns. The authors also examined the literature for historical records. Trinidad shares many species with the Paria Peninsula in Eastern Venezuela, while Tobago species are more closely related to those from Venezuela’s more distant Central Caribbean Coastal Range.
... The checklist for Tobago is continually expanding as numerous cryptic species are documented, as reviewed by Murphy and Downie (2012), most notably lizards, snakes and frogs (for example new Leptophis sp. (Murphy et al. 2013)). Despite this, terrestrial and freshwater turtles are seemingly understudied possibly owing to their rarity on the island. ...
Within the last decade, there has been growing attention toward the herpetofauna of Tobago. The checklist for Tobago is continually expanding as numerous cryptic species are documented. Here, we review the Emydidae (pond and river turtles) and the accounts of Testudinidae families (Tortoises).
... The Green Parrot Snake, Leptophis ahaetulla, is one of 11 species currently included in the colubrid genus Leptophis (Murphy et al., 2013). In Mexico, this species is found in the states of Veracruz, Tabasco, Campeche, Quintana Roo, Oaxaca, and Chiapas, and its distribution extends southward through Central America to Ecuador, Brazil, and Argentina (Lee, 1996;Campbell, 1998;Köhler, 2008;Johnson et al., 2010;Wallach et al., 2014), at elevations from sea199 level to 1,300 m (Köhler, 2008). ...
The Neotropical parrot snake genus Leptophis comprises a group of 12 colubrine snakes widely distributed in Mexico, Central- and South America. Among the currently recognized taxa in the genus, L. ahaetulla constitutes a morphologically diverse assemblage of typically slender snakes, with subspecies recorded from Mexico to most of South America. Though extremely variable in scalation, coloration, size and dentition, many of these subspecies are still poorly known, with at least three being known from few specimens, hampering the diagnosability and determination of the taxonomic status of certain populations. Accumulation of new specimens and new analytical approach for species delimitation supported a comprehensive taxonomic revision of these snakes based on the examination of meristic, morphometric, color pattern and hemipenial characters of 1625 specimens. Accordingly, the following taxa are herein referred to as full species: L. a. ahaetulla, L. a. bocourti, L. a. bolivianus, L. a. liocercus, L. a. marginatus, L. a. nigromarginatus, L. a. occidentalis, L. a. praestans and L. a. urostictus. Moreover, L. a. ortoni is placed in the synonymy of L. nigromarginatus, whereas L. coeruleodorsus, a former subspecies recently elevated to species rank, is redescribed, and L. haileyi is placed in the synonymy of this latter taxon. In addition, a dichotomous key including all recognized species of Leptophis is provided.
We describe a new species of Leptophis from the Caatinga ecoregion encompassing the semi-arid region of Brazil. Phylogenetic analysis of 16S rDNA sequences indicate that the new species is nested deep within the L. ahaetulla complex. The new species differs from all other congeners in the following unique character combination: two dorsolateral Light Emerald Green (142) to Robin's Egg Blue (161) stripes separated from each other by Pale Buff (1) to Smoke Gray (266) vertebral stripe (continuous to tail) present; loreal scale absent; maxillary teeth 2124; ventrals 158177; subcaudals 137162; black spots on head absent; supracephalic plates of head not edged with black pigment; adult color pattern lacking dark oblique bands; keels absent on first dorsal scale rows; hemipenis unilobed, capitate, with undivided sulcus spermaticus. The new species is distinguished from L. ahaetulla ahaetulla by the Light Emerald Green (142) to Robin's Egg Blue (161) (in life) dorsolateral stripes separated from each other by a Pale Buff (1) to Smoke Gray (266) vertebral stripe (at least anteriorly), and by having white to Pale Sulphur Yellow (92) scales on the first (on anterior region of body) to fourth (midbody region) scale rows [vs. Light Grass Green (109) to Light Emerald Green (142) with Yellow Ocher (14), Cinnamon-Drab (50) or Sulphur Yellow (80) vertebral stripe; second to thirdoccasionally the fourthscale rows Sulphur Yellow (80), at least anteriorly], wider snout (vs. narrow), postocular stripe wider (vs. narrow), basal region of hemipenis with 1014 spines and first row of hemipenial body with 89 spines (vs. 1822 in the basal region and 58 in the first row). The new species differs from L. a. liocercus, which is also distributed in the Northeast Region Brazil with a small overlap in distribution, by the dorsolateral stripes (vs. dorsum unstriped), and 1822 spines in the fourth row of the hemipenial body (vs. 1118). Recognition of the new species is also consistent with uncorrected pairwise distances between 16S rDNA sequences.
