Morphological and molecular characterisation of Panagrellus spp. (Cephalobina: Panagrolaimidae): taxonomic status and phylogenetic relationships

Nematology ◽  
2006 ◽  
Vol 8 (6) ◽  
pp. 921-938 ◽  
Author(s):  
S. Patricia Stock ◽  
Steven Nadler
Keyword(s):  
Sequence Data ◽  
Principal Component ◽  
Taxonomic Status ◽  
Single Species ◽  
Morphological Characters ◽  
Morphological Data ◽  
Lsu Rdna ◽  
Type Specimens ◽  
Worldwide Distribution ◽  
Tree Topologies

AbstractThe genus Panagrellus currently comprises 12 known species. These nematodes have a worldwide distribution and have been found in a variety of habitats such as slime flux, thermal springs, insect frass and spoiled cider. Diagnosis of Panagrellus species is rather problematic since few morphological features can be used to discriminate between species and the original publications do not indicate the number of specimens measured and lack standard descriptions of variance. In this study we review the taxonomic status of several species from this genus combining classical morphological data and molecular sequences. Eleven live isolates and fixed material from currently available type specimens representing six Panagrellus species were included. Morphological analysis included the examination of qualitative and quantitative characters of males and females. The taxonomic utility of morphometric data was evaluated by means of multivariate statistics (principal component and canonical discriminant analyses). Phylogenetic inference was based on analysis of nucleotide sequences from the LSU rDNA gene and morphological characters. Parsimony tree topologies inferred from nucleotide datasets strongly supported monophyly of the P. dubius isolates, but not the P. redivivus isolates. Phylogenetic interpretation of these rDNA sequence data suggests that both the P. redivivus and P. dubius isolates each include more than a single species. Only two of the 15 morphological characters evaluated were variable within the ingroup taxa. A long spicule bifurcation length maps on the combined evidence trees as a putative synapmorphy for P. dubius, whereas male D% was homoplastic within isolates of that species. The diagnosis of the genus Panagrellus is emended.

scholarly journals Toward a Natural Classification of Botryosphaeriaceae: A Study of the Type Specimens of Botryosphaeria sensu lato

2021 ◽  
Vol 12 ◽  
Author(s):  
Ying Zhang ◽  
Yupei Zhou ◽  
Wei Sun ◽  
Lili Zhao ◽  
D. Pavlic-Zupanc ◽  
...  
Keyword(s):  
Dna Sequence ◽  
Dna Sequences ◽  
Sequence Data ◽  
Morphological Characteristics ◽  
Taxonomic Status ◽  
Morphological Characters ◽  
Phylogenetic Position ◽  
Type Specimens ◽  
Natural Classification ◽  
Dna Sequence Data

The genus Botryosphaeria includes more than 200 epithets, but only the type species, Botryosphaeria dothidea and a dozen or more other species have been identified based on DNA sequence data. The taxonomic status of the other species remains unconfirmed because they lack either morphological information or DNA sequence data. In this study, types or authentic specimens of 16 “Botryosphaeria” species are reassessed to clarify their identity and phylogenetic position. nuDNA sequences of four regions, ITS, LSU, tef1-α and tub2, are analyzed and considered in combination with morphological characteristics. Based on the multigene phylogeny and morphological characters, Botryosphaeria cruenta and Botryosphaeria hamamelidis are transferred to Neofusicoccum. The generic status of Botryosphaeria aterrima and Botryosphaeria mirabile is confirmed in Botryosphaeria. Botryosphaeria berengeriana var. weigeliae and B. berengeriana var. acerina are treated synonyms of B. dothidea. Botryosphaeria mucosa is transferred to Neodeightonia as Neodeightonia mucosa, and Botryosphaeria ferruginea to Nothophoma as Nothophoma ferruginea. Botryosphaeria foliicola is reduced to synonymy with Phyllachorella micheliae. Botryosphaeria abuensis, Botryosphaeria aesculi, Botryosphaeria dasylirii, and Botryosphaeria wisteriae are tentatively kept in Botryosphaeria sensu stricto until further phylogenetic analysis is carried out on verified specimens. The ordinal status of Botryosphaeria apocyni, Botryosphaeria gaubae, and Botryosphaeria smilacinina cannot be determined, and tentatively accommodate these species in Dothideomycetes incertae sedis. The study demonstrates the significance of a polyphasic approach in characterizing type specimens, including the importance of using of DNA sequence data.

