scholarly journals Chrysomya megacephala (Fabricius, 1794) (Diptera: Calliphoridae) development by landmark-based geometric morphometrics of cephalopharyngeal skeleton: a preliminary assessment for forensic entomology application

Author(s):  
Li-Xuan Sim ◽  
Raja M. Zuha

Abstract Background Considering the practicality of geometric morphometrics which could discriminate insect species, this application was extended to the analysis of blow fly larval growth based on cephalopharyngeal skeleton. In forensic entomology, cephalopharyngeal skeleton plays a crucial role in species identification but the morphometric information of this part is scarce. In this study, Chrysomya megacephala (Fabricius, 1794) was reared in two study replicates in natural conditions and samplings were conducted at fixed daily intervals. Cephalopharyngeal skeletons were removed from larvae and mounted on glass slides. Images were obtained from the specimens; digitized and geometric morphometric analysis on C. megacephala cephalopharyngeal skeletons was performed with MorphoJ software based on the ordination of five landmarks. The assessments of this analysis were based on centroid size measurements, visualization on the landmarks displacements, classification of the relative landmarks by using canonical variate analysis, and ontogenetic allometry determination. Findings Centroid size was strongly correlated with developmental time (p < 0.05) and significantly different between daily intervals (p < 0.05). Ontogenetic allometric effect based on multivariate regression on Procrustes coordinates and centroid size was significant (p < 0.0001), indicating that shape was influenced by growth (60.3%). Disposition occurred on all landmarks during development and was further discriminated based on age groups. Conclusions Other than discriminating between species, geometric morphometrics was found to be practical to visualize larval growth based on cephalopharyngeal skeletons which can be useful in forensic entomology.

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.


Insects ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 341
Author(s):  
Jean-Philippe Martinet ◽  
Hubert Ferté ◽  
Pacôme Sientzoff ◽  
Eva Krupa ◽  
Bruno Mathieu ◽  
...  

Background: In the context of the increasing circulation of arboviruses, a simple, fast and reliable identification method for mosquitoes is needed. Geometric morphometrics have proven useful for mosquito classification and have been used around the world on known vectors such as Aedes albopictus. Morphometrics applied on French indigenous mosquitoes would prove useful in the case of autochthonous outbreaks of arboviral diseases. Methods: We applied geometric morphometric analysis on six indigenous and invasive species of the Aedes genus in order to evaluate its efficiency for mosquito classification. Results: Six species of Aedes mosquitoes (Ae. albopictus, Ae. cantans, Ae. cinereus, Ae. sticticus, Ae. japonicus and Ae. rusticus) were successfully differentiated with Canonical Variate Analysis of the Procrustes dataset of superimposed coordinates of 18 wing landmarks. Conclusions: Geometric morphometrics are effective tools for the rapid, inexpensive and reliable classification of at least six species of the Aedes genus in France.


2017 ◽  
Vol 10 (1) ◽  
pp. 09-13 ◽  
Author(s):  
Marcos Patrício Macedo

Resumo.Chrysomya albiceps (Weidemann), Chrysomya megacephala (Fabricius) e Hemilucilia segmentaria (Fabricius)(Diptera, Calliphoridae) estão entre as espécies de dípteros necrófagos mais encontrados em locais de crime no Brasil. A correta identificação do espécime, ou fragmento deste, coletado em um local de crime é etapa fundamental para o emprego da entomologia forense em investigações criminais. Nesse estudo, avaliamos a possibilidade de identificação dessas três espécies de califorídeos pela morfologia alar, por meio de análises de morfometria geométrica. Foram analisadas as asas direitas de 139 espécimes, 55 C. albiceps, 42 C. megacephala e 42 H. segmentaria, por meio de análises de variáveis canônicas e análises discriminantes. Das 278 comparações par a par, apenas 6 seis erros de identificação foram registrados (2,1%), enquanto 22 (7,9%) erros de classificação para o teste de validação cruzada, o que aponta para um alto índice de confiabilidade da técnica. Mais estudos são necessários para a validação dessa técnica para seu uso na prática forense..Wing geometric morphometry as a tool for the identification of three calliphorid (Diptera: Calliphoridae) species at the Brazilian CerradoAbstract. Chrysomya albiceps (Weidemann), Chrysomya megacephala (Fabricius) and Hemilucilia segmentaria (Fabricius) (Diptera: Calliphoridae) are among the fly species of forensic interest commonly found in Brazil. The correct identification of the specimen, or fragment of a specimen, collected at a crime scene is a crucial step for the use of forensic entomology as a tool in criminal investigations. In this study, the discrimination of these three species of Calliphoridae based on wing morphology, by means of geometric morphometric analysis was investigated. Right wings of 139 specimens were analyzed, 55 C. albiceps, 42 C. megacephala e 42 H. segmentaria, through Canonical Variate Analysis, Discriminant Analysis and Cross Validation tests. Of the 278 pairwise comparison, six misidentifications were recorded for discriminant analysis (2.1%), while 22 (7.9 %) misclassification for cross-validation tests, which points to a high technical reliability index. More studies are needed to validate this technique for use in forensic practice.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Yi Feng Wen ◽  
Hai Ming Wong ◽  
Tao Pei ◽  
Colman McGrath

