Canonical Variate Analysis Research Articles

Analysis of the pharyngeal structure of the genus Oreochromis for species identification through geometric morphometrics in the Aguamilpa reservoir, Nayarit, Mexico

Tilapia is an important fishing resource in economic terms for continental ecosystems such as dam reservoirs and lagoons. In Nayarit, the Aguamilpa Dam reservoir contributes around 50 % of the tilapia production in the state. However, despite the social and economic importance of the resource, there are few studies on it in this reservoir, and it is still unknown with certainty which species are found in the reservoir. This work is the first report for the Aguamilpa reservoir, where geometric morphometrics was used as a tool for the identification of tilapia species. The pharyngeal plate of 230 organisms was used for the geometric morphometrics analysis. According to this study, the existence of three species of the genus Oreochromis (O. aureus, O. niloticus and Oreochromis mossambicus) is confirmed; according to the analysis of canonical variables, the three species were correctly discriminated. This allows us to conclude that the use of geometric morphometrics in the pharyngeal plate is a useful structure for the identification of species in the reservoir.

Molar enamel–dentine junction shape of Pliobates cataloniae and other Iberian pliopithecoids

The phylogenetic relationships of the small-bodied catarrhine Pliobates cataloniae (∼11.6 Ma, NE Iberian Peninsula) have been controversial since its original description. However, the recent report of additional dentognathic remains has supported its crouzeliid pliopithecoid status. Based on the available hypodigm, the molar enamel–dentine junction (EDJ) shape of P. cataloniae is compared with that of other pliopithecoids from the same basin as well as both extinct and extant hominoids to further evaluate its pliopithecoid affinities. We also quantitatively compare the EDJ shape among these taxa by means of landmark-based three-dimensional geometric morphometrics using principal component analysis (PCA), canonical variate analysis, and between-group PCA. Permutation tests are performed to test whether Pliobates variation exceeds that of extant hominoid genera. Results indicate that Pliobates is similar in molar EDJ shape to other pliopithecoids, particularly crouzeliids. The variation displayed by Pliobates upper molars is less marked at the EDJ level than at the outer enamel surface, probably owing to differential enamel wear and intraspecific differences in enamel thickness. Multivariate analyses of EDJ shape show that all pliopithecoids (including Pliobates) cluster together in the PCAs, canonical variate analyses, and between-group PCAs and occupy a different portion of the morphospaces from extinct and extant hominoids. Posterior and typicality probabilities strongly support the classification of Pliobates as a pliopithecoid, wheras permutation tests fail to reject the single-genus hypothesis for the P. cataloniae hypodigm. We conclude that P. cataloniae is a crouzeliid pliopithecoid, as recently supported by cladistic analyses of craniodental characters, and that previous cladistic results that supported a stem hominoid status are attributable to postcranial convergences with crown hominoids. Our results further highlight the potential of three-dimensional geometric morphometrics analyses of the EDJ shape for better informing fossil primate alpha-taxonomy by means of quantitatively testing hypotheses about tooth shape variation.

Investigation of the shape of goat (capra hircus) astragalus via geometric morphometry method

The aim of this study is to determine the effect of sex on shape of goat astragalus via geometric morphometry method. A total of 37 astragalus bone samples collected from 16 female and 21 male goats were used as material. Bone samples were cleaned from skin and soft tissue and then macerated by boiling. Astragalus bone samples were photographed from a distance of 20 cm dorsally by focusing on the center of the bone. The photographs were transferred to the computer in JPEG format. Principal Component Analysis, Regression Analysis, Canonical Variate Analysis, and Discriminant Function Analysis were conducted using the Cartesian coordinate values, which were obtained by homologous landmark marking. The first two principal components accounted for 75.967% of the total shape variation. Shape variation was determined in different regions of the astragalus. According to the scatter plot of male and female individuals, male individuals were completely placed within the confidence interval ellipse of female individuals. It was found that allometric effect on the shape of astragalus bone was not statistically significant. As a result of Canonical Variate Analysis, mahalanobis and procrustes distances were detected as 2.9216 (p