scholarly journals Geopolitical species revisited: genomic and morphological data indicate that the roundtail chubGila robustaspecies complex (Teleostei, Cyprinidae) is a single species

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5605 ◽  
Author(s):  
Joshua M. Copus ◽  
W. L. Montgomery ◽  
Zac H. Forsman ◽  
Brian W. Bowen ◽  
Robert J. Toonen
Keyword(s):  
Single Species ◽  
Molecular Data ◽  
Morphological Data ◽  
Nominal Species ◽  
Type Specimens ◽  
Climate Conditions ◽  
Management Plans ◽  
Tree Topologies ◽  
Wet And Dry Cycles ◽  
Tree Building

TheGila robustaspecies complex in the Lower Colorado River Basin has a complicated taxonomic history. Recent authors have separated this group into three nominal taxa,G. robusta,G. intermedia, andG. nigra, however aside from location, no reliable method of distinguishing individuals of these species currently exists. To assess relationships within this group, we examined morphology of type specimens and fresh material, and used RADseq methods to assess phylogenetic relationship among these nominal species. Maximum likelihood and Bayesian inference tree building methods reveal high concordance between tree topologies based on the mitochondrial and nuclear datasets. Coalescent SNAPP analysis resolved a similar tree topology. Neither morphological nor molecular data reveal diagnostic differences between these species as currently defined. As such,G. intermediaandG. nigrashould be considered synonyms of the seniorG. robusta. We hypothesize that climate driven wet and dry cycles have led to periodic isolation of population subunits and subsequent local divergence followed by reestablished connectivity and mixing. Management plans should therefore focus on retaining genetic variability and viability of geographic populations to preserve adaptability to changing climate conditions.

Le statut des Euphrasia borealis, E. nemorosa et E. stricta dans l'est de l'Amérique du Nord : une analyse numérique

1988 ◽  
Vol 66 (11) ◽  
pp. 2208-2216
Author(s):  
Stephen R. Downie ◽  
Andrée Quintin ◽  
John McNeill
Keyword(s):  
North America ◽  
Principal Component ◽  
Taxonomic Status ◽  
Single Species ◽  
Morphological Characters ◽  
Data Matrix ◽  
Cauline Leaf ◽  
Operational Taxonomic Units ◽  
Considerable Controversy ◽  
Discriminant Analyses

The taxonomic status of Euphrasia borealis, E. nemorosa, and E. stricta in eastern North America has been the subject of considerable controversy. A sample of 184 operational taxonomic units were scored for 58 morphological characters, and the resulting data matrix was subjected to cluster and principal component analyses. Two groups were recognized on the basis of bract and upper cauline leaf characters and designated as E. nemorosa and E. stricta. These two groups were then subjected to several discriminant analyses (stepwise, linear, and canonical) using quantitative data. The results do not support the recognition of E. borealis and E. nemorosa as separate taxa. These plants should be treated as a single species, for which the correct name is E. nemorosa. Euphrasia stricta is, however, morphologically distinct from E. nemorosa. Some geographic differentiation was observed between plants of E. nemorosa from Newfoundland and those from Quebec, but not enough to warrant the recognition of infraspecific taxa. No evidence of hybridization between E. nemorosa and E. stricta was found. Key words: Euphrasia borealis, Euphrasia nemorosa, Euphrasia stricta, numerical analysis, North America, hybridization.

Aristolochia longeracemosa, a new synonym of A. chlamydophylla (Aristolochiaceae)

Phytotaxa ◽  
2017 ◽  
Vol 317 (1) ◽  
pp. 76
Author(s):  
TRUONG VAN DO ◽  
XIN-FEN GAO
Keyword(s):  
Southern China ◽  
Taxonomic Status ◽  
Detailed Comparison ◽  
Morphological Characters ◽  
Type Specimens ◽  
Worldwide Distribution ◽  
New Synonym ◽  
Flora Of China ◽  
Flora Of Thailand ◽  
High Degree