AbstractThis study aimed to investigate changes in types of dental arch form during adolescence and explore adolescent changes in size and form of dental arch. Hong Kong Chinese were recruited and digital dental arch models were obtained at ages 12, 15, and 18 years. Geometric morphometrics was used to investigate adolescent changes of dental arch form. There were 225 participants from whom digital models at all three age periods were available. Three types of dental arch form were identified through clustering. Significant changes (p < 0.001) in types of dental arch form were noted during age 12–18 years. During age 12–18 years, significant changes in centroid size and form of dental arch were observed (p < 0.001). No significant changes were observed during 15–18 years. Adolescent changes of dental arch form occur primarily during age 12–15 years, whereas dental arch form was relatively stable during age 15–18 years.


2015 ◽  
Vol 67 (3) ◽  
pp. 929-934 ◽  
Author(s):  
Sladjan Rasic ◽  
Mica Mladenovic ◽  
Ljubisa Stanisavljevic

In a selection of honeybees from autochthonous ecotypes, different lines must be identified. Honeybee lineages are usually distinguished by classical morphometrics and molecular markers, but these approaches are both costly and time-consuming to implement. Recognition of the purity of races is very important for regional and country regulations to allow a sustainable conservation of the huge variety of local honeybees. A geometric morphometric approach has been frequently used. In this work, honeybee samples were collected from stationary apiaries (belonging to the centers for honeybee queen selection) from two different Serbian areas: Vrsac (northeastern Serbia, mostly flatland) and Vranje (southern Serbia, mostly mountainous), and two different Montenegrin areas: Bijelo Polje (northern Montenegro, mountainous region) and Sutomore (southern Montenegro, coastal region). Each sample consisted of 150 honeybee workers, collected from 10 hives (15 specimens each). On the honeybee left forewings, a total of 19 vein intersections were used to determine the differences among the honeybees using MorphoJ 1.4a software. Canonical variate analysis (CVA) slightly separated the honeybee lines into one overlapping cloud of specimens at the individual level. The first canonical variable (60.57% of the total variability) discriminated mainly between Bijelo Polje and Sutomore honeybee lines. Therefore, on the colony level, CVA separated all four groups of breeding honeybee lines. The results show that geometric morphometrics are reliable in the discrimination of honeybee lines within subspecies only at the colony level.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Renan Rodrigues Rocha ◽  
Rosana de Mesquita Alves ◽  
Rubens Pasa ◽  
Karine Frehner Kavalco

The Astyanax scabripinnis complex is composed of a large number of almost morphological indistinguishable species, including Astyanax paranae and Astyanax rivularis, which exist in the Paraná and São Francisco Basins, respectively, and sometimes are considered subspecies of the A. scabripinnis group or even are cited just as A. scabripinnis. The two river basins are separated by the Upper Paranaíba Arc, likely the main cause of the isolation of these species. We used geometric morphometric tools and DNA analyses of populations of both species to identify the differences between them. Geometric morphometrics separated the two species into distinct groups, whose main difference was the body depth. This is generally related to the speed of the water flow in the river basins. The maximum likelihood phylogram based on mitochondrial DNA sequences formed two main clades: one composed of the population of A. rivularis and the other, of A. paranae. In the haplotype network, the species were similarly separated into two groups from the same ancestral haplotype, with A. rivularis dispersing into two lineages in the São Francisco River Basin. The distribution of A. paranae is a consequence of a secondary dispersion event in the Paraná River Basin. It forms two lineages from a haplotype derived from the ancestor. The vicariant effect of separate basins, through the elevation of the Upper Paranaíba Arc, led to the allopatric speciation of the populations originating the present species. The results of geometric morphometrics and molecular data of the fish show the importance of this geological event in the biogeography and evolutionary history of the ichthyofauna of the region and indicate that the isolation of these species seems to be effective.


