Morphological and physiological (i.e., upper lethal temperatures) comparisons between Notropis cornutus (Mitchell) and Notropis chrysocephalus (Rafinesque) from the Grand River, Ontario

1980 ◽  
Vol 58 (11) ◽  
pp. 2096-2101
Author(s):  
Edward Kott ◽  
Robert W. McCauley ◽  
Gregory Humphreys

Two forms of the Notropis cornutus (Luxilus) complex occur syntopically in the Grand River system. These have been interpreted by some authors as separate species and by others as subspecies. The forms can be distinguished morphologically by the number of predorsal scales and by pigmentation pattern. It has also been suggested that the upper lethal temperatures of the two differ.This is the first report of a study of these features in syntopic populations. The results indicate that neither physiological nor morphological characters can establish the taxonomic status of these forms and that what is needed is a detailed study of the breeding behaviour of these forms in areas of syntopy.

Author(s):  
K. Johannesson ◽  
B. Johannesson

In a short communication Grahame et al. (1992) argue against our finding that Littorina neglecta Bean is an ecotype of Littorina saxatilis (Olivi) rather than a separate species (Johannesson & Johannesson, 1990b). Unfortunately, Grahame et al. (1992) have miss-represented our earlier paper, and we feel the need to refute their arguments.In populations from north-western Europe we studied morphological characters used to separate Littorina neglecta from L. saxatilis. We found that intermediate shapes were common and, furthermore, we found no close coupling among characters used to define L. neglecta (Johannesson & Johannesson, 1990a). We further analysed the genetic variation in five strongly polymorphic allozyme loci. In four loci we found a pattern that indicated that L. neglecta is not reproductively isolated from L. saxatilis. In the fifth locus, Aat-1, we found consistent differences between populations of L. neglecta (from the low shore) and L. saxatilis (from the high shore). Similar differences were observed between low and high shore populations in Sweden where, however, no snails of neglecta-type were present.


2018 ◽  
Author(s):  
Günter Vogt ◽  
Nathan J. Dorn ◽  
Michael Pfeiffer ◽  
Chris Lukhaup ◽  
Bronwyn W. Williams ◽  
...  

ABSTRACTThe marbled crayfish is the only obligately parthenogenetic decapod crustacean and a novel research model and invasive animal on three continents. It is regarded either as a parthenogenetic form of slough crayfish Procambarus fallax or as a separate species named Procambarus virginalis. In order to investigate the species question of this unusual crayfish in detail we have identified the similarities and differences in morphology, life history, genetics, behaviour, ecology and biogeography between marbled crayfish and its most likely parent species P. fallax. We have investigated specimens from natural habitats, laboratory colonies and museum collections and performed a meta-analysis of our data and published data. Our COI based molecular tree with 27 Cambaridae confirms closest relationship of marbled crayfish with P. fallax. Marbled crayfish and P. fallax are similar with respect to morphological characters, coloration and body proportions, but differ considerably with respect to body size, fertility and longevity. The mitochondrial genes of both crayfish are similar, but ploidy level and haploid genome size are markedly different. Both crayfish are eurytopic and have two major annual recruitment periods, but marbled crayfish show different population structure and higher invasiveness. Marbled crayfish occur in tropical to cold temperate habitats of the old world, but P. fallax is confined to subtropical and warm-temperate habitats of the southeastern USA. Cross-breeding experiments with both crayfish revealed reproductive isolation. The application of the Evolutionary Genetic Species Concept for asexuals to all available data supports raising marbled crayfish from “forma” to species rank. A determination key is provided to discriminate Procambarus virginalis, the first asexual decapod species, from its parent species P. fallax.


