Morphometric Variables Research Articles

From footprint morphometrics to the stature of fossil hominins: A common but uncertain estimate

Hominin footprints are a particular remain in paleoanthropology representing brief moments of life of extinct individuals. Footprints not only provide information on the locomotor behavior of fossil taxa but also on their body characteristics such as their stature. This stature is usually estimated from the length of the footprints based on the well-known foot length to stature ratio. However, footprint length does not result only from the foot length but of a combination of factors. Therefore, it is necessary to investigate the relationships between footprint length and stature of individuals using experimental approaches. Secondly, recent discoveries of fossil footprints have led to the estimation of statures from isolated footprints. However, such estimates may be biased because of the intraindividual morphometric variation of the footprints. Moreover, footprints may also be incomplete making it impossible to measure the length and therefore the estimation of a stature. The search for relationships between stature and other morphometric variables is therefore necessary to have the most accurate picture possible of the individuals who left these tracks. In this context, this article reports the results of an experimental study that aims to determine the relationships between the stature of individuals and different morphometric variables and to quantify the intraindividual variation of each variable. Thus, 21 morphometric variables were measured on a total of 175 experimental footprints left by 20 individuals in an experimental area composed of loose sand. Statistical analyses show that footprint lengths are not only the variables most correlated with stature but also those with the least intraindividual variation. However, estimation of stature from footprints left by fossil hominins is subject to three types of uncertainties: residuals from linear regression, intraindividual variation that can be particularly large in soft substrates, and the application of relationships defined on modern populations to fossil taxa.

An integrative insight into the diversity, distribution, and biogeography of the freshwater endemic clade of the Ponticola syrman group (Teleostei: Gobiidae) in the Caucasus biodiversity hotspot.

Freshwater habitats of the Caucasus biodiversity hotspot represent a center of endemism for the gobiid genus Ponticola Iljin, 1927. Hitherto, large‐scale molecular studies, owing to restricted taxon and geographical sampling, have failed to give an elaborate picture of diversity and evolutionary history of these species. Here, to contribute to filling this gap, we assessed taxonomic diversity, phylogeography and evolutionary history for the south Caspian populations of Ponticola presently classified as P. iranicus and P. patimari, using an integrative taxonomic approach comprising an entire geographic range sampling, and analyses of mitochondrial DNA haplotypes, the head lateral line system, otolith shape, and meristic and morphometric variation. All freshwater samples of the P. syrman group belong to a monophyletic clade with two main subclades: a small subclade confined to the upper Sefidroud sub‐basin including the type locality of P. iranicus and a large subclade with three geographically constrained haplogroups (Hg1, Hg2, and Hg3), comprising the rest of the distribution. Hg1 showed an eastern distribution including the type locality of P. patimari, while Hg2 and Hg3 are sister groups with central and western‐central distributions, respectively. The freshwater clade diverged from P. syrman during the Tyurkyanian low stand (~150 m b.s.l. lasting ~0.1 Myr), while the divergence of P. iranicus and P. patimari and radiations within P. patimari took place during the Bakunian high stand (up to 50 m a.s.l. lasting ~378–480 kya). Species delimitation analyses indicated two distinct species, corresponding to each main subclade. Although the otolith shape and lateral line analyses did not reflect with phylogeographic pattern, PCA and DFA plots of meristic and morphometric data showed a clear separation of the two major subclades corresponding to P. iranicus and P. patimari, suggesting the presence of significant morphological variation meriting formal taxonomic recognition. Overall, our findings (i) reveal the presence of two freshwater endemic species in the P. syrman group, and pending further investigation, hypothesize the presence of a third cryptic species; (ii) revise and document a narrow distributional range and low diversity for P. iranicus, in contrast to a wider distributional range and high diversity for P. patimari; (iii) suggest that the climatic oscillations of the Pleistocene were associated with the cladogenesis within the P. syrman group; and (iv) allowed for the recognition of conservation units and proposition of management measures.

Spinal Morphometry As A Novel Predictor For Recurrent Lumbar Disc Herniation Requiring Revision Surgery: Results of A Case Control Study.