Author(s):  
Valentina P. Vetrova ◽  
◽  
Alexey P. Barchenkov ◽  
Nadezhda V. Sinelnikova ◽  
◽  
...  

Geometric morphometric analysis of shape variation in the cone scales of two closely related larch species, Larix dahurica Laws. (=Larix gmelinii (Rupr.) Rupr) and L. cajanderi Mayr, was carried out. The data on the taxonomy and distribution of L. dahurica and L. cajanderi are contradictory. The taxonomic status of L. cajanderi has been confirmed by the genetic and morphological studies performed in Russia and based on considerable evidence, but the species has not been recognized internationally, being considered as a synonym of Larix gmelinii var. gmelinii. In the systematics of larch, morphological characters of the generative organs are mainly used as diagnostic markers, among the most important being the shape variation of the cone scales. The aim of this study was to test geometric morphometrics as a tool for analyzing differentiation of L. dahurica and L. cajanderi in the shape of their cone scales. Characterization of shape variations in cone scales using geometric morphometric methods consists in digitizing points along an outline of scales followed by analysis of partial warps, describing individual differences in coordinates of the outline points. We studied the populations of L. dahurica from Evenkia and the Trans-Baikal region and six L. cajanderi populations from Yakutia and Magadan Oblast. In each population, we analyzed samples of 100-150 cones collected from 20-30 trees. Scales taken from the middle part of the cones were scanned using an Epson Perfection V500 Photo. On the scanned images, outline points were placed with a TPSDig program (Rolf, 2010), using angular algorithm (Oreshkova et al., 2015). The data were processed and analyzed using Integrated Morphometrics Programs (IMP) software (http://www.canisius.edu/~sheets/ morphsoft.html, Sheets, 2001), following the guidelines on geometric morphometrics in biology (Pavlinov, Mikeshina, 2002; Zelditch et al., 2004). Initial coordinates of the scale landmarks were aligned with the mean structure for L. dahurica and L. cajanderi cone scales using Procrustes superimposition in the CoordGen6 program. PCA based on covariances of partial warp scores was applied to reveal directions of variation in the shape of the cone scales. The relative deformations of the cone scales (PCA scores) were used as shape variables for statistical comparisons of these two larch species with canonical discriminant analysis. Morphotypes of the cone scales were distinguished in L. dahurica populations by pairwise comparison of samples from trees in the TwoGroup6h program using Bootstrap resampling-based Goodall’s F-test (Sheets, 2001). Samples from the trees in which the cone scales differed significantly (p < 0.01) were considered to belong to different morphotypes. Morphotypes distinguished in L. dahurica populations were compared with the morphotypes that we had previously determined in L. cajanderi populations. The composition and the frequency of occurrence of morphotypes were used to determine phenotypic distances between populations (Zhivotovskii, 1991). Multidimensional scaling matrix of the phenotypic distances was applied for ordination of larch populations. In this research, we revealed differentiation of L. dahurica and L. cajanderi using geometric morphometric analysis of the shape variation of cone scales. The results of PCA of partial warp scores exposed four principal components, which account for 90% of total explained variance in the shape of the cone scales in the two larch species. Graphical representations of these shape transformations in the vector form characterized directions of shape variability in scales corresponding to the maximum and minimum values of four principal components (See Fig. 2). PCA-ordination of the larch populations revealed some difference in the shape variation of the cone scales in L. dahurica and L. cajanderi (See Fig. 3). The results of canonical discriminant analysis of relative deformations of scales showed differentiation of the populations of the two larch species (See Fig. 4). Eleven morphotypes were identified in L. dahurica cones from Evenkia and nine morphotypes in the Ingoda population, three of the morphotypes being common for both populations (See Fig. 5). The shape of L. dahurica cone scales varied from spatulate to oval and their apical margins from weakly sinuate to distinctly sinuate. The Trans-Baikal population was dominated by scales with obtuse (truncate) and rounded apexes. The obtained morphotypes were compared with 25 cone scale morphotypes previously distinguished in the Yakut and the Magadan L. cajanderi populations (See Fig. 3). Four similar morphotypes of cone scales were revealed in the North-Yeniseisk population of L. dahurica and the Yakut populations of L. cajanderi. The differences between them in the populations of the two larch species were nonsignificant (p > 0.01). All morphotypes of cone scales from the Ingoda population of L. dahurica differed significantly from L. cajanderi cone scale morphotypes. The results of multidimensional scaling phenotypic distance matrix calculated based on the similarity of morphotypes of L. dahurica and L. cajanderi populations were consistent with the results of their differentiation based on relative deformations of scales obtained using canonical discriminant analysis (See Fig. 4 and Fig. 7). In spite of the differences in the shape of the cone scales between the North-Yeniseisk and the Trans-Baikal populations of L. dahurica, they both differed from L. cajanderi populations. Thus, phenotypic analysis confirmed differentiation of these two larch species. Despite the similarities between a number of morphotypes, the Yakut L. cajanderi populations were differentiated from L. dahurica populations. Significant differences were noted between intraspecific groups: between L. cajanderi populations from Okhotsk-Kolyma Upland and Yakutia and between L. dahurica populations from Evenkia and the Trans-Baikal region (See Fig. 4). The similarities between species and intraspecific differences may be attributed to the ongoing processes of hybridization and species formation in the region where the ranges of the larches overlap with the ranges of L. czekanowskii Szafer and L. dahurica×L. cajanderi hybrids. Geometric morphometrics can be used as an effective tool for analyzing differentiation of L. dahurica and L. cajanderi in the shape of their cone scales.