2014 ◽  
Vol 27 (6) ◽  
pp. 372 ◽  
Author(s):  
Daniel J. Ohlsen ◽  
Leon R. Perrie ◽  
Lara D. Shepherd ◽  
Michael J. Bayly

Asplenium listeri C.Chr. has been considered endemic to Christmas Island and is one of only two fern species listed as Critically Endangered under Australia’s Environment Protection and Biodiversity Conservation Act. Its status as a distinct species has been questioned because of morphological similarity to the widespread A. polyodon G.Forst., which also occurs on Christmas Island. Molecular analyses revealed that A. listeri and plants attributed to A. polyodon from coastal limestone in New Caledonia and Vanuatu share the same rbcL, trnL–trnF and rps4–trnS haplotype and that other samples of A. polyodon in Australia and the south-western Pacific belong to three separate molecular lineages. One of these lineages is formed by epiphytic A. polyodon from Christmas Island and has a chloroplast haplotype closely related to that of A. listeri, differing by four mutations. The A. listeri haplotype and each of the three A. polyodon lineages are associated with morphological characters and are all worthy of recognition as separate species. Asplenium listeri is here expanded to include limestone dwelling populations in the Pacific previously assigned to A. polyodon. This greatly extends the geographic range of A. listeri, and its conservation status should be revised accordingly. Application of correct names to all species in the A. polyodon complex requires further molecular sampling throughout its geographic range and clarification of how type material relates to each of the molecular groups.


2019 ◽  
Vol 191 (1) ◽  
pp. 142-154 ◽  
Author(s):  
Andrii Tarieiev ◽  
Igor Olshanskyi ◽  
Oliver Gailing ◽  
Konstantin V Krutovsky

Abstract Distribution, taxonomy, nomenclature and molecular genetic data are presented for two closely related pairs of birch taxa: (1) dark-barked Betula pubescens var. sibakademica (Baran.) Kuzeneva (basionym B. sibakademica Baranov) and white-barked B. pubescens var. pubescens, and (2) dark-barked B. kotulae Zaverucha = B. pendula var. obscura (Kotula ex Fiek) Olšavská (basionym B. obscura Kotula ex Fiek, heterotypic synonym B. kotulae) and white-barked B. pendula, respectively. Using published data and sequences obtained in this study, it was found that, although these pairs can be distinguished not only by morphological characters but also by two diagnostic single nucleotide polymorphisms (SNPs) in the internal transcribed spacers ITS1 and ITS2, no sequence differences within each pair were detected. These results suggest that the colour of the bark cannot be used as a taxonomic trait at the species level, and the dark-barked birches within each pair should not be treated as separate species or varieties, but as forms, respectively. Therefore, we reassessed the taxonomic status of B. sibakademica and B. kotulae using morphological traits and molecular genetic markers and suggest that B. pubescens f. sibakademica (Baranov) Tarieiev comb. nov. and B. pendula f. obscura (Kotula ex Fiek) Tarieiev comb. nov. should be used for them, respectively. Betula pubescens f. sibakademica was described in Ukraine for the first time.


Zootaxa ◽  
2018 ◽  
Vol 4455 (1) ◽  
pp. 161 ◽  
Author(s):  
QING ZHAO ◽  
JIUFENG WEI ◽  
WENJUN BU ◽  
GUOQING LIU ◽  
HUFANG ZHANG

Arma custos and A. chinensis have a very conspicuous difference in the shape of the pronotal humeral angle, but the genitalic morphological characters are ambiguous and difficult to recognize. The aim of this study was to analyze the taxonomic status of A. chinensis and A. custos based on morphological, molecular, and geographical evidence, and to determine whether DNA barcoding could be a useful additional tool for differentiating similar species. The results clearly demonstrate that A. custos and A. chinensis have not diverged into separate species. So, the following new synonym is proposed: Arma chinensis Fallou, 1881 = Arma custos (Fabricius, 1794) syn. nov.. The results also showed that DNA barcoding using the marker COI can resolve insect taxonomic problems.