There is conflicting data on the risk factors for recurrent lumbar disc herniation (rLDH). Most of the predictors for rLDH identified so far are acquired risk factors or radiological factors at the level of the herniation. Whole lumbar spine (WLS) morphometry has not been evaluated as a possible predictor of rLDH. We aimed to evaluate if preoperative spinal morphometry can predict the occurrence of rLDH requiring revision surgery. This retrospective case-control study on 250 patients included 45 patients operated for rLDH, 180 controls without rLDH who had previously undergone microdiscectomy for a single level lumbar disc prolapse, and a holdout validation set of 25 patients. Morphometric variables related to the WLS were recorded in addition to previously identified predictors of rLDH. Logistic regression (LR) analysis was performed to identify independent predictors of rLDH. LR yielded four predictors of which two were WLS morphometric variables. While increasing age and smoking positively predicted rLDH, increasing WLS interfacet distance and WLS dural-sac circumference negatively predicted rLDH. The LR model was statistically significant, χ2 (4) =15.98, P = 0.003, and correctly classified 80.3% of cases. On validation, the model demonstrated a fair accuracy in predicting rLDH (accuracy: 0.80, AUC: 0.70). Larger mean lumbar bony canals and dural sacs protect from the occurrence of symptomatic rLDH. These WLS morphometric variables should be included in future risk stratification algorithms for lumbar disc disease. In addition to the previously recognized risk factors, our study points to an underlying developmental predisposition for rLDH.

MORPHOMETRIC STUDY OF SPLEEN IN CADAVERS OF SOUTH COASTAL REGION

Introduction: The spleen has always been a mysterious organ of seemingly occult function as well as a forbidding organ of extreme vulnerability for the surgeon. But on both fronts, it has yielded considerable ground. The spleen is the largest soft, highly vascularised, lymphatic organ located partially in the epigastrium and mainly in the left hypochondrium. Spleen acts as a lter for blood, storage of lymphocytes and platelets. Old red blood cells are recycled in the spleen. It metabolizes the haemoglobin removed from old senescent RBCs. The knowledge of morphometric variations of spleen helps clinicians, radiologist and surgeons to differentiate it from the various splenic injuries and pathologies The aim of Aims: the study is to nd the morphometric variations of spleen. The present study was done on 68 adult hum Materials and Methods: an spleens of unknown sex. The morphometric features like shape, presence of notches, length, breadth and thickness were noted. Out of 68 spleens Results: studied, ve different shapes of the spleen were observed. 32 spleens were wedge shaped (41%), 20 spleens were triangular shaped (20%), 10 spleens were tetrahedral (12.8%), 16 spleens were oval shaped (20.5%), 0 spleens were irregular shaped (0%). 26 spleens (33.33%) had notches on its superior border, 4 spleens (5.12%) had notches on its inferior border, 32 spleens (41%) had notches both in their superior and inferior borders, 16 spleens (20.51%) were found with absence of notch on either of its borders.The presence of splenic ssure on diaphragmatic surface were noted in 9 (11.53) spleens. The length of the spleen varied between 7cms to 19cms, the breadth of the spleens varied between 4cms to 12cms and the thickness of the spleens varied between 2cms to 8cms The knowledge of morphometric features Conclusion: of the spleen is of great importance to the clinicians, radiologists and surgeons for their surgical procedure

Morphometrical Variations of Tetragonula laeviceps in Different Habitats in Central Sulawesi Province

Background: Habitat is a place for living things to grow and develop. Differences in habitat in an area can affect the size of an organism. This study aims to determine the morphometric variations of Tetragonula laeviceps found in urban and forest habitats in Central Sulawesi Province. Methods: This research was conducted with roaming technique. Morphometric characters observed were 35 characters of stingless bee and analyzed using Microsoft Excel software. Results: The results of this study indicated that the morphometric size variation of T. laeviceps found in forest habitats (3.58 mm) is greater than that of wild bee in urban habitats (3.05 mm). Conclusions: Different habitat characteristics can affect the morphometry variations of the bee, especially in T. laeviceps species. The bee's morphometry body size is greater than in the forest habitat, because in that habitat there are environmental temperatures and types of plant sources of nectar which are more supportive for bee life compared to urban habitats.