A novel global modelling strategy integrated dynamic kernel canonical variate analysis for the air handling unit fault detection via considering the two-directional dynamics

As an indispensable component of air-conditioning system, the air handling unit (AHU) always exhibits strong nonlinearity and two-directional dynamics (time-wise and batch-wise dynamics). However, existing monitoring strategies cannot adequately figure out the AHU's two-directional dynamics from the nonlinear data. To boost the AHU's fault detection performance, a novel global modelling scheme integrated dynamic kernel canonical variate analysis (GDKCVA) is developed in this paper. The first contribution is to collect datasets from various days to develop a three-way training dataset and then normalize it along the batch-wise to suppress the batch-wise dynamics and variables' correlations. The second contribution is to establish the dynamic kernel CVA by integrating autoregressive moving average exogenous framework to more effectively confront the time-wise dynamics and variables' nonlinear relationships. The kernel matrices of augmented batch dataset are determined utilizing the kernel trick that transforms nonlinear data into high-dimensional linear space by leveraging kernel function. The third contribution is to propose a novel global modelling strategy to further eliminate the batch-wise dynamics by computing the total average kernel matrices from all the normal batch datasets. Finally, experiments and comparisons on the ASHRAE RP-1312 datasets are carried out to assess the suggested GDKCVA's fault detection capability. Compared with the kernel CVA (KCVA), the three-way training dataset based CVA (TCVA) and the three-way training dataset based KCVA (TKCVA), the proposed GDKCVA has the highest fault detection rates and its average fault detection rates of three monitoring statistics for eleven fault patterns reach 99.38 %, 99.15 % and 100 %, respectively.

Spatio-temporal feature extraction network based multi-performance indicators synergetic monitoring method for complex industrial processes

In the context of smart manufacturing, modern industrial processes are becoming increasingly complex in terms of process flows, product varieties, and performance indicators (PIs). Performance-driven process monitoring attracts extensive attentions in recent years. However, most methods require spatio-temporal correspondence between process variables and PIs, and rarely consider the correlation among various PIs. In this paper, a spatio-temporal feature extraction network-based multi-performance indicators synergetic monitoring framework is presented. Firstly, considering the missing data in PI measurements, a weighted sum of tensor nuclear norm (WSTNN) based batch-process data completion approach is developed, which can adeptly handle local missing and incomplete data issues and establish the spatio-temporal correspondence for subsequent modeling. Secondly, for a specific PI, a new canonical variate analysis embedded spatio-temporal convolutional network (CVA-STCN) is designed to extract the PI-related features with spatio-temporal dependency. Thirdly, considering the dynamic interaction of multiple PIs, a third-order feature tensor is established to perform the future fusion, and the correlations among various PI-related features are explored via tensor decomposition. Finally, a hierarchical multi-performance indicators synergetic monitoring model is developed over several subspaces. The proposed method is verified on Tennessee Eastman process and an actual hot strip mill process. Overall, the monitoring performance of the proposed method outperforms the traditional ones, in terms of higher fault detection rates and lower false alarm rates. Moreover, the information provided by the multi-subspace synergetic monitoring charts can offer valuable guidance to field engineers.

GENETIC AND TRAIT VARIABILITY OF GYRINICOLA REVEALS THE EXISTENCE OF AT LEAST FOUR SPECIES WITHIN THE UNITED STATES.