Aristolochia Linnaeus (1753: 960) (Aristolochiaceae) comprises about 500 species. The genus has worldwide distribution (Wanke et al. 2006). Recent findings of Aristolochia (Phuphathanaphong 2006, Xu et al. 2011, Huong et al. 2014, Do et al. 2015, Wu et al. 2015), together with the previous treatments for the Flora of Thailand (Phuphathanaphong 1987), the Flora of Vietnam (Pham 2000) and the Flora of China (Huang et al. 2003) confirmed the Thai & Indo-Chinese floristic region as a center of diversity for Aristolochia, with currently about 90 species. A high degree of endemism is found for specific countries (Huang et al. 2003, Phuphathanaphong 2006). However, the delimitation and taxonomic status of some species are still unclear due to limited access to specimen databases, especially for the type specimens in those countries. Notably, recent studies have significantly revised the taxonomic status of several previously described Aristolochia species when herbarium materials from multiple countries in the region were consulted (Do et al. 2014, Do 2016, Zu et al. 2016). On the basis of the examination of the protologue, the type specimens, and recent collections from the herbaria BKF, C, GXMI, HITBC, IBSC, KUN, PE and PEM, we conclude that Aristolochia longeracemosa B. Hansen & Leena Phuphathanaphong (1999: 557), described from collections made in northern Thailand, is conspecific with A. chlamydophylla C.Y. Wu ex S. M. Hwang (1981: 223) from southern China. Hence, we here propose the former as a new synonym of the latter. A detailed comparison of the morphological characters and habitat of these two species is provided.

Taxonomic assessment and distribution of common toads (Bufo bufo and B. verrucosissimus) in Turkey based on morphological and molecular data

2020 ◽  
Vol 41 (3) ◽  
pp. 399-411
Author(s):  
Nurhayat Özdemir ◽  
Cantekin Dursun ◽  
Nazan Üzüm ◽  
Bilal Kutrup ◽  
Serkan Gül
Keyword(s):  
Nuclear Dna ◽  
Sequence Data ◽  
Phylogenetic Analyses ◽  
Taxonomic Status ◽  
Morphological Characters ◽  
Molecular Data ◽  
Bufo Bufo ◽  
Species Group ◽  
Morphological Data ◽  
Western Palearctic

Abstract The Bufo bufo species group includes four species distributed in the western Palearctic: B. bufo, B. eichwaldii, B. spinosus and B. verrucosissimus. Both B. bufo and B. verrucosissimus are known to occur in Turkey, but their range boundaries and the taxonomic status of B. verrucosissimus are still uncertain. In this study, we analyzed the variation in a set of morphological characters and in two mitochondrial and two nuclear DNA markers to address these questions. Phylogenetic analyses of sequence data support two main clades of common toads in Turkey, corresponding to B. bufo and B. verrucosissimus. The latter is subdivided into two allopatric subclades including populations along the Mediterranean and Black Sea coast, respectively. Discriminant analysis of morphological data showed separation among groups as defined by molecular analyses. We discuss these results and their implications for the evolutionary history of common toads in Turkey.

scholarly journals Monophyly of Heterandriini (Teleostei: Poeciliidae) revisited: a critical review of the data

2012 ◽  
Vol 10 (1) ◽  
pp. 19-44 ◽  
Author(s):  
Alfy Morales-Cazan ◽  
James S. Albert
Keyword(s):  
Biological Sciences ◽  
Morphological Characters ◽  
Model Systems ◽  
Morphological Data ◽  
Maximum Parsimony Analysis ◽  
Fin Ray ◽  
Outgroup Species ◽  
Tree Topologies ◽  
Tree Resolution ◽  
Shape Morphometrics

The systematics and taxonomy of poeciliid fishes (guppies and allies) remain poorly understood despite the relative importance of these species as model systems in the biological sciences. This study focuses on testing the monophyly of the nominal poeciliine tribe Heterandriini and the genus Heterandria, through examination of the morphological characters on which the current classification is based. These characters include aspects of body shape (morphometrics), scale and fin-ray counts (meristics), pigmentation, the cephalic laterosensory system, and osteological features of the neurocranium, oral jaws and suspensorium, branchial basket, pectoral girdle, and the gonopodium and its supports. A Maximum Parsimony analysis was conducted of 150 characters coded for 56 poeciliid and outgroup species, including 22 of 45 heterandriin species (from the accounted in Parenti & Rauchenberger, 1989), or seven of nine heterandriin species (from the accounted in Lucinda & Reis, 2005). Multistate characters were analyzed as both unordered and ordered, and iterative a posteriori weighting was used to improve tree resolution. Tree topologies obtained from these analyses support the monophyly of the Middle American species of "Heterandria," which based on available phylogenetic information, are herein reassigned to the genus Pseudoxiphophorus. None of the characters used in previous studies to characterize the nominal taxon Heterandriini are found to be unambiguously diagnostic. Some of these characters are shared with species in other poeciliid tribes, and others are reversed within the Heterandriini. These results support the hypothesis that Pseudoxiphophorus is monophyletic, and that this clade is not the closest relative of H. formosa (the type species) from southeastern North America. Available morphological data are not sufficient to assess the phylogenetic relationships of H. formosa with respect to other members of the Heterandriini. The results further suggest that most tribe-level taxa of the Poeciliinae are not monophyletic, and that further work remains to resolve the evolutionary relationships of this group.

