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Phenotypic variations in fish body and scale shape were investigated among the three populations of Aphanius dispar (Ruppell, 1829)in Southern Iran through the use of landmark-based geometric morphometric analyses. This species is widely distributed in the region, and therefore, considerable morphological variations exist among the geographically allopatric populations. Based on the Principle Component Analysis (PCA), variation in body shape of the females is prominently related to the dorsal fin region, while in the males it is related to the dorsal fin and caudal peduncle. Moreover, the shape variations in the scales are obviously linked to the tip of anterior portion of the scales, and the left and right boundaries between anterior and posterior regions of the scales. The lateral sides of the fish scales in site I are concave, while they are laterally convex in sites II and III. The observed variation seen in the fish body shape and scales among the three studied sites are probably caused by the different ecological conditions of their habitats particularly variation in water flow.

Bergmann's rule relates the trend of increasing body size with higher latitudes, where colder climates are found. In the Mexican Pacific, three marine ecoregions are distinguishable across a latitudinal gradient. Stenoplax limaciformis is an abundant chiton species that is distributed on rocky shores in these ecoregions. Geometric morphometric analyses were performed to describe the shape and size variation of S. limaciformis between marine ecoregions that vary in sea surface temperature with latitude, thus testing Bergmann's rule. Individuals' body shape ranged from elongated to wide bodies. Although there was variation in chitons' body shape and size, the was no evidence of allometry among localities. The Gulf of California is the northernmost ecoregion evaluated in this work, where larger chitons were observed and lower sea surface temperature values were registered. The results suggest that S. limaciformis follows a trend to Bergmann's rule, such as endotherms. These mollusks do not need heat dissipation, but they do need to retain moisture. In addition, larger chitons were observed in zones with high primary productivity, suggesting that chitons do not delay their maturation due to food shortage.

The geometric morphometric analysis of shape variation in complex biological structures such as the human skull poses a number of specific challenges: the registration of homologous morphologies, the treatment of bilateral symmetry, the graphical representation of form variability in three dimensions and the interpretation of the results in terms of differential growth processes. To visualize complex patterns of shape change, we propose an alternative to classical Cartesian deformation grids in the style of D'Arcy W. Thompson. Reference to the surface structures of the organism under investigation permits a comprehensive visual grasp of shape change and its tentative interpretation in terms of differential growth. The application of this method to the analysis of human craniofacial shape variation reveals distinct modes of growth and development of the neurocranial and viscerocranial regions of the skull. Our data further indicate that variations in the orientation of the viscerocranium relative to the neurocranium impinge on the shapes of the face and the cranial vault.

The morphological features of an organism are an important source ofinformation for many areas of biological study. Insect wing architectural designis believed to be an excellent system for studying morphological variation becauseof their firm or solidly cleared structures. It has been the center of geometricmorphometric investigation in the past since insect’s wing pattern can providedetails on their evolutionary history and flight performance. Wing shape andsize disparity of fifty-nine individuals of bumblebee was explored to explain andfigure out biological structure variation within similar species. Examination inboth left and right forewings and hind wings was also considered to find out ifphenotypic sexual dimorphism exists. The outline-based geometric morphometrictechnique was employed in this study to measure and evaluate wing shape andsize variation among bumblebees. Results from mean shapes and scatter plotdiagrams analysis revealed that individuals of bumblebee differ less with respect to shape. Overlapping of individuals is visible on both wings in both sexes, which shows absence of dimorphism. Male individuals have larger forewings comparedto females. Slight variation was observed for both sexes in terms of hind wings,which indicates that both individuals exhibit common size characteristic andabsence of dimorphism. The study concludes that size may be considered as abasis for sex determination and that wing size is somewhat a sexual dimorphictrait among bumblebee species. Keywords - Biology, wing morphometry, outline-based geometric morphometric analysis,Philippines

Understanding human body type and shape variations is of fundamental importance in various ergonomic applications in a wide range of industries. This article provides a comprehensive analysis of the body types in various countries using the most recent national sizing standards. A set of integrated and internationally compatible size tables are then derived, which provide a valuable reference for analysis of body shape variation. This study covered both female and male sizing standards of the US, Europe, China, Japan and some other countries. The statistical analysis showed that size frequency varies from various countries with significant differences in body types and shapes. The standards of China and Japan covered the smaller body dimensions and sizes, as reflected in the relatively narrow torso and hips. The Europe and US standards covered the relatively large body dimensions and size ranges; the body shapes are plumper and wider than those of other countries.