The tadpole-dwelling pinworm, Gyrinicola batrachiensis (Walton, 1929) Adamson, 1981 was recognized as the sole representative of the genus across Canada and the United States. However, evaluation of the morphology of these parasites across their range revealed considerable morphological variability that suggested diagnosable morphotypes. These morphotypes were associated with different species of anurans, several of which occurred in sympatry. Herein we use an extensive geographic sampling across the United States to obtain the morphotypes, screen their genetic diversity, and analyze this information using an integrative approach. We reconstructed their phylogeny using nuclear ribosomal partial genes 18S and 28S, ITS1, 5.8S, and ITS2, as well as 5 mitochondrial genes generated with Next-Generation sequencing technology. This phylogeny reveals 3 well-resolved lineages, which upon the use of a statistical approach (bPTP [Bayesian implementation of the Poisson tree processes]) supports the delimitation of 4 distinct groups equivalent to species. These putative species groups were tested using morphological characteristics paired with a MANOVA and canonical variate analysis. Results suggest that at least 4 species of Gyrinicola are present within North America, resulting in the resurrection of G. armatus (Walton, 1933) and the description of 2 new species.

Geometric morphometric analysis of beak shape of Columbimorphae (Columbas, Van, Mardin and Dönek).

Selective breeding over centuries has led to the emergence of numerous pigeon breeds from the single species Columba livia, showcasing unparalleled phenotypic diversity. In Eastern Turkey, Van pigeons originate, while Tumbler pigeon varieties thrive countrywide, reflecting local traditions. The avian beak, vital for survival, offers insights into domestication and traits influenced by natural selection. Geometric morphometrics, a shape analysis method, allows for a comprehensive examination of beak shapes among domestic pigeons, providing a nuanced understanding of their complexity. Understanding beak diversity in pigeons, especially those found in Turkey, enhances our knowledge of avian evolution and adaptation processes. The study utilized 48 skulls from 4 pigeon breeds, including wild rock pigeons and domestic pigeons of Tumbler, Mardin and Van breeds, all free from pathological lesions and adults. Geometric morphometric analyses of beak shape were conducted using dorsal and lateral photographs, with landmarks placed using tpsDig software. MorphoJ software facilitated procrustes analysis and principal component analysis (PCA) to assess morphological variability and differentiate pigeon breeds based on shape patterns, with significance set at p < 0.05. PCA revealed significant shape variations among pigeon breeds, with 47 principal components identified for lateral beak views and 36 principal components for dorsal views. Canonical variates analysis further distinguished morphological patterns among breeds, indicating distinct shape variations in both dorsal and lateral views, elucidating the unique characteristics of each breed's beak morphology. Our results demonstrate statistically significant differences in pigeon beak shape, particularly in the lateral view, confirming the importance of these variations (p < 0.05) and suggesting that such differences occur less than 5% of the time under the null hypothesis.

Variation in the Floral Morphology of Prosthechea karwinskii (Orchidaceae), a Mexican Endemic Orchid at Risk.

Prosthechea karwinskii is an orchid endemic to Mexico, threatened by the destruction of its habitat and the extraction of specimens to meet its demand for ornamental and religious use. Most of its populations, including the most locally abundant ones, are found in Oaxaca state. Variations in some floral traits have been observed in these populations. We implemented a morphometric analysis to assess their floral variation and identify the most significant characters in the morphological patterns of this orchid. Floral samples were collected from 17 populations of P. karwinskii in Oaxaca, as well as from specimens used as ornaments during Easter in an Oaxacan community (Zaachila), whose origin is unknown. Sampling of natural populations covered the environmental, geographic, and morphological variation of the species. We performed an analysis of variance (ANOVA), principal component analysis (PCA), canonical variate analysis (CVA), and cluster analysis, including 185 individuals and 45 variables (12 of them were discarded in the multivariate analyses due to high correlation). Characters of the column, lateral sepal, and labellum were most informative for the observed morphological patterns. Albarradas showed the greatest morphological differentiation, mainly due to the column. In general, individuals from the same locality tended to overlap more, especially the populations of Jaltianguis and Yahuiche, which were different from the geographically close population of Etla. Teposcolula presented the highest values in perianth characters, unlike Sola_Rancho Viejo. The specimens recovered from religious ornaments were morphologically more similar to those from Yanhuitlan and Etla. This morphometric analysis identified characters as potential taxonomic markers for P. karwinskii and related species, showing its potential to associate specimens of unknown origin with their probable geographical region. Our work encourages working on collaborative conservation strategies to ensure the long-term permanence of both the species and its traditional uses.