scholarly journals An assessment of the taxonomic validity of three species of marsupial frogs (Anura: Hemiphractidae: Gastrotheca) from the Yungas of Bolivia based on external morphology and cranial osteology

Zootaxa ◽  
2021 ◽  
Vol 5068 (2) ◽  
pp. 211-239
Author(s):  
CLAUDIA LANSAC ◽  
RODRIGO AGUAYO ◽  
IGNACIO DE LA RIVA
Keyword(s):  
Principal Component ◽  
Taxonomic Status ◽  
Ct Scanning ◽  
Developmental State ◽  
Morphological Characters ◽  
Biological Entity ◽  
Nominal Species ◽  
Linear Discriminant ◽  
Morphological Studies ◽  
Cranial Osteology

The genus Gastrotheca (Anura: Hemiphractidae) is a group of marsupial frogs particularly diverse in Andean regions. Several taxonomic studies of this genus have been conducted in the humid cloud forests—or Yungas—of the Andean eastern slopes of central Bolivia (departments of Cochabamba and Santa Cruz). Yet, the distinction among three species that occur sympatrically in these forests, G. lauzuricae (proposed as a junior synonym of G. coeruleomaculatus in 2015), G. piperata, and G. splendens, remains unclear since the morphological characters that purportedly support their differentiation are variable and partly shared among them. We have carried out external morphological studies, including multivariate morphometric analyses, to assess how they support the taxonomic status of these three species. We also evaluated characters of the cranial osteology of a sample of six individuals using micro CT-scanning. Principal component and linear discriminant analyses resulted in a great overlap among the putative species. Cranial osteological comparisons did not reveal highly significant differences among them, but suggested that different degrees of hyperossification could be related to the developmental state of individuals. Our results indicate that most morphological and osteological reported differences between the three species likely represent intraspecific variation. Thus, we propose that the three nominal species belong to a single biological entity, for which the name Gastrotheca splendens (Schmidt, 1857) has priority. We also restrict the name Gastrotheca coeruleomaculatus (Werner, 1899) to externally similar congeneric populations from the Yungas forests of department of La Paz, but highlighting the need of a detailed evaluation of their taxonomic identity.  

scholarly journals Morphological and genetic diversity of Senecio vulgaris L. (Asteraceae) in Iran

2021 ◽  
Vol 80 (2) ◽  
Author(s):  
Mostafa Ebadi ◽  
Rosa Eftekharian
Keyword(s):  
Genetic Diversity ◽  
Principal Component ◽  
Morphological Characters ◽  
Mantel Test ◽  
Morphological Data ◽  
Principal Coordinates Analysis ◽  
Cauline Leaf ◽  
Senecio Vulgaris ◽  
Molecular Features ◽  
Principal Coordinates

Senecio vulgaris L., an annual herb belonging to the Asteraceae, is widely distributed in different regions of the world. There is no information on the intraspecific variations of the morphological and molecular features of this species. In the present investigation, we studied the morphological and genetic diversity of 81 accessions of S. vulgaris collected from 10 geographical populations. Eleven inter simple sequence repeat (ISSR) primers were used for the examination of genetic variations among the populations. Analysis of molecular variance (AMOVA) and GST analyses revealed significant differences among the investigated populations. A significant correlation between genetic distance and geographical distance was revealed by the Mantel test. However, reticulation analysis indicated the occurrence of gene flow among most of the populations studied. Principal component analysis (PCA) plot showed that the number of capitula, length of the cauline leaf and plant height were the most variable morphological characters. Principal coordinates analysis (PCoA) plot revealed two groups of populations, according to molecular and morphological data. The results suggested the existence of possible intraspecific taxonomic ranks within this species.

