Systematic relationships of the Guianan brush-tailed rat (Isothrix sinnamariensis ) and its first occurrence in Guyana / Systématique du rat à queue en brosse de Guyane ( Isothrix sinnamariensis ) et première découverte en Guyane

Mammalia ◽  
2006 ◽  
Vol 70 (1-2) ◽  
Author(s):  
Burton K. Lim ◽  
Mark D. Engstrom ◽  
John C. Patton ◽  
John W. Bickham
Keyword(s):  
Dna Sequences ◽  
French Guiana ◽  
Tropical Rainforest ◽  
Sequence Difference ◽  
Separate Species ◽  
Adult Females ◽  
First Occurrence ◽  
Systematic Relationships ◽  
Average Sequence ◽  
Morphological Differences

AbstractIsothrix sinnamariensis was originally described and known only from French Guiana. We document the first occurence of this species from Guyana. A single sub-adult male was collected in lowland tropical rainforest near the headwaters of the Essequibo River. Although smaller in external and cranial size than the two adult females of the type description, our third known specimen represents the basal lineage to the type-series clade, with an average sequence difference of 1.72% based on cytochrome b mitochondrial DNA sequences. However, the degree of morphological and genetic divergence (2.67%) between I. sinnamariensis and its sister taxon I. pagurus is substantially less than the chromosomal differences originally used to distinguish them as two separate species. In contrast, distinctive karyotypes, morphological differences, and higher levels of mtDNA divergence (13.48%) between the other two species recognized, I. negrensis that was recently separated from I. bistriata , suggest an earlier and deeper diversification for these taxa.

Systematic relationships of the Guianan brush-tailed rat (Isothrix sinnamariensis ) and its first occurrence in Guyana / Systématique du rat à queue en brosse de Guyane ( Isothrix sinnamariensis ) et première découverte en Guyane

Mammalia ◽  
2006 ◽  
Vol 70 (1-2) ◽  
Author(s):  
Burton K. Lim ◽  
Mark D. Engstrom ◽  
John C. Patton ◽  
John W. Bickham
Keyword(s):  
Dna Sequences ◽  
French Guiana ◽  
Tropical Rainforest ◽  
Sequence Difference ◽  
Separate Species ◽  
Adult Females ◽  
First Occurrence ◽  
Systematic Relationships ◽  
Average Sequence ◽  
Morphological Differences

AbstractIsothrix sinnamariensis was originally described and known only from French Guiana. We document the first occurence of this species from Guyana. A single sub-adult male was collected in lowland tropical rainforest near the headwaters of the Essequibo River. Although smaller in external and cranial size than the two adult females of the type description, our third known specimen represents the basal lineage to the type-series clade, with an average sequence difference of 1.72% based on cytochrome b mitochondrial DNA sequences. However, the degree of morphological and genetic divergence (2.67%) between I. sinnamariensis and its sister taxon I. pagurus is substantially less than the chromosomal differences originally used to distinguish them as two separate species. In contrast, distinctive karyotypes, morphological differences, and higher levels of mtDNA divergence (13.48%) between the other two species recognized, I. negrensis that was recently separated from I. bistriata , suggest an earlier and deeper diversification for these taxa.

scholarly journals The identification of the species of the ‘Spilogona contractifrons species-group’ and the ‘Spilogona nitidicauda species-group’ (Diptera, Muscidae) based on morphological and molecular analysis

2018 ◽  
Author(s):  
Vera S. Sorokina ◽  
Elena V. Shaikevich
Keyword(s):  
Dna Sequences ◽  
Morphological Characters ◽  
Species Group ◽  
Genetic Distances ◽  
Valid Species ◽  
Separate Species ◽  
Cytochrome Oxidase I Gene ◽  
Male Head ◽  
Morphological Differences ◽  
I Gene

Muscid species of the ‘Spilogona contractifrons species-group’ (Spilogona alticola (Malloch, 1920), S. arctica (Zetterstedt, 1838), S. contractifrons (Zetterstedt, 1838), S. orthosurstyla Xue & Tian, 1988) and of the ‘Spilogona nitidicauda species-group’ (S. nitidicauda (Schnabl, 1911), S. hissarensis Hennig, 1959, S. imitatrix (Malloch, 1921), S. platyfrons Sorokina, 2018) are notoriously difficult to distinguish. In this paper, their morphological features are analysed, images of the male head, frons and abdomen of all the species are given, and the male terminalia are figured. The study of extensive material has shown that all the morphologically recognised species in each of these groups are valid species. An identification key is provided for both groups of species. To confirm the morphological differences, genetic differences in the cytochrome oxidase I gene of flies of the ‘Spilogona contractifrons species-group’ and of the ‘Spilogona nitidicauda species-group’ were analysed. It is shown that members of both groups of species have not only distinguishing morphological characters but also fixed substitutions in the DNA sequences. Since a low interspecific polymorphism is known in the Muscidae Latreille, 1802, the revealed genetic distances confirm the existence of separate species or subspecies in each of the groups studied.

