Lack of morphological differentiation in eastern (Rhinichthys atratulus) and western (Rhinichthys obtusus) blacknose dace in Canada

2005 ◽  
Vol 83 (11) ◽  
pp. 1502-1509 ◽  
Author(s):  
B A Fraser ◽  
N E Mandrak ◽  
R L McLaughlin
Keyword(s):  
Multivariate Analyses ◽  
Morphological Differentiation ◽  
Morphological Characters ◽  
Sympatric Populations ◽  
Diagnostic Characters ◽  
Allopatric Populations ◽  
Rhinichthys Atratulus ◽  
Blacknose Dace ◽  
Morphological Differences ◽  
Colouration Pattern

We tested whether eastern (Rhinichthys atratulus (Herman, 1804)) and western (Rhinichthys obtusus Agassiz, 1854) blacknose dace could be differentiated in Canada. Eastern, western, and southern forms of blacknose dace had been considered subspecies until recently, when separation of eastern and western species was accepted (J.S. Nelson et al. 2004. Am. Fish. Soc. Spec. Publ. No. 29). However, no study has examined morphological differences in purported diagnostic characters between the two species in Canada. Mensural, meristic, and colouration pattern characters purported to distinguish the two species were measured for blacknose dace across their Canadian range, including likely zones of sympatry. Univariate and multivariate analyses of morphological characters could not distinguish between individuals in allopatric populations from eastern and western regions. Variation among individuals within sympatric populations did not differ significantly from the variation among individuals within allopatric populations, providing no evidence of divergence of the species in sympatry. The delineation of eastern and western species using morphology is not supported by this study, given the lack of differentiation in key distinguishing characters within the Canadian range of the species.

scholarly journals Intra- and interspecific morphological variation in sympatric and allopatric populations of Mustela putorius and M. eversmanii (Carnivora: Mustelidae) and detection of potential hybrids

2020 ◽  
Author(s):  
Tamás Cserkész ◽  
Csaba Kiss ◽  
Zoltán Barkaszi ◽  
Tamás Görföl ◽  
Igor Zagorodniuk ◽  
...  
Keyword(s):  
Pannonian Basin ◽  
Morphological Differentiation ◽  
Morphological Characters ◽  
Cranial Morphology ◽  
Mustela Putorius ◽  
Sympatric Populations ◽  
Representative Sampling ◽  
Allopatric Populations ◽  
Morphometric Analyses ◽  
Cranial Measurements

Abstract European mustelids include the European polecat, Mustela putorius, and the steppe polecat, M. eversmanii. Both occur sympatrically in the Pannonian Basin, where M. eversmanii hungarica represents the westernmost part of the latter species and they allegedly hybridize. We investigated the morphological relationships in sympatric and allopatric populations of these mustelids with representative sampling, taxonomic and geographic coverage. We evaluated inter- and intraspecific patterns of morphological differentiation of 20 cranial measurements and four external traits by distance-based morphometric approaches and multivariate analyses. Our results revealed a considerable heterogeneity in cranial morphology. The two species appeared to be clearly differentiated although sympatric populations were closer to each other and had a slight overlap in the morphometric space. Within M. eversmanii, the subspecies and the nominal taxon only partially overlapped, and M. eversmanii eversmanii was more distant from M. putorius than subspecies hungarica. Although morphometric analyses revealed several intermediate individuals in size in sympatric M. eversmanii and M. putorius populations, only a small fraction of such specimens showed conflict in discrete morphological characters with the diagnostic discriminant function. We interpret these results as an indication of ongoing hybridisation between sympatric populations, but the low number of hybrids identified suggests limited genetic exchange between the species.