Taxonomy, natural history, and conservation of the Great-billed Seed-Finch Sporophila maximiliani (Cabanis, 1851) (Thraupidae, Sporophilinae)

Zootaxa ◽  
2018 ◽  
Vol 4442 (4) ◽  
pp. 551 ◽  
Author(s):  
FLÁVIO KULAIF UBAID ◽  
LUÍS FABIO SILVEIRA ◽  
CESAR A. B. MEDOLAGO ◽  
THIAGO V. V. COSTA ◽  
MERCIVAL ROBERTO FRANCISCO ◽  
...  
Keyword(s):  
Natural History ◽  
South America ◽  
Captive Breeding ◽  
Conservation Status ◽  
Bird Species ◽  
Principal Component ◽  
Taxonomic Status ◽  
Morphological Characters ◽  
Morphometric Characters ◽  
History Of

Seed-finches are small-sized Neotropical granivorous birds characterized by extremely strong and thick beaks. Among these birds, the Great-billed Seed-Finch Sporophila maximiliani has been selectively and intensively trapped to the extent that has become one of the most endangered bird species in South America, yet its taxonomy remains complex and controversial. Two subspecies have been recognized: S. m. maximiliani (Cabanis, 1851), mainly from the Cerrado of central South America, and S. m. parkesi Olson (= Oryzoborus m. magnirostris), from northeastern South America. Originally, S. m. parkesi was diagnosed as being larger than the Large-billed Seed-Finch, S. c. crassirostris (Gmelin, 1789), but proper comparisons with S. m. maximiliani, which is larger than S. c. crassirostris, were never performed. Here we provide a review of the taxonomic and nomenclatural history of S. maximiliani, reevaluate the validity and taxonomic status of the subspecies based on morphological characters, and significantly revise its geographic distribution. Analyses based on plumage patterns and a Principal Component Analysis of morphometric characters indicated that S. m. parkesi is most appropriately treated as a synonym of the nominate taxon, which results in a monotypic S. maximiliani comprising two disjunct populations. Further, we conducted systematic searches for S. maximiliani in Brazil, in an attempt to obtain natural history information. After more than 6,000 hours of fieldwork in 45 areas of potential and historical occurrence, S. maximiliani was located only in two sites, in marshy environments called veredas, confirming the critical conservation status of this species, at least in Brazil. We discuss the conservation potential for, and the problems involved with, captive breeding of S. maximiliani for reintroduction into the wild. 

scholarly journals A Systematic Analysis of the Alpine Saxifrage Complex (Saxifragaceae) in the Canadian Arctic Islands Using Morphology and Chloroplast DNA Data

2004 ◽  
Vol 118 (3) ◽  
pp. 326 ◽  
Author(s):  
Caroline Healy ◽  
Lynn J. Gillespie
Keyword(s):  
Morphological Variability ◽  
Canadian Arctic ◽  
Principal Component ◽  
Distinct Species ◽  
Morphological Characters ◽  
Sympatric Species ◽  
Sensu Stricto ◽  
Morphological Data ◽  
Systematic Analysis ◽  
Site Analysis

The Saxifraga nivalis complex displays significant ecological, morphological and cytological variation. Most European studies suggest that the S. nivalis complex comprises two distinct species: Saxifraga nivalis sensu stricto and Saxifraga tenuis. However, the presence of intermediate morphotypes, inconsistencies in chromosomal counts and variability in morphological keys and descriptions have led to different taxonomic interpretations of the complex in North America. This study investigated the systematics of Canadian Arctic Island members of this complex from 157 specimens using 23 morphological characters. Principal component analysis of the morphological data revealed two adjacent clusters, corresponding to the two taxa and consistent with a close morphological similarity and the presence of hybrids. A preliminary restriction site analysis of five non-coding regions of the chloroplast genome, trnH-trnK, trnT-trnF, trnF-trnV, trnV-rbcL and rbcL-ORF106, was conducted using 21 restriction endonucleases. This analysis indicated a length difference between the trnT-trnF region of S. nivalis and that of S. tenuis, but no difference in restriction sites for any of the assayed regions. These results confirm that in the Canadian Arctic, the S. nivalis complex consists of two closely related, largely sympatric species, with notable morphological variability, and possible hybrids.

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