scholarly journals Application of the geometric morphometrics approach in the discrimination of morphological traits between brown trout lineages in the Danube Basin of Croatia

Author(s):  
Ivan Špelić ◽  
Andrea Rezić ◽  
Tamara Kanjuh ◽  
Ana Marić ◽  
Ivana Maguire ◽  
...  

Brown trout is a salmonid fish with a natural range extending throughout western Eurasia and North Africa. Due to its commercial value, it has also been introduced worldwide. In continental Croatia, introduced trout of the Atlantic lineage hybridizes with native trout of the Danubian lineage, threatening the native genetic diversity. The geometric morphometrics approach was used in this study to analyse changes in shape between native trout, introduced trout and their hybrids, classified a priori by molecular phylogenetic analyses. A total of 19 landmarks and semi-landmarks were used to capture the shape of 92 trout individuals belonging to two lineages and their hybrids. Canonical variate analysis and discriminant function analysis were used to analyse and describe shape variation. A significant difference was found between the shape of the Atlantic lineage trout and both Danubian lineage trout and hybrids, with the most prominent differences in body depth, head length and eye size. No statistically significant shape differences were observed between Danubian lineage trout and the hybrids. The observed significant differences in shape could be the result of genetic diversity or trout phenotypic plasticity. Further studies are needed to clarify the origin of this variation in shape.

2019 ◽  
Vol 35 (6) ◽  
Author(s):  
Daniel Vieira de Morais ◽  
Lorena Andrade Nunes ◽  
Vandira Pereira da Mata ◽  
Maria Angélica Pereira de Carvalho Costa ◽  
Geni da Silva Sodré ◽  
...  

Leaves are plant structures that express important traits of the environment where they live. Leaf description has allowed identification of plant species as well as investigation of abiotic factors effects on their development, such as gases, light, temperature, and herbivory. This study described populations of Dalbergia ecastaphyllum through leaf geometric morphometrics in Brazil. We evaluated 200 leaves from four populations. The principal component analysis (PCA) showed that the first four principal components were responsible for 97.81% of variation. The non-parametric multivariate analysis of variance (NPMANOVA) indicated significant difference between samples (p = 0.0001). The Mentel test showed no correlation between geographical distances and shape. The canonical variate analysis (CVA) indicated that the first two variables were responsible for 96.77 % of total variation, while the cross-validation test showed an average of 83.33%. D. ecastaphyllum leaves are elliptical and ovate.


2016 ◽  
Vol 4 (16) ◽  
pp. 1
Author(s):  
Mariya A. Chursina ◽  
Oleg P. Negrobov

A study of 186 specimens of Poecilobothrus regalis was conducted in order to examine intraspecific variability of wing shape. The wing shape variation was analyzed using geometric morphometrics analyses. Significant differences in the structure of wing were found both between sexes and between populations. Differences between sexes were observed in the structure of the medium portion of wing. The first extracted canonical variate of geographic variation showed a moderately linear association with latitude and average temperature of February and March. The second canonical variate was correlated with longitude and values of average wind flow velocity. Allometric relationships were weak both between populations and sexes.


2018 ◽  
Vol 32 (6) ◽  
pp. 1448
Author(s):  
Tamara Karan-Žnidaršič ◽  
Vukica Vujić ◽  
Ángel Baltanás

Natural selection can lead to speciation, but its effects depend on amount of morphological variation within populations. In Ostracoda, the appendages enclosed within the calcified carapace are less influenced by environmental conditions in comparison with carapace valves. Here, we explored morphological variation of appendages and labrum in cosmopolitan genus Heterocypris, investigating the species occurring in Europe. With the aim to overcome taxonomical problems, both traditional and geometric morphometrics were applied. The relative lengths were analysed by one-way ANOVA and post-hoc tests to determine interspecific variation and sexual dimorphism. Significant traits were further analysed by Canonical Variate Analysis separately for males and females as segment width/length ratios and relative length of claws and setae ratios. Landmark-based geometric morphometrics were applied to analyse shape variation of the labrum and traits of the maxillular palp. From this, a new perspective on morphological variation within this genus emerged. Relative measurements of the second segment of the maxillular palp, and relative lengths of the natatory setae were found to be the characters that contribute most to discrimination among Heterocypris species. The most important discriminant traits in females are the relative lengths of the G2 and G1 claws. Heterocypris exigua is additionally described, as all findings demonstrated that this is the most distinctive species, the most similar to H. gevgelica. In conclusion, we found that in comparison with maxillular palp and other analysed characters, labrum traits showed as more reliable and deserve more attention in descriptions of new species.