Geographic variability and taxonomy of the nose-horned viper, Vipera ammodytes (L. 1758), in the central and eastern parts of the Balkans: A multivariate study

2003 ◽  
Vol 24 (3) ◽  
pp. 359-377 ◽  
Author(s):  
Georg Džukić ◽  
Ljiljana Tomović
Keyword(s):  
Multivariate Analyses ◽  
Morphological Differentiation ◽  
Balkan Peninsula ◽  
Morphological Characters ◽  
Geographic Variability ◽  
The Balkans ◽  
Multivariate Study ◽  
Yugoslav Republic ◽  
North Western ◽  
Vipera Ammodytes

AbstractA multivariate analyses of various morphological characters (morphometric, meristic and qualitative) of nose-horned viper (Vipera ammodytes) revealed a complex morphological differentiation of populations from the central and the eastern Balkan Peninsula. Analyses of quantitative data showed no clear morphological discrimination or well-defined taxonomical units. On the contrary, analyses of qualitative traits separated two discrete taxa in the analysed area. One, inhabiting the eastern and the southern part of the Balkans, includes samples from most parts of Bulgaria, Former Yugoslav Republic of Macedonia and south-eastern Serbia, whereas the other ranges from north-western Bulgaria through the main part of Serbia (except the south-east) to Montenegro.

Genetic and Morphological Differentiation between Dwarf and Normal Size Forms of Lake Whitefish (Coregonus clupeafotmis) in Como Lake, Ontario

1993 ◽  
Vol 50 (1) ◽  
pp. 210-216 ◽  
Author(s):  
J. A. Vuorinen ◽  
R. A. Bodaly ◽  
J. D. Reist ◽  
L. Bernatchez ◽  
J. J. Dodson
Keyword(s):  
Morphological Characteristics ◽  
Morphological Differentiation ◽  
Principal Component ◽  
Lake Ontario ◽  
Glacial Refugia ◽  
Lake Whitefish ◽  
Sympatric Populations ◽  
Allopatric Divergence ◽  
Significant Difference ◽  
Morphological Differences

Normal and dwarf size forms of lake whitefish (Coregonus clupeaformis) from Como Lake, Ontario, were sampled at spawning time and examined for differences in electrophoretic, mtDNA, and morphological characteristics to test the hypothesis of reproductive isolation and provide clues regarding evolutionary origin. Of the 36 enzyme loci examined, 33 were fixed for the same alleles in both dwarf and normal lake whitefish. At the three polymorphic loci, allele frequencies were not statistically different between dwarfs and normals. mtDNA analysis revealed five different haplotypes. The same mtDNA haplotype was the most common in both dwarf and normal lake whitefish, but there was a statistically significant difference in haplotype frequencies between the two size forms. Discriminant and principal component analyses demonstrated highly significant morphological differences between dwarfs and normals. Because the two size morphs spawn in the same place at the same time, it is most likely that genetic differences, not different rearing environments, underly the observed morphological differences. mtDNA haplotypes derived from both the Mississippi and Atlantic glacial refugia are present in Como Lake lake whitefish, raising the possibility of an allopatric divergence for the two forms; however, this hypothesis requires testing by genetic comparisons of other sympatric populations in Ontario.

scholarly journals Morphological characters and SNP markers suggest hybridization and introgression in sympatric populations of the pleurocarpous mosses Homalothecium lutescens and H. sericeum

2020 ◽  
Vol 20 (4) ◽  
pp. 619-637
Author(s):  
Weerachon Sawangproh ◽  
Annick S. Lang ◽  
Lars Hedenäs ◽  
Nils Cronberg
Keyword(s):  
Morphological Characters ◽  
Snp Markers ◽  
Transcriptome Data ◽  
Sympatric Populations ◽  
Future Studies ◽  
Evolutionary Diversification ◽  
Allopatric Populations ◽  
Intermediate Morphology ◽  
Pleurocarpous Mosses