Sex dimorphism and evidence of sexually selected traits: A case study on the killifish Aphaniops stoliczkanus (Day, 1872)

AbstractSex dimorphism is found in many organisms and is an important source of intraspecific variation. Among freshwater fishes, all members of the Aphaniidae (killifishes, Cyprinodontiformes) are known for their pronounced sex dimorphism, and it has been proposed that sexual selection has played a role in their diversification. However, few studies have assessed their sex dimorphism in detail. Here, we use Aphaniops stoliczkanus (Day, 1872) to analyse morphological variability within and between sexes and within the total sample using statistical analyses of body morphometry, meristic traits and otolith data. We found that sex dimorphism (i) is significant in many body morphometric variables, but (almost) absent in meristic traits and otolith morphometry, (ii) is most marked in anal‐ and dorsal‐fin lengths (larger in males), and in anal‐ and dorsal‐fin positions (more anteriorly positioned in males) and (iii) does not alter the overall variance of the population unless the character concerned is highly divergent. Our data also suggest that anal‐ and dorsal‐fin lengths in males of A. stoliczkanus are sexually selected traits. Together with literature data, this reinforces the idea that sexual selection plays a role in the diversification of aphaniid species. Our results are also relevant to work on fossils, in which morphological variability is often difficult to interpret.

Sharing the Space: Variation in Morphometric, Ecoregional, Migratory and Reproductive Patterns of Three Sympatric Artibeus Species

Bats of the phyllostomid genus Artibeus are primarily frugivorous, and they often are captured carrying the fruits of figs (Ficus spp.) or Cecropia spp. Although two or three species of Artibeus (sensu stricto) are found sympatrically in many regions of the Neotropics, little is known about the potential competitive interactions of these congeners in areas of sympatry. Competition might occur for food, roost sites, or other resources, and might be expressed as spatial or temporal partitioning in feeding or reproduction, as increased displacement of feeding- or foraging-related characters, or as some combination of these factors. These effects might be more pronounced near the distributional limits of the species, where resources might be more limited (both in abundance and diversity), and more patchily distributed. Three species of Artibeus (A. fimbriatus, A. lituratus, and A. planirostris), are at or near their southern or south-western distributional limits in Paraguay. Previous analyses in Paraguay have determined that A. lituratus and A. planirostris are migratory, with A. lituratus being most abundant during the wet season (October–February), and A. planirostris in the variable season (March–May). Artibeus fimbriatus and A. lituratus are relatively more abundant in the Atlantic Forest ecoregion; and A. planirostris in the Cerrado. In this study we examined morphometric variation in wing and craniomandibular characters, as well as reproductive patterns, to further explore the potential niche partitioning along these dimensions that may reduce competition for resources. We tested for morphometric differences among the species, and for geographic and secondary sexual variation in each of the three species. Both wing and craniodental characters vary significantly among species. Artibeus fimbriatus exhibits sexual dimorphism in only one cranial character, and A. lituratus shows sexual dimorphism in three craniodental characters and in all wing characters, whereas A. planirostris is not sexually dimorphic in any character. Weak geographic variation was found in craniodental characters in A. planirostris, and in wing characters in the other two species. Differences were also encountered in the three species' morphometric responses to temperature and precipitation parameters. Evaluating these differences in morphometric patterns in the context of ecoregional and seasonal associations, migratory status and reproductive patterns, we conclude that the three species mitigate competitive pressure through a complex partitioning of available niche space.

Phenotypic Variations of Aedes aegypti Populations and Egg Abundance According to Environmental Parameters in Two Dengue-Endemic Ecoregions in Paraguay.

Dengue in Paraguay is an endemic disease of public health importance. Several studies suggest that an increased density of Aedes aegypti and the presence of dengue cases may be associated with climatic conditions. This study aimed to establish the phenotypic variations of Ae. aegypti from four cities (Asunción, Itauguá, Minga Guazú, and Ciudad del Este) and the potential association of environmental variables with the number of eggs in capture sites. Eleven morphometric phenotypic characters were evaluated, and environmental data were obtained from Earth Engine and local meteorological stations. An analysis was carried out using principal component analysis and linear discriminant analysis, and we estimated the correlation using [relative humidity, Normalized Difference Vegetation Index (NDVI) and Normalized Difference Water Index (NDWI)] between variables and the number of eggs in each site. Differences in mean NDVI and NDWI between cities and their relationship with the morphometric performance of individuals were also assessed. The study demonstrated morphometric variations between the populations of Ae. aegypti from two ecoregions, with the Litoral ecoregion populations presented a greater phenotypic variation than those observed in the Alto Paraná ecoregion. Significant statistical associations were registered between the number of eggs with relative humidity (r = -0.45) and the NDVI at 100 meters from the capture points (r = -0.61) for Minga Guazú, and with the NDWI at 100 meters (r = 0.54) for Ciudad del Este. Future studies on these Ae. aegypti populations, and its dispersion could contribute to improve vector control measures and foster future genetic studies.