2021 ◽  
Vol 22 (10) ◽  
Author(s):  
Jennifer Danila ◽  
GRECEBIO JONATHAN D. ALEJANDRO

Abstract. Danila JS, Alejandro GJD. 2021. Leaf geometric morphometric analyses of Callicarpa and Geunsia (Lamiaceae) in the Malesian region. Biodiversitas 22: 4379-4390. Leaves are one of the most substantial organs of plants for it serves as a basis of species identification. Leaf morphology provides distinguishing features that help in the discrimination of plant species as well as investigation of leaf features among populations. This study aimed to investigate leaf shape variations between the two genera Geunsia Blume group and its closely related taxon, Callicarpa L. (Lamiaceae) using a landmark-based geometric morphometric method. The differences in the leaf shape among former members of Geunsia, namely C. apoensis, C. basilanensis, C. flavida, C. paloensis, C. pentandra, C. ramiflora, and C. surigaensis are also evaluated. Two primary landmarks and 14 semilandmarks were assigned in all samples to represent changes around the leaf margin. The Procrustes fit was generated using MorphoJ software which displays the mean and landmark position for individual configurations. Canonical Variate Analysis (CVA) and Mahalanobis Distance (MD) were able to discriminate all samples of Geunsia species using a scatter plot. Furthermore, Procrustes ANOVA showed a significant difference (P = 0.0082) among the seven species of the Geunsia group. Based on the results obtained, geometric morphometrics of leaf shape is effective in interspecific discrimination within members of Geunsia. However, the result of Discriminant Analysis (DA) showed that Geunsia and Callicarpa groups made leaf shape differences inefficient in discriminating the two genera. Therefore, further morphological studies on landmark-based geometric morphometrics of leaf shape involving a larger number of samples especially in the study of intergeneric classification are suggested.


2010 ◽  
Vol 365 (1547) ◽  
pp. 1763-1782 ◽  
Author(s):  
Kathryn R. Elmer ◽  
Henrik Kusche ◽  
Topi K. Lehtonen ◽  
Axel Meyer

The polychromatic and trophically polymorphic Midas cichlid fish species complex ( Amphilophus cf. citrinellus ) is an excellent model system for studying the mechanisms of speciation and patterns of phenotypic diversification in allopatry and in sympatry. Here, we first review research to date on the species complex and the geological history of its habitat. We analyse body shape variation from all currently described species in the complex, sampled from six crater lakes (maximally 1.2–23.9 kyr old) and both great lakes in Nicaragua. We find that Midas cichlid populations in each lake have their own characteristic body shape. In lakes with multiple sympatric species of Midas cichlid, each species has a distinct body shape. Across the species complex, most body shape change relates to body depth, head, snout and mouth shape and caudal peduncle length. There is independent parallel evolution of an elongate limnetic species in at least two crater lakes. Mitochondrial genetic diversity is higher in crater lakes with multiple species. Midas cichlid species richness increases with the size and age of the crater lakes, though no such relationship exists for the other syntopic fishes. We suggest that crater lake Midas cichlids follow the predicted pattern of an adaptive radiation, with early divergence of each crater lake colonization, followed by intralacustrine diversification and speciation by ecological adaptation and sexual selection.


Biologia ◽  
2013 ◽  
Vol 68 (6) ◽  
Author(s):  
Jan Kohout ◽  
Alena Šedivá ◽  
Apostolos Apostolou ◽  
Tihomir Stefanov ◽  
Saša Marić ◽  
...  