AbstractHybridization in bryophytes involves a fusion of gametes produced by haploid parental gametophytes of different species. The primary hybrid is thus the short-lived diploid sporophyte, which soon undergoes meiosis prior to the formation of large amounts of haploid spores. We compared morphology of gametophytes (branch leaves) and sporophytes (capsule inclination) from sympatric populations and allopatric populations of H. lutescens and H. sericeum. In addition, we used transcriptome data to select 85 nuclear SNP markers that were fixed for alternative alleles in the two species. The SNPs were used to estimate the degree of hybridization in diploid sporophytes. Our study shows that gametophytes from sympatric populations display intermediate morphology in a number of leaf characters, with exception for leaf sizes, which are markedly smaller than those in allopatric populations. None of the 100 sporophytes appeared to be primary hybrids, but 33 displayed admixing—heterozygotic expression of SNP markers or mismatch of occasional markers in homozygous condition—suggesting that extensive introgression takes place in the sympatric populations. Most sporophytes with intermediate capsule inclination, initially classed as putative hybrids, did not display admixture of nuclear SNP markers. Sixty-seven percent of admixed sporophytes have predominantly nuclear SNPs typical for H. lutescens. Our results suggest that interspecific hybridization and bidirectional introgression are relatively common in the studied sympatric populations, giving rise to viable recombinants, but not complete mixing of the parental genomes. Our study is one of the first detailed accounts of hybridization among pleurocarpous mosses, opening for future studies of gene transfer and introgression between bryophyte lineages and its role in local adaptation and long-term evolutionary diversification.

A new species of Contomastix (Squamata, Teiidae) supported by total evidence, with remarks on diagnostic characters defining the genus

2019 ◽  
pp. 23-36
Author(s):  
Mario. R. Cabrera
Keyword(s):  
New Species ◽  
Geographic Distribution ◽  
Phylogenetic Reconstruction ◽  
Total Evidence ◽  
Molecular Evidence ◽  
Proximal Margin ◽  
Diagnostic Characters ◽  
Morphological Differences ◽  
A New Species ◽  
Molecular Characters

Formerly Cnemidophorus was thought to be the most speciose genus of Teiidae. This genus comprised four morphological groups that were later defined as four different genera, Ameivula, Aurivela, Cnemidophorus and Contomastix. The last appears as paraphyletic in a recent phylogenetic reconstruction based on morphology, but monophyletic in a reconstruction using molecular characters. Six species are allocated to Contomastix. One of them, C. lacertoides, having an extensive and disjunct geographic distribution in Argentina, Uruguay and Brazil. Preliminary analyses revealed morphological differences among its populations, suggesting that it is actually a complex of species. Here, we describe a new species corresponding to the Argentinian populations hitherto regarded as C. lacertoides, by integrating morphological and molecular evidence. Furthermore, we demonstrate that the presence of notched proximal margin of the tongue is a character that defines the genus Contomastix.

Integrative taxonomic and geographic variation analyses in Cyrtodactylus aequalis (Squamata: Gekkonidae) from southern Myanmar (Burma): one species, two different stories

2020 ◽  
Vol 66 (3-4) ◽  
pp. 151-179
Author(s):  
L. Lee Grismer ◽  
L. Wood Perry ◽  
Marta S. Grismer ◽  
Evan S.H. Quah ◽  
Myint Kyaw Thura ◽  
...  
Keyword(s):  
Geographic Variation ◽  
Evolutionary History ◽  
Phylogenetic Inference ◽  
Morphological Characters ◽  
Molecular Data ◽  
Biodiversity Crisis ◽  
Allopatric Populations ◽  
Compelling Argument ◽  
Historical Accuracy ◽  
Molecular Phylogenetic

The historical accuracy of building taxonomies is improved when they are based on phylogenetic inference (i.e., the resultant classifications are less apt to misrepresent evolutionary history). In fact, taxonomies inferred from statistically significant diagnostic morphological characters in the absence of phylogenetic considerations, can contain non-monophyletic lineages. This is especially true at the species level where small amounts of gene flow may not preclude the evolution of localized adaptions in different geographic areas while underpinning the paraphyletic nature of each population with respect to the other. We illustrate this point by examining genetic and morphological variation among three putatively allopatric populations of the granite-dwelling Bent-toed Gecko Cyrtodactylus aequalis from hilly regions in southeastern Myanmar. In the absence of molecular phylogenetic inference, a compelling argument for three morphologically diagnosable species could be marshaled. However, when basing the morphological analyses of geographic variation on a molecular phylogeny, there is a more compelling argument that only one species should be recognized. We are cognizant of the fact however, that when dealing with rare species or specimens for which no molecular data are possible, judicious morphological analyses are the only option—and the desired option given the current worldwide biodiversity crisis.