Taxonomy and systematic of fossil hog-nosed skunks, genus Conepatus (Carnivora: Mephitidae) from Argentina

Measurements of human body size and shape are an important source of information for a range of scientific fields and applications; however, practitioners still rely on traditional tools and methods which limit the kinds of measurements that can be taken. Recent literature has suggested that 3D imaging technology is a more sophisticated tool that could enable the comprehensive characterisation of human body shape. The aim of this programme of doctoral study was to determine whether shape anthropometrics can complement existing techniques in the assessment of human morphology. A novel analytical procedure was developed using geometric morphometrics and statistical shape analysis methods to extract numeric parameters from 3D imaging data, which describe scale-invariant characteristics of human torso shape. Though errors in anatomical landmark identification and participant scanning posture can affect the acquisition of shape anthropometrics, the developed methods were found to have high test-retest reliability, suitable for use within subsequent investigations. A series of investigations were conducted to determine whether shape measures provide additional information which is not captured by existing anthropometric techniques. The findings of these investigations suggest that body shape measures show a complex dependence on body size. Though certain shape features demonstrate a degree of allometric scaling and change with increases in body size, there are significant proportions of shape variation which cannot be explained by existing anthropometrics. These non-allometric variations in body shape have been shown to improve the estimation of subcutaneous abdominal adiposity in a small cohort of participants, and have demonstrated the potential for misclassification of individuals using existing indices, such as BMI and WHR. This programme of research provides a more detailed understanding of human morphological variation, which could inform the development of improved tools for characterising how body shape relates to its underlying mass distribution.

Simple SummaryThis study aims to assess the relationship between morphology and metabolism during the ontogenetic development of Chelon auratus. The geometric morphometric analysis allowed us to identify morphological variations in the transformation from larvae to juveniles and to establish the growth patterns of each stage. According to our results, the ETS activity is linked to the individual morphology, specifically to the body size and to the posterior area.The fish body shape is a key factor that influences multiple traits such as swimming, foraging, mating, migrations, and predator avoidance. The present study describes the body morphological changes and the growth trajectories during the transformation from 24 to 54 days post-hatching in the golden grey mullet, Chelon auratus, using geometric morphometric analysis (GMA). The results revealed a decrease in morphological variability (i.e., morphological disparity) with the somatic growth. The main changes affected head size, elongation, and widening of the body. Given that this variability could affect the metabolism, some individuals with different morphologies and in different ontogenetic developmental stages were selected to estimate their potential respiration rate using the Electron Transport System (ETS) analysis. Differences were detected depending on the developmental stage, and being significantly smaller after 54 days post-hatching. Finally, a multivariate linear regression indicated that the specific ETS activity was partially related to the fish length and body shape. Thus, our findings emphasized the relevance of larval morphological variability for understanding the physiological processes that occur during the development.

The population consequences of sexual selection remain empirically unexplored. Comparative studies, involving extinction risk, have yielded different results as to the effect of sexual selection on population densities make contrasting predictions. Here, we investigate the relationship between sexual dimorphism (SD) and population productivity in the seed beetle Callosobruchus maculatus, using 13 populations that have evolved in isolation. Geometric morphometric methods and image analysis are employed to form integrative measures of sexual dimorphism, composed of variation in weight, size, body shape, and pigmentation. We found a positive relationship between SD and adult fitness (net adult offspring production) across our study populations, but failed to find any association between SD and juvenile fitness (egg-to-adult survival). Several mechanisms may have contributed to the pattern found, and variance in sexual selection regimes across populations, either in female choice for "good genes" or in the magnitude of direct benefits provided by their mates, would tend to produce the pattern seen. However, our results suggest that evolutionary constraints in the form of intralocus sexual conflict may have been the major generator of the relationship seen between SD and population fitness.