AbstractThe study focuses on the phylogenetic origin and genetic diversity of brown trout in the eastern part of the Balkan Peninsula. It further aims to reveal the impact of human-mediated transfers and stocking with non-indigenous trout on the populations in this area. For these purposes, mtDNA control region and microsatellite variation of 204 individuals from 16 populations were analysed. The results indicate that mtDNA haplotypes from the lower Danube basin and southern Black Sea basins differ substantially from a subclade of the Danubian lineage consisting of haplotypes found so far in the most of the Danube basin and in the Caspian and Aral Sea basins. Considering also the results of demographic analyses, this study evidences a complex evolutionary history of brown trout in the southern and western parts of the Black Sea basin. In the Aegean Sea basin, a high frequency of the central haplotype of Adriatic mtDNA lineage has been found. The other Adriatic lineage haplotypes found in this basin differ from the central haplotype by one mutational step only, indicating a recent evolution of the Adriatic lineage in the Aegean Sea basin. Substantial genetic differentiation among populations and basins was revealed. The hybridization with Atlantic brown trout was indicated in both sea basins, but especially in the Danube basin. Compared to other European regions, it can be inferred that the introgression of exogenous brown trout in the eastern Balkan populations is rather low.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4242 ◽  
Author(s):  
Julian Katzke ◽  
Phillip Barden ◽  
Manuel Dehon ◽  
Denis Michez ◽  
Torsten Wappler

Shape is a natural phenomenon inherent to many different lifeforms. A modern technique to analyse shape is geometric morphometrics (GM), which offers a whole range of methods concerning the pure shape of an object. The results from these methods have provided new insights into biological problems and have become especially useful in the fields of entomology and palaeontology. Despite the conspicuous successes in other hymenopteran groups, GM analysis of wings and fossil wings of Formicidae has been neglected. Here we tested if landmarks defining the wing shape of fossil ants that belong to the genusTitanomyrmaare reliable and if this technique is able to expose relationships among different groups of the largest Hymenoptera that ever lived. This study comprises 402 wings from 362 ants that were analysed and assigned with the GM methods linear discriminant function analysis, principal component analysis, canonical variate analysis, and regression. The giant ant genusTitanomyrmaand the parataxonFormiciumhave different representatives that are all very similar but these modern methods were able to distinguish giant ant types even to the level of the sex. Thirty-five giant ant specimens from the Eckfeld Maar were significantly differentiable from a collection of Messel specimens that consisted of 187Titanomyrma giganteafemales and 42T. giganteamales, and from 74Titanomyrma simillimafemales and 21T. simillimamales. Out of the 324 Messel ants, 127 are newly assigned to a species and 223 giant ants are newly assigned to sex with GM analysis. All specimens from Messel fit to the two species. Moreover, shape affinities of these groups and the speciesFormicium brodiei,Formicium mirabile, andFormicium berryi, which are known only from wings, were investigated.T. giganteastands out with a possible female relative in one of the Eckfeld specimens whereas the other groups show similar shape patterns that are possibly plesiomorphic. Formicidae are one of the most dominant taxa in the animal kingdom and new methods can aid in investigating their diversity in the present and in deep time. GM of the ant wing delivers significant results and this core of methods is able to enhance the toolset we have now to analyse the complex biology of the ants. It can prove as especially useful in the future when incorporated into better understanding aspects of evolutionary patterns and ant palaeontology.


PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0260333
Author(s):  
Danita Champakaew ◽  
Anuluck Junkum ◽  
Narin Sontigun ◽  
Sangob Sanit ◽  
Kwankamol Limsopatham ◽  
...  

Mosquitoes are hematophagous insects that transmit parasites and pathogens with devastating effects on humans, particularly in subtropical regions. Different mosquito species display various behaviors, breeding sites, and geographic distribution; however, they can be difficult to distinguish in the field due to morphological similarities between species and damage caused during trapping and transportation. Vector control methods for controlling mosquito-borne disease epidemics require an understanding of which vector species are present in the area as well as the epidemiological patterns of disease transmission. Although molecular techniques can accurately distinguish between mosquito species, they are costly and laborious, making them unsuitable for extensive use in the field. Thus, alternative techniques are required. Geometric morphometrics (GM) is a rapid and inexpensive technique that can be used to analyze the size, shape, and shape variation of individuals based on a range of traits. Here, we used GM to analyze the wings of 1,040 female mosquitoes from 12 different species in Thailand. The right wing of each specimen was removed, imaged microscopically, and digitized using 17 landmarks. Wing shape variation among genera and species was analyzed using canonical variate analysis (CVA), while discriminant function analysis was used to cross-validate classification reliability based on Mahalanobis distances. Phenetic relationships were constructed to illustrate the discrimination patterns for genera and species. CVA of the morphological variation among Aedes, Anopheles, Armigeres, Culex, and Mansonia mosquito genera revealed five clusters. In particular, we demonstrated a high percentage of correctly-distinguished samples among Aedes (97.48%), Armigeres (96.15%), Culex (90.07%), and Mansonia (91.67%), but not Anopheles (64.54%). Together, these findings suggest that wing landmark-based GM analysis is an efficient method for identifying mosquito species, particularly among the Aedes, Armigeres, Culex, and Mansonia genera.