Between- and within-breed morphological variability in Moroccan sheep breeds

2016 ◽  
Vol 58 ◽  
pp. 91-100 ◽  
Author(s):  
I. Boujenane ◽  
D. Petit
Keyword(s):  
Multivariate Analyses ◽  
Morphological Variability ◽  
Tail Length ◽  
Morphological Characterization ◽  
Total Variance ◽  
High Association ◽  
Sheep Breeds ◽  
Selection Strategies ◽  
Morphological Differences

SummaryThe objective of this study was a morphological characterization of five Moroccan sheep breeds (Béni Guil, Boujaâd, D'man, Sardi and Timahdite) to assess between- and within-breed variability using multivariate analyses. Fourteen morphological measurements were collected on 876 adult animals of both sexes in 98 different flocks located in 22 geographic localities of five breeds. The multiple analysis of variance revealed that significant morphological differences existed between breeds. The overall proportion of total variance due to between-breed component was 28.3 percent. The factor analysis revealed three factors accounting for 50.1, 11.8 and 7.54 percent of total variance. The first factor had high loadings for variables relating to body size, whilst the second factor had high association with traits reflecting tail length and ear size. The third factor had high loadings for wool trait. The squared Mahalanobis distance between the five sheep breeds were highly significant (P< 0.001). The largest morphological divergence was shown between Béni Guil and Sardi breeds (23.5) and the smallest one was between Boujaâd and Sardi breeds (3.54). The discriminant functions clearly discriminated and assigned 94.4 percent of Béni Guil, 79.7 of Boujaâd, 88.5 percent of D'man, 86.7 of Sardi and 80.1 percent of Timahdite sheep into their breed of origin. Overall morphological differences observed within-breeds were due for 18.1 percent to geographic locality and for 20.7 percent to flock management. It was concluded that the information reported in this study will be the basis for the establishment of characterization and selection strategies for Moroccan sheep.

Phylogenetic relationships between the genera Aphidius and Lysaphidus (Hymenoptera: Braconidae: Aphidiinae) with description of Aphidius iranicus sp. nov.

2007 ◽  
Vol 139 (3) ◽  
pp. 297-307 ◽  
Author(s):  
Željko Tomanović ◽  
Ehsan Rakhshani ◽  
Petr Starý ◽  
Nickolas G. Kavallieratos ◽  
Ljubiša Ž. Stanisavljević ◽  
...  
Keyword(s):  
Phylogenetic Relationships ◽  
Morphological Characters ◽  
Taxonomic Position ◽  
Parsimony Analysis ◽  
Parasitoid Species ◽  
Consensus Tree ◽  
Artemisia Absinthium ◽  
Diagnostic Characters ◽  
Line Drawings ◽  
Generic Status

AbstractWe analyzed the phylogenetic relationships between eight Aphidius Nees and six Lysaphidus Smith species on the basis of 12 morphological characters by parsimony analysis. The consensus tree does not support the generic status of Lysaphidus. Aphidius iranicus, sp. nov., associated with Titanosiphon bellicosum Nevsky on Artemisia absinthium L. from Iran, is described. The new parasitoid species is described and illustrated by line drawings, and its diagnostic characters are discussed. The taxonomic position of the subgenus Tremblayia Tizado and Núñez-Pérez is also considered. Tremblayia and Lysaphidus are newly classified as synonyms of Aphidius. The following new or revised combinations are proposed: Aphidius adelocarinus Smith, comb. rev., A. ramythirus Smith, comb. rev., A. rosaphidis Smith, comb. rev., A. viaticus (Sedlag), comb. nov., A. arvensis (Starý), comb. nov., and A. erysimi (Starý), comb. nov.

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