Craniometric Relationships of Migrant Victims of the April 18, 2015 Shipwreck Off the Coast of Libya

One of the most tragic events involving African migrants’ attempts to get to Europe was the 2015 shipwreck off the coast of Libya. More than 300 crania were recovered and are currently in the Laboratory of Forensic Anthropology and Odontology, Milan, Italy, where attempts are being made to identify them. This paper analyzes the cranial morphometrics in relation to what is known of African cranial variation. It also addresses questions of population subdivision on the ship as well as secular changes that may be reflected in cranial morphology.Crania were digitized using the 3skull software, which also computes Howells measurements from the coordinates. Migrant crania were compared to African reference samples consisting of both 19th-century sub-Saharan West Africans and East Africans. Statistical procedures were discriminant and canonical variate analysis and Mahalanobis distances. K-means unsupervised clustering was also used.Results showed that the migrant samples differed from the 19th-century samples systemically; the differences consisted mainly of lower facial projections and higher cranial vaults and bases. Position on the ship, whether on the deck or below in the holds, showed subdivision. Holds had a higher proportion of West Africans, and the deck had a higher proportion of East Africans. K-means clustering also found groups contrasting between the deck and the holds. Comparing migrant cranial morphology to 19th-century Africans using variables that respond to secular change showed that migrants reflect changes that have occurred in Africa over the past 200 years.We conclude that morphometric analysis can provide useful information concerning the composition of unidentified victims of tragic events such as the 2015 shipwreck.

Osteon shape variation in the femoral diaphysis: A geometric-morphometric approach on human cortical bone microstructure in an elderly sample.

Geometric morphometrics (GMM) have been applied to understand morphological variation in biological structures. However, research studying cortical bone through geometric histomorphometrics (GHMM) is scarce. This research aims to develop a landmark-based GHMM protocol to depict osteonal shape variation in the femoral diaphysis, exploring the role of age and biomechanics in bone microstructure. Proximal, midshaft, and distal anatomical segments from the femoral diaphysis of six individuals were assessed, with 864 secondary intact osteons from eight periosteal sampling areas being manually landmarked. Observer error was tested using Procrustes ANOVA. Average osteonal shape and anatomical segment-specific variation were explored using principal component analysis. Osteon shape differences between segments were examined using canonical variate analysis (CVA). Sex differences were assessed through Procrustes ANOVA and discriminant function analysis (DFA). The impact of osteonal size on osteonal shape was investigated. High repeatability and reproducibility in osteon shape landmarking were reported. The average osteon shape captured was an elliptical structure, with PC1 reflecting more circular osteons. Significant differences in osteon shape were observed between proximal and distal segments according to CVA. Osteon shape differed between males and females, with DFA showing 52% cross-validation accuracies. No effect of size on shape was reported. Osteonal shape variation observed in this study might be explained by the elderly nature of the sample as well as biomechanical and physiological mechanisms playing different roles along the femoral diaphysis. Although a larger sample is needed to corroborate these findings, this study contributes to the best of our knowledge on human microanatomy, proposing a novel GHMM approach.

Canonical variate residual analysis for industrial processes fault detection

AbstractWith the rapid development of intelligent integration in industrial processes, a challenge emerges. Early failures cannot be detected in a timely manner, potentially leading to significant financial losses. While traditional canonical variate analysis (CVA) methods are effective for dynamic process monitoring, they may lack the flexibility required for early fault detection. To address this challenge, a fault detection method based on canonical variate residual analysis (CVRA) is proposed. CVRA introduces a distinctive residual statistic that preserves critical information about the data. It places heightened focus on the primary components of the data, capturing core features of system changes and enhancing sensitivity to early anomalies. Additionally, by incorporating the geometric properties of the Manhattan distance, it mitigates statistical data errors, thereby improving detection accuracy. Simulation results validate the method's effectiveness in the Tennessee Eastman (TE) process. Furthermore, the successful application of the three‐phase flow facility provides a benchmark for evaluation using real process data.