The material collected by Roberto Donoso Barros in Venezuela between 1963 and 1964 deposited at the Universidad de Concepción in Chile is catalogued and commented. Species are ordered following current systematic; specimens and species of interest are commented, especially those type material described by RDB.
Subspecies have been considered artificial subdivisions of species, pattern classes, or incipient species. However, with more data and modern phylogenetic techniques, some subspecies may be found to represent true species. Mitochondrial DNA analysis of the polytypic snake, Elaphe obsoleta, yields well-supported clades that do not conform to any of the currently accepted subspecies. Complete nucleotide sequences of the cytochrome b gene and the mitochondrial control region produced robust maximum-parsimony and maximum-likelihood trees that do not differ statistically. Both trees were significantly shorter than a most parsimonious tree in which each subspecies was constrained to be monophyletic. Thus, the subspecies of E. obsoleta do not represent distinct genetic lineages. Instead, the evidence points to three well-supported mitochondrial DNA clades confined to particular geographic areas in the eastern United States. This research underscores the potential problems of recognizing subspecies based...
The application of genetic approaches has enhanced the identification of cryptic species in a wide variety of taxa, often with immediate conservation implications. Here, we employed multilocus DNA analyses to assess genetic variation and its correspondence to taxonomy within the Mealy Amazon (Amazona farinosa), a parrot species found in Central and South America. DNA sequence data from four mitochondrial regions and two nuclear introns were used to infer relationships among all five named subspecies in this species complex. Two reciprocally monophyletic groups with strong nodal support were found; one comprised of the two Central American subspecies guatemalae and virenticeps and one including all three South American subspecies farinosa,
chapmani, and inornata. Molecular characters diagnosed distinct Central American and South American lineages, with an estimated divergence time of 1.75–2.70 million years ago as inferred from cytochrome-b (3.5–5.4 % corrected distance). Our data support recognizing Central American and South American Mealy Amazons as separate species worthy of independent conservation management. Furthermore, our results suggest recognition of two separate management units within the South American clade, although further study is required. These findings have important conservation implications as Central American A. farinosa are under increased pressure from habitat destruction and collection for the pet trade, yet are listed as of Least Concern due to their current classification as subspecies’ subsumed within the species complex.
Abstract: Leptophis cupreus is redescribed on the basis of 18 specimens, including the holotype. The species is characterized by having a uniformly copper-colored dorsum, which distinguishes it from all other known species of Leptophis. We present photographs of the holotype and a living specimen of L. cupreus, describe and illustrate the everted hemipenis, and plot its known distribution.
A tentative checklist of 16 amphibian and 42 reptilian species from the central Venezuelan Llanos is presented along with notes on the ecology of many of the species from this herpetologically poorly known area. Fifty state records from the states of Apure and Guarico are included.
— We studied sequence variation in 16S rDNA in 204 individuals from 37 populations of the land snail Candidula unifasciata (Poiret 1801) across the core species range in France, Switzerland, and Germany. Phylogeographic, nested clade, and coalescence analyses were used to elucidate the species evolutionary history. The study revealed the presence of two major evolutionary lineages that evolved in separate refuges in southeast France as result of previous fragmentation during the Pleistocene. Applying a recent extension of the nested clade analysis (Templeton 2001), we inferred that range expansions along river valleys in independent corridors to the north led eventually to a secondary contact zone of the major clades around the Geneva Basin. There is evidence supporting the idea that the formation of the secondary contact zone and the colonization of Germany might be postglacial events. The phylogeographic history inferred for C. unifasciata differs from general biogeographic patterns of postglacial colonization previously identified for other taxa, and it might represent a common model for species with restricted dispersal.