New characters for species discrimination within the genus Prolagus (Ochotonidae, Lagomorpha, Mammalia)

The genus Prolagus is very common in the Neogene and Quaternary of Europe, western Asia and northern Africa. However, the complexity of its systematics, mainly based on p3 characters that show great inter- and intraspecific variability, led to an under-utilization of Prolagus in biochronology and palaeogeography studies. A re-analysis of the species of Prolagus recorded in the Escobosa de Calatañazor karst fissure fillings (Duero Basin, northern Spain, MN7/8, late Middle Miocene) includes the introduction of new maxillary and mandibular morphological characters (position, shape and size of premolar and mandibular foramina) and new dental measurements (hypoflexus depth, distal hypercone length, and partial width of upper premolars; relative length of trigonid of lower molariform teeth) to be used for species discrimination within the genus Prolagus. The new morphological characters and measurements introduced in this paper allow for a more accurate taxonomic assignment of Prolagus species, thus improving the estimation of faunal palaeodiversity, detection of sympatric species and taphonomic mixing, and contributing to more reliable biochronological, palaeogeographical, and phylogenetic inferences based on Prolagus.

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Intraspecific variability of morphological characters in the species-rich deep-sea genus Acantholaimus Allgén, 1933 (Nematoda: Chromadoridae)

Nematology ◽

10.1163/15685411-00002970 ◽

2016 ◽

Vol 18 (4) ◽

pp. 455-473 ◽

Cited By ~ 6

Author(s):

Dmitry M. Miljutin ◽

Maria A. Miljutina

Keyword(s):

Deep Sea ◽

Intraspecific Variability ◽

Morphological Characters ◽

Molecular Data ◽

Species Discrimination ◽

Species Differentiation ◽

Lateral Field ◽

Operational Taxonomic Units ◽

General Arrangement ◽

Taxonomic Approach

Acantholaimusis a species-rich genus of deep-sea nematodes, often with dozens of species found at the same locality but each represented by single or few individuals. Species discrimination by morphological characters in this genus is therefore often difficult due to transitional forms that may be referred to several species because of lack of data on intraspecific variability. The aim of this study was to evaluate the intraspecific variability of morphological characters that are most often used inAcantholaimustaxonomy, in order to distinguish those which are most informative for species differentiation. A reverse taxonomic approach was applied for initial species discrimination. Two loci, one each from small and large subunits of rRNA, were sequenced for 59Acantholaimusspecimens from two deep-sea locations. Twenty-seven Molecular Operational Taxonomic Units (MOTU) were identified, of which 12 were represented by more than one individual. These were then analysed for intraspecific variability in morphological characters. Some of the examined characters showed high intraspecific variability; specifically: length of cephalic setae; distance from anterior end to amphid; shape of anterior setae; position and arrangement of cervical setae. In the absence of genetic data, these characters should be used with caution for differential diagnoses or species discrimination. Other characters were more conservative within the same MOTU: body proportions; length of outer labial setae; amphidial diam.; appearance of lateral field; general arrangement of cervical setae; and shape of tail. These characters may be successfully used for species discrimination in the absence of molecular data.

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Unravelling the hidden biodiversity – the establishment of DNA barcodes of fish-parasitizing Acanthocephala Koehlreuther, 1771 in view of taxonomic misidentifications, intraspecific variability and possible cryptic species

Parasitology ◽

10.1017/s0031182020001316 ◽

2020 ◽

Vol 147 (13) ◽

pp. 1499-1508

Author(s):

Susanne Reier ◽

Helmut Sattmann ◽

Thomas Schwaha ◽

Hans-Peter Fuehrer ◽

Elisabeth Haring

Keyword(s):

Cryptic Species ◽

Dna Barcoding ◽

Intraspecific Variability ◽

Morphological Characters ◽

Species Level ◽

Morphological Identification ◽

Dna Barcodes ◽

Taxonomic Assignment ◽

Obligate Parasites ◽

Intraspecific Variations

AbstractAcanthocephalans are obligate parasites of vertebrates, mostly of fish. There is limited knowledge about the diversity of fish-parasitizing Acanthocephala in Austria. Seven determined species and an undetermined species are recorded for Austrian waters. Morphological identification of acanthocephalans remains challenging due to their sparse morphological characters and their high intraspecific variations. DNA barcoding is an effective tool for taxonomic assignment at the species level. In this study, we provide new DNA barcoding data for three genera of Acanthocephala (Pomphorhynchus Monticelli, 1905, Echinorhynchus Zoega in Müller, 1776 and Acanthocephalus Koelreuter, 1771) obtained from different fish species in Austria and provide an important contribution to acanthocephalan taxonomy and distribution in Austrian fish. Nevertheless, the taxonomic assignment of one species must remain open. We found indications for cryptic species within Echinorhynchus cinctulus Porta, 1905. Our study underlines the difficulties in processing reliable DNA barcodes and highlights the importance of the establishment of such DNA barcodes to overcome these. To achieve this goal, it is necessary to collect and compare material across Europe allowing a comprehensive revision of the phylum in Europe.