Molecular identification and morphological variations of Amblyomma lepidum imported to Egypt, with notes about its potential distribution under climate change

The tick Amblyomma lepidum is an ectoparasite of veterinary importance due to its role in transmitting livestock diseases in Africa, including heartwater. This study was conducted in 2023 to monitor Amblyomma spp. infestation in dromedary camels imported from Somalia, Ethiopia, and Sudan to Egypt. This study inspected 200 camels at the Giza governorate’s camel market that had been imported from Somalia, 200 from Ethiopia, and 200 from Sudan for tick infestation. Specimens were identified using morphological characteristics and phylogenetic analyses of the 12S and 16S rRNA genes. Clusters were calculated using an unweighted pair-group method with arithmetic averages (UPGMA) dendrogram to group the specimens according to their morphometric characteristics. The morphometric analysis compared the body shape of ticks collected from different countries by analyzing dorsal features. Principal component analysis (PCA) and canonical variate analysis (CVA) were performed to obtain body shape variation among specimens from different countries. Results indicated that camels were infested by 57 males Amblyomma lepidum, and no female specimens were observed; among these specimens, one may have a morphological abnormality. The results suggest that A. lepidum specimens collected from camels imported to Egypt from African countries exhibit locally adapted morphology with variations among specimens, particularly variations in body size. This adaptation suggests minimal potential for genetic divergence. Ecological niche modeling was used to predict the areas in Africa with suitable climates for A. lepidum. The study confirmed that East African countries might have the most favorable climatic conditions for A. lepidum to thrive. Interestingly, the amount of rain during the wettest quarter (Bio16) had the strongest influence on the tick’s potential distribution, with suitability decreasing sharply as rainfall increased. Future predictions indicate that the climatic habitat suitability for A. lepidum will decrease under changing climate conditions. However, historical, current, and future predictions indicate no suitable climatic habitats for A. lepidum in Egypt. These findings demand continuous surveillance of A. lepidum in camel populations and the development of targeted strategies to manage tick infestations and prevent the spread of heartwater disease.

Bill shape variation in selected species in birds of prey.

At the top of many ecosystems, raptors, also known as birds of prey, hold major influence. They shape their surroundings through their powerful hunting skills and complex interactions with their environment. This study investigates the beak morphology of four prominent raptor species, Golden eagle (Aquila chrysaetos), Common buzzard (Buteo buteo), Peregrine falcon (Falco peregrinus) and Common kestrel (Falco tinnunculus), found in Türkiye. By employing geometric morphometric methods, we investigate shape variations in the beaks of these species to unravel the adaptive significance of their cranial structures. This analysis reveals distinct beak morphologies among the studied raptors, reflecting adaptations to their feeding habits, hunting techniques and ecological niches. The results from Principal component analysis and Canonical variate analysis demonstrate significant differences in beak morphology between the Falconiformes and Accipitriformes clades, as well as among all three groups. The overall mean beak shapes of Golden Eagles are quite similar to Common Buzzards, with both species having longer beaks. In contrast, Falcons exhibit a distinctly different beak morphology, characterized by wider and shorter beaks. Changes in beak shape can lead to changes depending on the skull. It is thought that skull shape variations among predator families may have an impact on beak shape. These findings highlight the importance of integrating morphometric analyses with ecological insights to enhance our understanding of the evolutionary processes shaping raptor beak morphology.

Shape variations of pelvis in different classes of dogs using geometric morphometry.