Polymorphism and pore signature patterns in the copepod genus Oncaea (Cyclopoida)

1983 ◽  
Vol 63 (2) ◽  
pp. 449-466 ◽  
Author(s):  
S. J. Malt
Keyword(s):  
Cyclopoid Copepod ◽  
Similar Species ◽  
Short Hair ◽  
Separate Species ◽  
Adult Females ◽  
Adult Pattern ◽  
Hair Sensilla ◽  
Signature Pattern ◽  
Polymorphic Forms ◽  
Morphological Differences

Species of the cyclopoid copepod genus Oncaea are commonly polymorphic. Using material from several localities, forms of O. venusta Philippi, O. mediterranea Claus and O. conifer a Giesbrecht are described, and specimens of two closely related and morphologically similar species, O. ornata Giesbrecht and O. englishi Heron, are compared. The integumental pore signature patterns of all these species are mapped from stained, tissue-free integuments. Each species has its own characteristic pore signature pattern and sexual dimorphism is confined to the urosomal pore pattern. Similarly the prosomal pore patterns of female copepodid 5 do not usually differ from those of adult females, but urosomal patterns are distinct. Juveniles of O. conifera are exceptional in this respect; their prosomal pore pattern lacks the detail of the adult pattern. Differences in the pore signatures of O. ornata and O. englishi confirm their status as separate species. Signatures in the O. conifera ‘group’ may also prove to be distinct. Whereas intraspecific variation in pore signatures may exist at a level below the resolution of this technique, such small morphological differences should be considered to be taxonomically insignificant.The implications of polymorphism in the process of speciation, and the mechanisms by which the polymorphic forms are maintained are discussed.Scanning electron microscopy and light microscopy are used to examine the morphology of pores and their associated sensilla. Three types of sensilla are described, peg, short-hair and long-hair sensilla.

Molecular phylogenetic position of Haplometroides intercaecalis (Digenea, Plagiorchiidae)

2018 ◽  
Vol 63 (3) ◽  
pp. 522-526 ◽  
Author(s):  
Maria Isabel Müller ◽  
Drausio Honorio Morais ◽  
Reinaldo José da Silva
Keyword(s):  
Dna Sequences ◽  
Additional Data ◽  
Ribosomal Gene ◽  
Valid Species ◽  
Phylogenetic Position ◽  
Systematic Analysis ◽  
Future Studies ◽  
New Family ◽  
Molecular Phylogenetic ◽  
Morphological Differences

Abstract Three valid species of Haplometroides Odhner, 1910 parasitise snakes and amphisbaenians from South America. This study provides additional data on morphometric and molecular phylogenetic position inferred from the nuclear ribosomal gene 28S (partial). DNA sequences were isolated from Haplometroides intercaecalis Silva, Ferreira and Strüssmann, 2007 found in one specimen of Phalotris matogrossensis Lema, D’Agostini and Cappellari, 2005. Five digenean specimens were recovered from the esophagus of this snake, and four specimens were used for morphometrical studies and one specimen for molecular analysis. Phylogenetic analysis using maximum likelihood and Bayesian methods was conducted with sequences available for the order Plagiorchiida and its phylogenetic position places H. intercaecalis among the brachycoeliids Brachycoelium (Dujardin, 1845) Stiles and Hassall, 1898 and Parabrachycoelium Pérez-Ponce de León, Mendoza-Garfias, Razo-Mendivil and Parra-Olea, 2011, and the mesocoeliid Mesocoelium Odhner, 1910, not closely related to plagiorchids as expected. Due to morphological differences among these families, it may be necessary to create a new family to accommodate Haplometroides spp. However, more genera/taxa as well as other molecular markers should be added in future studies to confirm our results and resolve this matter. This is the first phylogenetic positioning of digeneans of the genus Haplometroides, contributing to the systematic analysis of the helminthological biodiversity of Neotropical snakes.

scholarly journals Three new species of leaflitter frogs from the upper Amazon forests: cryptic diversity within Pristimantis "ockendeni" (Anura: Strabomantidae) in Ecuador

Zootaxa ◽  
2008 ◽  
Vol 1784 (1) ◽  
pp. 11 ◽  
Author(s):  
KATHRYN R. ELMER ◽  
DAVID C. CANNATELLA
Keyword(s):  
New Species ◽  
Dna Sequences ◽  
Amazon Basin ◽  
Single Species ◽  
Cryptic Diversity ◽  
Morphological Differences ◽  
Three New Species ◽  
Multiple Species

We describe three new species of Pristimantis leaflitter frogs from the upper Amazon basin of Ecuador: Pristimantis achuar, Pristimantis altamnis, and Pristimantis kichwarum. Each of these new species was previously considered to be part of a single species, formerly known as Eleutherodactylus ockendeni (Boulenger) morph B. However, analysis of DNA sequences together with examination of the morphology of more than 600 specimens from Ecuador reveals that multiple species were confused under the same name. The morphological differences among the three new species are subtle but consistent: presence or absence of a black canthal stripe and/or supratympanic ridge, snout-vent length, and ventral colouration. The three species are generally allopatric and geographically restricted, although at some localities two of the species occur sympatrically.Describimos tres especies nuevas de ranas del sotobosque de la cuenca Amazónica Ecuatoriana: Pristimantis achuar, Pristimantis altamnis y Pristimantis kichwarum. Estas especies fueron consideradas antes como una sola especie bajo el nombre Eleutherodactylus ockendeni (Boulenger) morfo B. Sin embargo, el análisis de secuencias de ADN y la examinación de la morfología de más que 600 especímenes Ecuatorianos indican que en realidad existen tres especies. Sus diferencias morfológicas son sutiles pero constantes: presencia o ausencia de una raya cantal negra y/o de un pliegue supratimpánico y su coloración ventral. Las tres especies tienen distribuciones alopátricas y distintas aunque en algunas localidades se puede encontrar dos de las tres especies juntas.