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Morphology, nomenclature and distribution of Bassia monticola (Chenopodiaceae-Amaranthaceae), a poorly known species from Western Asia

Novitates Systematicae Plantarum Vascularium ◽

10.31111/novitates/2020.51.13 ◽

2020 ◽

pp. 13-17

Author(s):

A. P. Sukhorukov ◽

M. A. Kushunina

Keyword(s):

Molecular Phylogeny ◽

Morphological Characters ◽

Mountainous Regions ◽

Western Asia

Kochia monticola was previously considered as a synonym for the widely distributed Irano-Turanian Panderia pilosa. After the merger of Kochia and Panderia with Bassia based on molecular phylogeny, K. monticola remained a synonym of Bassia pilosa. We claim that Bassia monticola, a name proposed by Kuntze (1891) for K. monticola, should be separated from B. pilosa based on morphological characters and localised distribution in mountainous regions of Iran, Iraq, Syria, and Lebanon at altitudes 1800–2600 m a. s. l.

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The relative taxonomic value of morphological characters in the genus <i>Nummulites</i> (Foraminiferida)

Journal of Micropalaeontology ◽

10.1144/jm.11.2.197 ◽

1992 ◽

Vol 11 (2) ◽

pp. 197-209 ◽

Cited By ~ 6

Author(s):

Andrew Racey

Keyword(s):

Morphological Character ◽

Morphological Characters ◽

Species Discrimination ◽

Evolutionary Trends ◽

Ontogenetic Effects

Abstract. The main evolutionary trends in the nummulites are briefly summarised and the value of certain morphological characters in species discrimination are summarised. The degree of interdependence of each morphological character on all other characters is assessed and the characters are weighted in order of importance. Environmental and ontogenetic effects on each character are then reviewed and the characters reweighted in order of importance.

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Filling missing links in albuneid crab distributions (superfamily Hippoidea) in the Bay of Bengal, eastern Indian Ocean

Crustaceana ◽

10.1163/15685403-00003846 ◽

2018 ◽

Vol 91 (12) ◽

pp. 1495-1504 ◽

Cited By ~ 2

Author(s):

Rajan Kumar ◽

Shikha Rahangdale ◽

Subal Kumar Roul

Keyword(s):

Indian Ocean ◽

Bay Of Bengal ◽

Morphological Characters ◽

Eastern Indian Ocean ◽

Species Discrimination ◽

Gulf Of Mannar ◽

Fishing Gear ◽

Morphometric Characters ◽

First Time

Abstract Albuneid crabs are specialized and active sand-burrowing organisms. Despite their substantial diversity, their ability to avoid fishing gear leads to “under collection” and a discontinuous record of distribution. The present study documents the first distributional record of Albunea occulta Boyko, 2002 from the Bay of Bengal, eastern Indian Ocean. Albunea thurstoni Henderson, 1893 is also recorded for the first time from the area, i.e., from the Gulf of Mannar, southwestern Bay of Bengal. This study further reports variation in morphological characters, especially in the carapace grooves (CG) from previous records and across specimens from different regions. Morphometric characters were found useful in species discrimination, which is explained as well.

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On the diversity of the SE Indo-Pacific species ofTerebellides(Annelida; Trichobranchidae), with the description of a new species

PeerJ ◽

10.7717/peerj.2313 ◽

2016 ◽

Vol 4 ◽

pp. e2313 ◽

Cited By ~ 2

Author(s):

Julio Parapar ◽

Juan Moreira ◽

Daniel Martin

Keyword(s):

New Species ◽

Morphological Characteristics ◽

Relative Length ◽

Andaman Sea ◽

Species Discrimination ◽

Pacific Waters ◽

Routine Monitoring ◽

Different Types ◽

Pacific Species ◽

A New Species

The study of material collected during routine monitoring surveys dealing with oil extraction and aquaculture in waters off Myanmar (North Andaman Sea) and in the Gulf of Thailand, respectively, allowed us to analyse the taxonomy and diversity of the polychaete genusTerebellides(Annelida). Three species were found, namelyTerebellidescf.woolawa,Terebellides hutchingsaespec. nov.(a new species fully described and illustrated), andTerebellidessp. (likely a new species, but with only one available specimen). The new species is characterised by the combination of some branchial (number, fusion and relative length of lobes and papillation of lamellae), and thoracic (lateral lobes and relative length of notopodia) characters and is compared with all species described or reported in the SW Indo-Pacific area, as well as with those sharing similar morphological characteristics all around the world. The taxonomic relevance of the relative length of branchial lobes and different types of ciliature in branchial lamellae for species discrimination in the genus is discussed. A key to allTerebellidesspecies described in SE Indo-Pacific waters is presented.