The ossa coxae are the bones that connect the hindlimbs to the axial skeleton. The right and left os coxae join at the median plane to form the pelvis. In this study, variations in pelvis shape and the asymmetric structure of the pelvis were investigated across different classes of dogs. To achieve this, computed tomography images of the pelvis were obtained from 35 dogs, and 3D modelling of the pelvis was created. Subsequently, 45 landmarks were identified on these models. As a result of the Principal Component Analysis, the shape variation was observed in the pelvic canal and crista iliaca. Directional asymmetry between Principal Component 1 and Principal Component 2 accounted for 33.84% of the total variation, while fluctuating asymmetry contributed 23.66%. Canonical variate analysis revealed that canonical variate (CV) 1 explained 56.56% of the total variation between groups, with CV 2 explained 28.98%. Male dogs exhibited greater pelvic variation than females. Procrustes ANOVA indicated that the greatest proportion of shape variation corresponds to the effect of differences among individuals. While directional asymmetry was statistically significant, fluctuating asymmetry was not. Male dogs displayed more pronounced pelvic shape asymmetry, typically towards the right. Gundogs had a narrower pelvic canal and a wide crista iliaca, whereas terriers had a wider pelvic canal and smaller crista iliaca in shape. Geometric morphometry enables statistical analysis and the derivation of average shapes from samples, making it a vital tool in veterinary anatomy. This study provides insights into pelvic geometric morphometry across different classes of dogs.

Morphometric Anatomical Points of Fruit Fly (Bactrocera dorsalis Complex) using Generalized Procrustes Analysis Model

This study aims to analyze the morphometric anatomical wings of the fruit fly Bactrocera dorsalis Complex. The species used in this study consisted of 11 (eleven) species. The analysis technique of the wings of Bactrocera dorsalis Complex, i.e. the right wing of each individual was analyzed using Morphometric landmarks with 15 anatomical points. Digital images of wings are scaled in size and scale using Adobe Photoshop CS3 software. The results of anatomical point digitization are processed into MorphoJ software v. 1.06b. Digitization data of anatomical points of wing shape was collected using Generalized Procrustes Analysis (GPA). The results of the Canonical Variate Analysis (CVA) showed that there was a grouping of each species. The grouping of Bactrocera dorsalis complex wing types is based on the similarity of the percentage of cumulative values of CVA1 and CVA2 tests. Groups B. carambolae, B. minuscula, B. occipitalis, B. papayae, B. floresiae, B. philippinennsis, Bactrocera sp. 23, Bactrocera sp. 25, and Bactrocera sp. 26 grouped because they have similarities in wing venation. The difference in wing venation is found in Bactrocera sp. 27 and B. sumbawaensis because they are far from the group B. carambolae, B. minuscula, B. occipitalis, B. papayae, B. floresiae, B. philippinennsis, Bactrocera sp. 23, Bactrocera sp. 25, and Bactrocera sp. 26.

Using shell shape analysis based on landmarks to trace the geographical origin of the common cockle (Cerastoderma edule)

Determining the geographical origin of seafood is crucial for regulators and fishing industries who seek to prevent commercial fraud, enforce food safety regulations, and encourage high standards in sustainable fisheries management. The cockle, Cerastoderma edule (Linnaeus 1768), is a key species in estuarine ecosystems and is harvested all over Europe. Therefore, traceability tools using quick and inexpensive techniques to identify the origin of this bivalve are of paramount importance to support law enforcement. In this work, we explore the potential of using Geometric Morphometric (GM) methods to identify the geographical origin of cockle specimens. This method is based on landmarks identified in the shell to trace the origin of specimens obtained in nearby aquatic systems (from <35 km to <250 km distance). Specimens were collected in five aquatic systems (Ria de Aveiro, the Tagus and Sado estuaries, and the Albufeira and Óbidos coastal lagoons) in Portugal. Shells were digitalized and 16 landmarks were identified in each right valve and analyzed using Generalized Procrustes Superimposition. The discriminating power for traceability of 12 statistical and machine learning methods was assessed based on the corresponding shape variables, using R and Python (Linear Discriminant Analysis (LDA), Canonical Variable Analysis (CVA), Principal Component Analysis (PCA), Between-Group PCA (bgPCA), Partial Least Squares Discriminant (PLSD), Classification Regression Tree (CRT), Logistic Regression (LR), Random Forest (RF), Gradient Boosting (GB), K Nearest Neighbors (KNN), Support Vector Machines (SVM), Extending Gradient Boosting (XGBoost) and Neural Networks (NNET). LDA, CVA, SVM, and NNET demonstrated greater accuracy and a F1-score >80%, even with a small and unbalanced sample size. The highest percentage of correctly assigned individuals was obtained in the Tagus estuary (mean 89%) and in the Albufeira lagoon (mean 93%), which were also the systems with more specimens measured (174 and 59 respectively), whereas the worst results were obtained in the Sado estuary (50%, 56 specimens). In the Albufeira coastal lagoon, the best classification methods reached 100% correct classifications. It further highlights the importance of establishing statistical standards, such as the ones developed in the current work, to evaluate different methods, as small changes in the procedure may cause substantial differences in the results and conclusions. The revision of previous works (presented as a table) showed often >90% of correct classification in both bivalves and gastropods, highlighting the potential of the techniques for other mollusks. Our results support the use of GM based on landmarks as a reliable tool for bivalve's traceability, since it is a quick, simple and inexpensive approach. Further research should extend these findings to other species and other shape analysis techniques.