Phylogenetic, Allometric, and Ecological Factors Affecting Morphological Variation in the Scapula and Humerus of Spiny Rats (Rodentia: Echimyidae)

Locomotion, as a fundamental function in mammals directly associated with the use of ecological resources, is expected to have anatomical structures functionally committed that evolved under intense selective pressure, possibly carrying specializations for different locomotor habits. Among caviomorph rodents, the family Echimyidae stands out for having the greatest species richness, with relatively well-resolved phylogenetic relationships, wide variation in body mass, and remarkable diversity of locomotor habits, including arboreal, scansorial, semi-aquatic, semifossorial, and terrestrial forms. Thus, Echimyidae constitutes a promising model for understanding how phylogenetic, allometric, and ecological factors affect the evolution of postcranial structures directly linked to locomotor function. We investigated the influence of these three factors on scapular and humeral morphological variation in 38 echimyid species using two-dimensional geometric morphometry and phylogenetically informed comparative methods. Scapular and humeral shape variation had a low correlation with body mass and structure size, conveying a small or negligible allometric effect. Conversely, a significant moderate to strong phylogenetic signal was detected in both structures, suggesting that an important part of their morphometric variation results from shared evolutionary history. Notably, morphological variation of the scapula was extensively structured by phylogeny, without the marked influence of locomotor habits, suggesting that its shape may be a suitable taxonomic marker. Finally, locomotor habits were important in structuring the morphological variation of the humerus. Our results suggest that the morphologies of the scapula and humerus, despite being anatomically and functionally interconnected, were differentially shaped by ecological factors associated with locomotor habits.

Human kinematic and morphometric sperm subpopulation analysis using CASA technology: A new approach to spermatozoa classification

IntroductionSemen analysis is a clinical method aimed at determining the fertility of a male individual. The traditional subjective method lacks the reliability that can be achieved by computer-assisted sperm analysis (CASA) technology. Unfortunately, this technology has only been used when taking into consideration individually different sperm characteristics. The aim of this work is to present an integrative mathematical approach that considers different seminal variables to establish human sperm subpopulations. MethodsSamples were obtained from thirteen volunteers via masturbation and were analyzed by the routine subjective method and two objective systems, CASA Motility (CASA-Mot) and CASA Morphology (CASA-Morph). ResultsSeminogram variables were reduced to three principal components (PC) showing two subpopulations. Kinematics and morphometric variables each rendered three PCs for four subpopulations. ConclusionsThese results lay the foundations for future studies including different geographical, social, ethnic and age range conditions with the aim of achieving a definitive view of the human semen picture.

Influence of hydrochemical factors on morphometric variability of Scardinius erythrophthalmus in a freshwater river system

Studying fish growth is a complex task because growth depends on many factors. The process of fish growth is influenced by ecological factors of the water environment. Each species of fish has growth characteristics and characteristic changes in this process as a result of the action of natural and anthropogenic factors. We investigated the morphometric features of Scardinius erythrophthalmus in the hydroecosystem conditions of the Horyn River. Fish were caught by amateur fishing methods during 2018–2021 in the section of the hydrographic system of the Horyn River within the Rivne Plateau, which is the northern part of the Volhynian Upland , namely the Horyn River and its tributaries – the Zamchysko River, the Ustia River, and the Stubelka River. The catches included fish aged from 0+ (one-year-olds) to 5+ (five-year-olds). Growth variability was studied for fish aged 1+ to 4+ because their numbers were sufficient for statistical evaluation. We noticed clear features of the morphometric variability of the fish. According to the coefficient of variation for the general populations of S. erythrophthalmus from different rivers, there was mostly significant variability of such growth characteristics as the largest and smallest fish body height, total length, Smith length and short body length of fish. We also noticed the similarity of the morphometric variability of fish of different ages for the Horyn River and Stubelka River and Zamchisko River and Ustia River. The analysis and evaluation of the surface water quality of these rivers was also similar. Thus, Horyn and Stubla districts had a transitional state from II to III quality class, and the Zamchysko River and Ustya River districts had a transitional state from III to IV quality class. We conducted a multivariate regression and it revealed statistical significance and a close correlation between the coefficients of variation of the growth characteristics of fish with the phosphate content in the water (with an average value of the weighting coefficients of 0.50 ± 0.06), nitrite nitrogen (0.39 ± 0.10) and nitrate nitrogen (0.84 ± 0.34). The calculation of the specific growth of fish by full length revealed that the intensity of growth is the highest between the first and second year of life of fish for small rivers (Zamchysko River, Ustya River, Stubelka River) and between the second and third year for the Horyn River. The results presented in the article are valuable and describe the local variation in the morphometric variability of S. erythrophthalmus. This expanded the understanding of the influence of ecological factors of the aquatic environment on the formation of growth characteristics of this species of fish. In the future, our research will continue and study the linear growth of natural fish populations against the background of changes in the ecological and hydrological conditions of the studied region