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Morphological variability of Quercus robur L. leaf in Serbia

Genetika ◽

10.2298/gensr1702529b ◽

2017 ◽

Vol 49 (2) ◽

pp. 529-541

Author(s):

Branislava Batos ◽

Danijela Miljkovic ◽

Marko Perovic ◽

Sasa Orlovic

Keyword(s):

Leaf Area ◽

Analysis Of Variance ◽

Population Differentiation ◽

Quercus Robur ◽

Phenotypic Variability ◽

Morphological Variability ◽

Intraspecific Variability ◽

Morphological Characters ◽

Interpopulation Variability ◽

Intrapopulation Variability

This paper presents the results of a study dealing with leaf morphological variability of Quercus robur L. 148 trees were sampled from 5 population across Serbia and 17 morphological traits were assessed. Interpopulation variability was confirmed by the results of the analysis of variance (ANOVA). A statistically significant (p <0.05) effect of population was obtained for most of the studied morphological characters. Intrapopulation variability was confirmed by statistically significant tree effects for all of the studied leaf characters (all p < 0.05). The results of the multivariate analysis of variance (MANOVA) confirmed a significant population and tree share in the total phenotypic variability (all p <0.05). By applying the canonical discriminant analysis (CDA), the first discriminant function accounted for 63% of the variability between populations and the second accounted for 20% of the population variability. The leaf area (AREA), specific leaf area (SLA) and surface area to perimeter ratio (ARPE) had the greatest effect on population differentiation (CDA). It is assumed that different environmental conditions affect population differentiation and that high intrapopulation variability is due to intraspecific variability.

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Variations in genetic structure and male genitalia suggest recent lineage diversification in the Neotropical dung beetle complex Canthon cyanellus (Scarabaeidae: Scarabaeinae)

Biological Journal of the Linnean Society ◽

10.1093/biolinnean/blaa131 ◽

2020 ◽

Vol 131 (3) ◽

pp. 505-520

Author(s):

Janet Nolasco-Soto ◽

Mario E Favila ◽

Alejandro Espinosa De Los Monteros ◽

Jorge González-Astorga ◽

Gonzalo Halffter ◽

...

Keyword(s):

Genetic Structure ◽

Morphological Variation ◽

Male Genitalia ◽

Morphological Variability ◽

Dung Beetle ◽

Morphological Characters ◽

Taxonomic Assignment ◽

Morphometric Variation ◽

Evolutionary Forces ◽

Significant Genetic Structure

Abstract We analysed the genetic divergence and morphology of the aedeagus (i.e. phallobase and parameres) in Canthon cyanellus at different geographical levels. The results from both approaches were compared with the current taxonomic assignment of the C. cyanellus complex, which includes three subspecies. We found a high variation in all the morphological characters of the aedeagus in the populations analysed; the morphometric variation was not geographically structured, either by population or by region. The genealogical analysis indicates a significant genetic structure that does not match either the morphological variation in the male genitalia or the previous subspecific taxonomic classification. Our results suggest that the morphological variation of the aedeagus is seemingly not an isolating reproductive barrier and that the intra- and interpopulation morphological variability of the aedeagus in the C. cyanellus complex does not permit the division into several species. We suggest that other evolutionary forces, such as genetic drift and sexual selection, have influenced the evolution of the male genitalia and the incipient differentiation of this species complex.

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

The Canadian Field-Naturalist ◽

10.22621/cfn.v118i3.1 ◽

2004 ◽

Vol 118 (3) ◽

pp. 326 ◽

Cited By ~ 5

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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Cryptic Species Discrimination in Western Pine Beetle, Dendroctonus brevicomis LeConte (Curculionidae: Scolytinae), Based on Morphological Characters and Geometric Morphometrics

Insects ◽

10.3390/insects10110377 ◽

2019 ◽

Vol 10 (11) ◽

pp. 377

Author(s):

Osiris Valerio-Mendoza ◽

Jazmín García-Román ◽

Moises Becerril ◽

Francisco Armendáriz-Toledano ◽

Gerardo Cuéllar-Rodríguez ◽

...

Keyword(s):

Morphological Characters ◽

Canonical Variate ◽

Dendroctonus Brevicomis ◽

Group Differences ◽

Species Discrimination ◽

Geometric Morphometric ◽

Western Pine Beetle ◽

Principal Coordinates ◽

The Pacific ◽

Pine Beetle

The western pine beetle (WPB), Dendroctonus brevicomis LeConte, is a major mortality agent of pines in North America. A total of 706 adults of WPB from 81 geographical sites were analyzed with traditional and geometric morphometric methods to evaluate the variation of discrete and quantitative morphological characters with particular attention to the antenna, spermatheca, and seminal rod. Principal coordinates and canonical variate analyses supported three geographical groups in WPB: (1) West, from British Columbia to southern California along the Pacific coast, Idaho, and Montana; (2) East-SMOC, including Nevada, Utah, Colorado, Arizona, New Mexico, Texas, Chihuahua, and Durango; and (3) SMOR, including Coahuila, Nuevo Leon, and Tamaulipas. The pubescence length on the elytral declivity was a robust character for separating West specimens from the other groups. Additionally, the genitalia shape both female and male in dorsal view was a reliable character for discriminating among groups. Based on these results, which agree with genetic and chemical ecology evidence, we herein reinstate Dendroctonus barberi Hopkins (East-SMOC group) and remove it from synonymy with D. brevicomis (West group). Differences in the spermatheca and seminal rod shape of SMOR specimens suggest that these populations might be a different species from D. barberi and D. brevicomis.

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