Linear measurements and shape analysis in the calcaneus of selected dog breeds.

The vast array of dog breeds showcases a remarkable diversity that extends to osteological differences. Exploring these morphological distinctions and establishing reference data for various dog breeds are essential steps in comprehending the evolutionary changes that dogs have undergone. In this study, we conducted linear measurements of the calcaneus and performed shape analyses on selected dog breeds to elucidate distinctive characteristics among them. X-ray images of the calcaneus from six different dog breeds-Maltese Terrier, Toy Poodle, Pomeranian, Cavalier King Charles Spaniel, French Bulldog and Golden Retriever-were utilized for this investigation. Radiological images were obtained from a medio-lateral exposure, positioned 30 cm away from the x-ray device. From these images, four linear length measurements and two angle values were extracted. Additionally, a 2D geometric morphometric analysis was conducted using 32 semi landmarks placed on the radiological images. Linear measurements were assessed using ANOVA, while principal component analysis was employed to examine shape variations across all individuals. Shape differences between species were further elucidated through canonical variates analysis. The results revealed that the Golden Retriever exhibited the highest values for linear measurements, while the Pomeranian showed the lowest. Maltese Terriers displayed the highest dorsal calcaneal angle value. Notably, there were significant differences in calcaneal body length among all breeds, except for the Toy Poodle and Cavalier King Charles Spaniel. Moreover, Maltese Terriers exhibited statistically distinct angular measurements compared to other breeds. Principal component analysis unveiled that the first principal component explained 32.69% of the total variation, with the cranial edge of the calcaneal body being closer to the body in individuals with higher values. Shape variations also indicated that Golden Retrievers displayed a broader range of shapes compared to French Bulldogs, which exhibited a more conservative distribution. While there was no clear breed-specific distinction according to the first principal component, Cavalier King Charles Spaniels generally showed lower values. In canonical variates analysis, distinctions in calcaneal shape between species were apparent, with Golden Retrievers, Cavalier King Charles Spaniels and French Bulldogs displaying positive values for the first canonical variates. The highest Procrustes distance was observed between Maltese Terriers and Cavalier King Charles Spaniels. Notably, allometry was found to be statistically insignificant. This comprehensive study utilized both linear and geometric morphometric analyses based on x-ray images, yielding promising results. The integration of imaging systems in veterinary anatomy research presents numerous opportunities for studying animal welfare and health, utilizing various materials such as bones and cadavers. These advancements hold the potential for further enhancing our understanding of animal morphology and well-being.