Establishing a Baseline for Human Cortical Folding Morphological Variables: A Multisite Study.

Differences in the way human cerebral cortices fold have been correlated to health, disease, development, and aging. However, to obtain a deeper understanding of the mechanisms that generate such differences, it is useful to derive one's morphometric variables from the first principles. This study explores one such set of variables that arise naturally from a model for universal self-similar cortical folding that was validated on comparative neuroanatomical data. We aim to establish a baseline for these variables across the human lifespan using a heterogeneous compilation of cross-sectional datasets as the first step to extending the model to incorporate the time evolution of brain morphology. We extracted the morphological features from structural MRI of 3,650 subjects: 3,095 healthy controls (CTL) and 555 patients with Alzheimer's Disease (AD) from 9 datasets, which were harmonized with a straightforward procedure to reduce the uncertainty due to heterogeneous acquisition and processing. The unprecedented possibility of analyzing such a large number of subjects in this framework allowed us to compare CTL and AD subjects' lifespan trajectories, testing if AD is a form of accelerated aging at the brain structural level. After validating this baseline from development to aging, we estimate the variables' uncertainties and show that Alzheimer's Disease is similar to premature aging when measuring global and local degeneration. This new methodology may allow future studies to explore the structural transition between healthy and pathological aging and may be essential to generate data for the cortical folding process simulations.

Leaf Morphometric and Chlorophyll Content Study of Bisbul (<i>Diospyros discolor</i> Willd.) at the Bogor Botanical Garden

Bisbul (Diospyros discolor Willd.) is one of the collections from the Bogor Botanical (BBG). The wide distribution of this plant in Southeast Asia's tropical forests creates many morphometric variations of this species. The diversity of leaf morphometric variations of a plant species can be the basis for grouping various species. This study aimed to determine the morphometric diversity of Bisbul leaves from various locations of origin. The study took samples of bisbul leaves from Bogor Botanical Gardens from three accessions, namely the Philippines, West Java, and Papua. All the trees are over 30 years old. The leaves are taken based on a horizontal position, vertical crown, and leafage. The results showed that the origin of the location gave different multiplier values to calculate the area, namely the Philippines y = 0.733x + 0.034; West Java y = 0.765x-2,949; and Papua y = 0.758x-1.389. The length to leaf width ratio also has differences, namely, the Philippines, which is 2.64, West Java 2.65, and Papua 2.81. The chlorophyll content in young leaves increases in old leaves. The samples from Papua also have the highest chlorophyll content compared to the Philippines and West Java. This difference indicates morphometric variations between the three, even within one species. Some environmental conditions may affect shade areas and tree age. In addition, DNA research from accession D. discolor is also needed to determine the cause of the morphometric variation.

Population genetic structure and morphological diversity of Cruzia tentaculata (Nematoda: Ascaridida), a parasite of marsupials (Didelphinae), along the Atlantic Forest on the eastern coast of South America.