2021 ◽  
Vol 11 (17) ◽  
pp. 7848
Author(s):  
Darío Herranz-Rodrigo ◽  
Silvia J. Tardáguila-Giacomozzi ◽  
Lloyd A. Courtenay ◽  
Juan-José Rodríguez-Alba ◽  
Antonio Garrucho ◽  
...  

Recent studies using geometric morphometrics for taphonomy have yielded interesting results, opening new horizons of research in both archaeological and paleontological sites. Here we present the analysis of tooth pits left by male and female individuals of two different carnivore species (Panthera tigris and Panthera pardus) in order to see if sexual dimorphism influences the morphology of tooth pit marks. In the process, 3D-scanning and applied statistics were used. Based on samples derived from two individuals of different sexes, the present results indicate sexual dimorphism in these felid species to not be a conditioning factor of tooth pit morphology.


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.


2009 ◽  
Vol 100 (1) ◽  
pp. 19-26 ◽  
Author(s):  
M.L. Lyra ◽  
L.M. Hatadani ◽  
A.M.L. de Azeredo-Espin ◽  
L.B. Klaczko

AbstractCochliomyia hominivoraxandCochliomyia macellariaare endemic Neotropical Calliphoridae species. The former causes severe myiasis in hosts while the latter is Sarcosaprophagous, but commonly found as a second invader in wounds. Due to the morphological similarity between them and the potential losses thatC. hominivoraxrepresents for cattle breeders, the rapid and correct identification of these two species is very important. In addition to a correct identification of these species, a good knowledge ofC. hominivoraxbiology can be helpful for designing control programs. We applied geometric morphometric methods to assess wing differences betweenC. hominivoraxandC. macellariaand conduct a preliminary analysis of wing morphological variation inC. hominivoraxpopulations. Canonical variate analysis, using wing shape data, correctly classified 100% of the individuals analyzed according to sex and species. This result demonstrates that wing morphometry is a simple and reliable method for identifyingC. hominivoraxandC. macellariasamples and can be used to monitorC. hominivorax. Both species show sexual dimorphism, but inC. hominivoraxit is magnified. We suggest that this may reflect different histories of selection pressures operating on males and females. Significant differences in wing size and shape were obtained amongC. hominivoraxpopulations, with little correlation with latitude. This result suggests that wing variation is also a good morphological marker for studying population variation inC. hominivorax.


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