The Bauru Group is a sedimentary sequence of the Paraná Basin, dated to the Late Cretaceous. Its palaeofaunistical assemblage includes a rich record of turtles of the lineage Podocnemidoidae, but many of the taxa that have been described from this geologic unit have an uncertain taxonomy. An example is the species “Podocnemis” brasiliensis, known from a single fragmentary plastron and regarded by many authors as a nomen dubium. The discovery of specimen FFP PG 218, comparable to “Podocnemis” brasiliensis, permitted the attribution of this specimen to this taxon, adding to its hypodigm. The new fossil preserves anatomical parts that are lacking in the type specimen of “P.” brasiliensis, permitting an amendment to the species’ diagnosis, with the addition of new diagnostic characteristics. With the new diagnosis, it was possible to revisit specimens that had been attributed to the species “P.” brasiliensis in the past, and assess whether they could really be attributed to this taxon. The revision showed that none of the past attributions can be confirmed. However, there are two occurrences of specimens similar to “P.” brasiliensis that were compared to this species through the use of open taxonomy modifiers, indicating the uncertainty behind these associations. A geometric morphometric analysis was performed using the epiplastra of the turtles of the Bauru Group, with the aim of evaluating the shape variation of this structure. The analysis recovered considerable variation described by three principal components, linked mainly to changes in the width of the intergular scute and the length of the epiplastron as a whole. The morphometric analysis also corroborated the current taxonomy of Bauru Group forms, organizing the sampled individuals in a way similar to the previously proposed taxonomic groupings, with “P.” brasiliensis appearing as a distinct taxon. To assess the relevance of shell thickness as a diagnostic characteristic in alpha- taxonomy, correlation tests and linear regressions were run using a sample of living and extinct Podocnemidoidae, as well as subsets for three taxa of the Bauru Group. It was not possible to make a subset out of “P.” brasiliensis due to the small number of available specimens. The analysis indicated that the shell of Roxochelys wanderleyi is proportionally thicker than that of other Podocnemidoidae. Still, the results show that the proportional thickness of the shell exhibits considerable intra- specific variation, and that the allometric effect of the regressions recovered from the whole sample and the subsets is rather subtle, not very different from isometry. Keywords: podocnemidoidae; bauru group; geometric morphometric analysis; epiplastron; shell thickness; alpha-taxonomy

In aquatic insects, body size and shape are key traits that may indicate phenotypic plasticity or adaptations to their hydrological landscape. Liodessus chilensis is a small and poorly-known aquatic beetle that inhabits permanent and temporary bodies of water. Accompanying the report of the species in different habitats of Navarino Island, an update of its description is presented. Additionally, body shape variation of different populations of L. chilensis is evaluated. Geometric morphometric analysis and multivariate regressions on the body shape of L. chilensis show variation mainly in the posterior part of the elytra and could indicate plasticity linked to the nature of the habitats in which they occur. The population of temporary pools presents shorter and broader elytra in their terminal part, while those that inhabit peat bogs and wetlands are longer and elongated. Additionally, a positive allometric effect was found, indicating that in addition to the differences in body shape, populations inhabiting temporary pools tend to be smaller in size. The plasticity of forms of L. chilensis as well as their permanent and temporary habitats can be considered as sentinels of environmental changes. These results are relevant for the Magallanes region, which has recently been declared prone to drought.