Zootaxa ◽  
2008 ◽  
Vol 1813 (1) ◽  
pp. 51 ◽  
Author(s):  
ALEJO J. IRIGOYEN ◽  
LEOPOLDO CAVALERI GERHARDINGER ◽  
ALFREDO CARVALHO-FILHO

We review the species of Acanthistius Gill (1862) (Osteichthyes, Percoidei) from the South-Western Atlantic, solving a discrepancy concerning the taxonomic status of Acanthistius brasilianus (Cuvier & Valenciennes 1828) and Acanthistius patachonicus (Jenyns 1842), and providing an objective diagnostic key for the two species. While Argentinean fishery biologists consider A. patachonicus to be a synonym of A. brasilianus, ichthyologists elsewhere regard them as separate species with different distributional ranges. Based on a literature review, examination of museum specimens and observation of live individuals in the field, we identified the sources of the dissent and concluded that A. brasilianus and A. patachonicus are separate species, differing in diagnostic morphological characters and distinctive color patterns and having slightly overlapping distributional ranges. Distinction between these two species has significant implications for management and conservation.


Phytotaxa ◽  
2016 ◽  
Vol 268 (1) ◽  
pp. 46 ◽  
Author(s):  
STOYAN S. STOYANOV

Centaurea cyanomorpha, so far known only from a single plant collected in May 1926, was rediscovered and studied at its locus classicus Kara Bair, near the town of Topolovgrad (SE Bulgaria). Its taxonomic status varied in times and remained hitherto uncertain. The species has been treated as a synonym of C. pseudaxillaris, C. napulifera and C. depressa. However, a detailed examination of the type specimen and plants from the type locality, as well as additional plants from different localities indicate that C. cyanomorpha is a clearly distinct taxon and should be maintained as a separate species. Cyanus diospolitanus (≡ Centaurea diospolitana), recently described from Derventski Hills, Yambol Province (SE Bulgaria), has turned out to be identical to C. cyanomorpha and should be treated as a later heterotypic synonym of the latter. Comparisons of the key morphological characters of the close relatives C. cyanomorpha and C. pseudaxillaris and maps of their distributions are given. A new combination, Cyanus cyanomorphus comb. nov., is provided.


2004 ◽  
Vol 35 (3) ◽  
pp. 299-306 ◽  
Author(s):  
◽  
J. M. Tierno de Figueroa ◽  
◽  
◽  

AbstractThe western Mediterranean stonefly genus Tyrrhenoleuctra traditionally includes 3 species: T. minuta (Spain, North Africa, Balearic Islands), T. tangerina (Spain, North Africa), T. zavattarii (Corsica and Sardinia). Since the traditional morphological characters display great and overlapping variation, allozyme electrophoresis was used to clarify taxonomic and phylogenetic relationships within the genus and to discuss biogeographical implications. The results clearly discriminate at least four entities: the Corso-Sardinian unit, for which the name T. zavattarii can be used; the Balearic population, representing an undescribed species; at least two Iberian peninsular species. However, more data on topotypic populations are needed to define the taxonomic status of the Iberian species (including definition of the currently used names T. minuta and T. tangerina). The presence of Tyrrhenoleuctra in Sardinia and Corsica is likely due to an old vicariance event following separation of the Sardinia-Corsica microplate from the Iberian Peninsula. Calibration of the molecular clock (genetic distances vs. Corso-Sardinian plate split from Iberia) resulted in a very low evolutionary rate (0.008 D/my), lower than those found in taxonomically distant groups (including stoneflies) with similar distribution.


2021 ◽  
Vol 32 (2) ◽  
pp. 293-301
Author(s):  
MD JAYEDUL ISLAM ◽  
SHARMIN AKTER ◽  
PROVAKOR SARKAR ◽  
MOHAMMAD RASHED ◽  
IREEN PARVIN ◽  
...  

A new record of Plectropomus pessuliferus (Serranidae: Epinephelinae) wasdocumented based on morphological characters and DNA barcoding. The species was collectedduring a regular survey for making an inventory of reef associated fishes in Saint Martin`sIsland, Bangladesh. This is the first report of roving coral grouper from the marine waters ofBangladesh validated by morpho-meristic analysis and DNA barcoding. This is also the firstreport from the northern Bay of Bengal.


Zootaxa ◽  
2021 ◽  
Vol 5068 (2) ◽  
pp. 211-239
Author(s):  
CLAUDIA LANSAC ◽  
RODRIGO AGUAYO ◽  
IGNACIO DE LA RIVA

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.  


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