Morphological variation of Oreochromis niloticus (Lacépède, 1803) populations in stressed environment: Middle stream of Comoé River (Ivory Coast)

This work aims to assess the influence of environmental stress in the middle course of the Comoé River on the morphological characteristics of Oreochromis niloticus populations using the geometric morphometric approach. A total of 248 specimens of O. niloticus were collected from four sites (M'Basso, YèrèYèrè, Abradinou and Bettié). No specimen of O. niloticus has been collected from the Manzan River, which has a high level of gold panning activity. Nineteen (19) homologous landmarks were digitized on each individual. Data were studied using principal component analysis, canonical variable analysis, discriminant function analysis and allometric analysis. The PC1 and PC2 axes show an extension of the deformation grids at the level of the head and the caudal and dorsal fins. However, the PC3 axis almost exhibits a deformation grid that deforms at the caudal fin, pectoral fin, and dorsal fin. The results of the various analyzes showed significant differences between the morphology of the populations studied. These differences were observed mainly in the head, dorsal and pectoral fins. The disturbance of aquatic habitats has an impact on the morphology of specimens of O. niloticus from the middle course of the Comoé River. A slight deformation is recorded in the individuals of O. niloticus at M'Basso, considered the least disturbed site. On the other hand, a strong deformation is observed in specimens from the YèrèYèrè, Abradinou and Bettié sites which are more disturbed.

Dung beetle populations's morphology show evidence of isolation in southern Brazil islands

AbstractInsects in islands may undergo morphological variations related to the geographic isolation faced by their populations. This isolation on insular biota can vary according to the history and characteristics of the islands, as well as the dispersal ability of each species. We investigated the existence of morphological variations in the populations of the Canthon rutilans cyanescens dung beetle from the southern Brazil islands and the nearby mainland. Dung beetles were sampled from December/2020 to April/2021 from five Islands in the Santa Catarina Archipelago and on the mainland through samplings with baited live traps. With geometric morphometry analyses and individuals from each population we compared the body size using an Analysis of Variance and body shape using a Discriminant Analysis with cross‐validation test, followed by a Canonical Variable Analysis to visualize the populations in morphometric space. We found a significant difference in the body length: the population of Ratones Grande Island has smaller individuals than the populations of the mainland, Dona Francisca Island, and Peri on Santa Catarina Island. We also observed that the body shape of the population of Campeche Island differs from the populations of Arvoredo Island and Dona Francisca Island, with a slightly oval body, a larger dorsal region, and a retracted abdomen. These results are consistent with the hypothesis that the populations found on the islands may have remained there since their formation after the Last Glacial Maximum. The isolation and the absence of connectivity between the populations would explain why some islands have populations with distinct morphology.Abstract in Portuguese is available with online material.

Association between the three-dimensional facial shape and its color in a boundary group of young to middle-aged Asian women

Visual cues strongly influence an individual's self-esteem and have fundamental sociopsychological functions. The color and shape of the face are important information for visual cues and are hypothesized to be correlated with each other. However, few studies have examined these relationships. Thus, this study determined the association between color and shape of the face. For this purpose, we evaluated Chinese women in their 30s and 40s (n = 166). Three-dimensional (3D) image-capture devices that provide shape morphology along with standardized photographs (color information) were used to obtain 3D images of women. The coordinates and red‒green–blue color data on the 3D images were utilized to perform principal component (PC) analysis, and shape and color PCs were generated. A canonical variate analysis was then conducted to check for significant correlations between the shape and color PCs. As a result, 6 significant correlations were found (p < 0.05). In detail, in addition to the physical correlations (i.e., steric faces or faces with protrusion of the cheek showed greater shadows, retrognathism was related to a shadow under the lower lip and vice versa), biological correlations (fatty faces showed greater redness and remarkable marionette lines; faces with age-related sagging showed greater darkness, possibly related to cumulative ultraviolet radiation exposure of the skin; and robust mandibles and supraorbital ridges were related to thick eyebrows) were found. This insight can aid both medical and cosmetic practitioners in comprehending the intricate details conveyed by facial features, thereby facilitating more comprehensive diagnosis and treatment planning, including makeup.