BackgroundWithin-species skull shape variation of marsupial mammals is widely considered low and strongly size-dependent (allometric), possibly due to developmental constraints arising from the altricial birth of marsupials. However, species whose skulls are impacted by strong muscular stresses – particularly those produced through mastication of tough food items – may not display such intrinsic patterns very clearly because of the known plastic response of bone to muscle activity of the individual. In such cases, allometry may not dominate within-species shape variation, even if it is a driver of evolutionary shape divergence; ordination of shape in a geometric morphometric context through principal component analysis (PCA) should reveal main variation in areas under masticatory stress (incisor region/zygomatic arches/mandibular ramus); but this main variation should emerge from high individual variability and thus have low eigenvalues.ResultsWe assessed the evidence for high individual variation through 3D geometric morphometric shape analysis of crania and mandibles of three species of grazing-specialized wombats, whose diet of tough grasses puts considerable strain on their masticatory system. As expected, we found little allometry and low Principal Component 1 (PC1) eigenvalues within crania and mandibles of all three species. Also as expected, the main variation was in the muzzle, zygomatic arches, and masticatory muscle attachments of the mandibular ramus. We then implemented a new test to ask if the landmark variation reflected on PC1 was reflected in individuals with opposite PC1 scores and with opposite shapes in Procrustes space. This showed that correspondence between individual and ordinated shape variation was limited, indicating high levels of individual variability in the masticatory apparatus.DiscussionOur results are inconsistent with hypotheses that skull shape variation within marsupial species reflects a constraint pattern. Rather, they support suggestions that individual plasticity can be an important determinant of within-species shape variation in marsupials (and possibly other mammals) with high masticatory stresses, making it difficult to understand the degree to which intrinsic constraints act on shape variation at the within-species level. We conclude that studies that link micro- and macroevolutionary patterns of shape variation might benefit from a focus on species with low-impact mastication, such as carnivorous or frugivorous species.

Classifying camel breeds using geometric morphometrics: A case study in Kuwait

BackgroundCorrect species identification of blow flies is a crucial step for understanding their biology, which can be used not only for designing fly control programs, but also to determine the minimum time since death. Identification techniques are usually based on morphological and molecular characters. However, the use of classical morphology requires experienced entomologists for correct identification; while molecular techniques rely on a sound laboratory expertise and remain ambiguous for certain taxa. Landmark-based geometric morphometric analysis of insect wings has been extensively applied in species identification. However, few wing morphometric analyses of blow fly species have been published.MethodsWe applied a landmark-based geometric morphometric analysis of wings for species identification of 12 medically and forensically important blow fly species of Thailand. Nineteen landmarks of each right wing of 372 specimens were digitised. Variation in wing size and wing shape was analysed and evaluated for allometric effects. The latter confirmed the influence of size on the shape differences between species and sexes. Wing shape variation among genera and species were analysed using canonical variates analysis followed by a cross-validation test.ResultsWing size was not suitable for species discrimination, whereas wing shape can be a useful tool to separate taxa on both, genus and species level depending on the analysed taxa. It appeared to be highly reliable, especially for classifying Chrysomya species, but less robust for a species discrimination in the genera Lucilia and Hemipyrellia. Allometry did not affect species separation but had an impact on sexual shape dimorphism.ConclusionsA landmark-based geometric morphometric analysis of wings is a useful additional method for species discrimination. It is a simple, reliable and inexpensive method, but it can be time-consuming locating the landmarks for a large scale study and requires non-damaged wings for analysis.

A key question in ecological speciation is to understand the causes and consequences of phenotypic divergence among populations. In this work, we analyzed the body shape and size variation in Jenynsia lineata across different coastal habitats along the Atlantic coast of South America. We hypothesized that J. lineata presents morphological variations to inhabit contrasting environments and that these adaptations are sex specific. We analyzed 13 populations from five coastal habitats, using linear and geometric morphometry, and tested the correlation of body shape variation with environmental variables to understand which environmental factors may influence body shape and size variation. Jenynsia lineata showed differences in body shape and size among populations, and these differences are specific to each sex. While females showed a variation in the caudal peduncle correlated with water current, we did not find such trait variation and correlation in males. Alternatively, individuals from marine rocky pools have a convex body curvature along the dorsal profile and larger body sizes, in both sexes. With these results, we describe the shape and size morphological variation of J. lineata and discuss this uncommon habitat-dependent sexual dimorphism in a Neotropical livebearer fish.