scholarly journals Rapid root assimilation of added phosphorus in a lowland tropical rainforest of French Guiana

2020 ◽  
Vol 140 ◽  
pp. 107646 ◽  
Author(s):  
Leandro Van Langenhove ◽  
Ivan A. Janssens ◽  
Lore Verryckt ◽  
Laetitia Brechet ◽  
Iain P. Hartley ◽  
...  
Keyword(s):  
French Guiana ◽  
Tropical Rainforest

Mitochondrial DNA sequence evidence supporting the recognition of a new North Atlantic Pseudostichopus species (Echinodermata: Holothuroidea)

2004 ◽  
Vol 84 (5) ◽  
pp. 1077-1084 ◽  
Author(s):  
Francisco A. Solís-Marín ◽  
David S.M. Billett ◽  
Joanne Preston ◽  
Alex D. Rogers
Keyword(s):  
Dna Sequences ◽  
Mitochondrial Gene ◽  
Distinct Species ◽  
Molecular Study ◽  
Morphological Characters ◽  
Coi Gene ◽  
Species Status ◽  
Separate Species ◽  
The Family ◽  
A New Species

A new species of the synallactid sea cucumber genus Pseudostichopus is described, P. aemulatus sp. nov., based on genetic (DNA sequences of the mitochondrial gene Cytochrome Oxidase I [COI] gene) and morphological characters. A comparative molecular study with two other species of the same genus (P. villosus and P. mollis) and from a different family (Isostichopus fuscus) was carried out in order to clarify its taxonomic identity. The nucleotide distance between P. aemulatus sp. nov. and P. villosus and P. mollis is sufficient to support distinct species status. The estimated difference in the number of amino acids, coded for by a partially sequenced COI gene, within the species of the family Synallactidae ranged from 4 to 18. The phylogenetic analysis clearly supports separate species status of these sympatric morphotypes, as indicated by the morphological analysis.

Overlooked morphological variation and a proposal for a new taxonomic circumscription of Alyssum simplex (Brassicaceae)

Phytotaxa ◽  
2019 ◽  
Vol 416 (2) ◽  
pp. 149-166
Author(s):  
VERONIKA CETLOVÁ ◽  
JAVIER FUERTES-AGUILAR ◽  
DARIA IUDOVA ◽  
STANISLAV ŠPANIEL
Keyword(s):  
Genome Size ◽  
Genetic Markers ◽  
Geographic Distribution ◽  
Morphological Variation ◽  
Related Species ◽  
Evolutionary History ◽  
Separate Species ◽  
Taxonomic Treatment ◽  
Morphological Differences

A recent study of European annual taxa of Alyssum has revealed that A. simplex includes two cytotypes (diploid and tetraploid) which differ in genetic markers, evolutionary history, and monoploid relative genome size. In this paper we present a new taxonomic treatment of A. simplex in which we treat the two cytotypes as two separate species. We select and discuss suitable names for both taxa (diploid A. simplex and tetraploid A. collinum), examine their morphological differences and survey their geographic distribution. In addition, we compare both cytotypes with the morphologically similar and genetically related species A. strigosum and designate lectotypes and a neotype of several relevant names.

A new species of Leptolalax (Anura: Megophryidae) from northern Vietnam

Zootaxa ◽  
2017 ◽  
Vol 4243 (3) ◽  
pp. 544 ◽  
Author(s):  
JODI J. L. ROWLEY ◽  
VINH Q. DAU ◽  
HUY D. HOANG ◽  
DUONG T. T. LE ◽  
TIMOTHY P. CUTAJAR ◽  
...  
Keyword(s):  
New Species ◽  
16S Rrna ◽  
Dna Sequences ◽  
Dominant Frequency ◽  
Rrna Gene ◽  
Adult Males ◽  
Skin Texture ◽  
Adult Females ◽  
A New Species ◽  
The 16S Rrna Gene

We describe a new, medium-sized Leptolalax species from Vietnam. Leptolalax petrops sp. nov. is distinguished from its congeners by a combination of having a medium-sized body (23.6–27.6 mm in 21 adult males, 30.3–47.0 mm in 17 adult females), immaculate white chest and belly, no distinct black markings on the head, highly tuberculate skin texture, toes lacking webbing and with narrow lateral fringes, and a call consisting of an average of four notes and a dominant frequency of 5.6–6.4 kHz (at 24.5–25.3 °C). Uncorrected sequence divergences between L. petrops sp. nov. and all homologous DNA sequences available for the 16S rRNA gene are >8%. 

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