2020 ◽  
Vol 20 (2) ◽  
pp. 189
Author(s):  
Muhammad Nur ◽  
M.Fadjar Rahardjo ◽  
Charles P.H. Simanjuntak ◽  
Djumanto Djumanto ◽  
Krismono Krismono

Pirik (Lagusia micracanthus Bleeker, 1860) is one of endemic fishes in Sulawesi. Morphometric and meristic information of Pirik population in various habitats are unknown. The present study aimed to determine the morphometric and meristic variation of Pirik in Maros and Wallanae Cenrana watersheds. Sampling collection was carried out monthly from May 2018 to April 2019 in the Maros watershed, namely Pattunuang River (M1), Bantimurung River (M2), Pucak River (M3); and in Wallanae Cenrana watershed particularly in Camba River (W1), Sanrego River (W2), and Ompo River (W3). Morphometric measurements consisted of 31 characters and meristic measurements consisted of 10 characters. Morphometric data was standardized by dividing all morphometric characters by standard length (SL). Analysis of variance (ANOVA) and discriminant analysis (Discriminant Function Analysis) were applied for data analysis. The results showed that the Pirik taken from rivers in the Maros and Wallanae Cenrana watershed are two different population groups. There are 12 distinguishing morphometric features for Pirik of the Maros and Wallanae Cenrana watershed, i.e. TL (total length), SL (standard length), BDdSA (body depth-dorsal fin origin), HL (head length), Jlup (upper-jaw length), PAfL (pre-anal fin length), ABL (Anal fin base length), PelRL (pelvic ray length), AFRL (anal fin ray length), CPL (caudal peduncle length), CLLup (upper caudal lobe length) and CLLmid (mid-caudal length). There is no significant difference of meristic characters of Pirik obtained from the Maros and Wallanae Cenraa watersheds.


2020 ◽  
Vol 18 (3) ◽  
pp. 210-218
Author(s):  
Guolong Yu ◽  
Yan Li ◽  
Xuhe Huang ◽  
Pingping Zhou ◽  
Jin Yan ◽  
...  

Background: HIV-1 CRF55_01B was first reported in 2013. At present, no report is available regarding this new clade’s polymorphisms in its functionally critical regions protease and reverse transcriptase. Objective: To identify the diversity difference in protease and reverse transcriptase between CRF55_01B and its parental clades CRF01_AE and subtype B; and to investigate CRF55_01B’s drug resistance mutations associated with the protease inhibition and reverse transcriptase inhibition. Methods: HIV-1 RNA was extracted from plasma derived from a MSM population. The reverse transcription and nested PCR amplification were performed following our in-house PCR procedure. Genotyping and drug resistant-associated mutations and polymorphisms were identified based on polygenetic analyses and the usage of the HIV Drug Resistance Database, respectively. Results: A total of 9.24 % of the identified CRF55_01B sequences bear the primary drug resistance. CRF55_01B contains polymorphisms I13I/V, G16E and E35D that differ from those in CRF01_AE. Among the 11 polymorphisms in the RT region, seven were statistically different from CRF01_AE’s. Another three polymorphisms, R211K (98.3%), F214L (98.3%), and V245A/E (98.3 %.), were identified in the RT region and they all were statistically different with that of the subtype B. The V179E/D mutation, responsible for 100% potential low-level drug resistance, was found in all CRF55_01B sequences. Lastly, the phylogenetic analyses demonstrated 18 distinct clusters that account for 35% of the samples. Conclusions: CRF55_01B’s pol has different genetic diversity comparing to its counterpart in CRF55_01B’s parental clades. CRF55_01B has a high primary drug resistance presence and the V179E/D mutation may confer more vulnerability to drug resistance.


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