Cruzia tentaculata is a helminth parasite of marsupials and has a wide geographic distribution from Mexico to Argentina. The aim of this study was to analyse the genetic population structure of this nematode along the Atlantic Forest biome. Cruzia tentaculata specimens were recovered from Didelphis aurita, Didelphis albiventris and Philander quica in 9 localities. Morphological and morphometric data were investigated for phenotypic diversity among localities and hosts using multivariate discriminant analysis of principal components. Phylogenetic relationships of C. tentaculata were determined using maximum likelihood and Bayesian inference. The population structure was analysed by fixation indices, molecular variance analysis, Tajima's D and Fu's Fs neutrality tests, Mantel tests and Bayesian clustering analysis. A higher significant morphometric difference for males was observed between localities. In the haplogroup networks, 2 groups were recovered, separating locations from the north and from the south/southeast. The morphometric variation in C. tentaculata between different localities was compatible with this north and southeast/south pattern, suggesting adaptation to different ecological conditions. Population genetic analyses suggested a pattern of evolutionary processes driven by Pleistocene glacial refugia in the northeast and southeast of the Atlantic Forest based on the distribution of genetic diversity.

Morphological and morphometric variations of the water frogs (genus Pelophylax) in Iran

Morphological and morphometric variations of the water frogs (genus Pelophylax) in Iran

Static posturography as a novel measure of the effects of aging on postural control in dogs

Aging is associated with impairment in postural control in humans. While dogs are a powerful model for the study of aging, the associations between age and postural control in this species have not yet been elucidated. The aims of this work were to establish a reliable protocol to measure center of pressure excursions in standing dogs and to determine age-related changes in postural sway. Data were obtained from 40 healthy adult dogs (Group A) and 28 senior dogs (Group B) during seven trials (within one session of data collection) of quiet standing on a pressure sensitive walkway system. Velocity, acceleration, root mean square, 95% ellipse area, range and frequency revolve were recorded as measures of postural sway. In Group A, reliability was assessed with intraclass correlation, and the effect of morphometric variables was evaluated using linear regression. By means of stepwise linear regression we determined that root mean square overall and acceleration in the craniocaudal direction were the best variables able to discriminate between Group A and Group B. The relationship between these two center-of-pressure (COP) measures and the dogs' fractional lifespan was examined in both groups and the role of pain and proprioceptive deficits was evaluated in Group B. All measures except for frequency revolve showed good to excellent reliability. Weight, height and length were correlated with most of the measures. Fractional lifespan impacted postural control in Group B but not Group A. Joint pain and its interaction with proprioceptive deficits influence postural sway especially in the acceleration in the craniocaudal direction, while fractional lifespan was most important in the overall COP displacement. In conclusion, our study found that pressure sensitive walkway systems are a reliable tool to evaluate postural sway in dogs; and that postural sway is affected by morphometric parameters and increases with age and joint pain.

Morphometric analysis of soldier cast of Odontotermes obesus (Rambur) and Microtermes obesi (Holmgren) (Blattodea: Termitidae; Macrotermitinae) from three localities of Potohar region, Pakistan

A great diversity of termite species is found all over the world, among these 53 species are identified from Pakistan. The knowledge about morphological features in soldier cast of termites is proved to be a technical tool for taxonomy and identification. In the present studies, the morphometric variations of external morphology in soldier caste of Odontotermes obesus (Rambur) and Microtermes obesi (Holmgren) from three different areas i.e. Gujar Khan (A), Rawalpindi (B) and Islamabad (C) were studied. About 36 characters like body, thorax, abdomen, from head to mandible tip, head, pronotum, postmentum, mandible, antenna (scape, pedicle, flagellum), and legs parts were used for morphometric measurements. The data were statistically analyzed for significant differences in their mean, standard deviation, standard error, 95% confidence interval, coefficient of variability and analysis of variance. "Student t-test" was used for the comparison of mean values using Minitab version 16. The results of the present study revealed no significant differences among the population samples collected from various localities. However little variations were observed in a few characters like antennal segments (pedicle, scape) and legs (trochanter, tibia) among the soldier cast which are adaptive in nature to survive in the environment. Keywords: Morphometric analysis, soldiers cast, Odontotermes obesus, Microtermes obesi.

Multivariate morphometric differentiation of Macrobrachium species (Crustacea: Palaemonidae) along the northern rivers of Bangladesh

Understanding interspecific morphometric variation is a prerequisite of species identification, evolutionary and taxonomic studies. The external features (i.e. morphometric and ratios) of five Macrobrachium species viz., Macrobrachium rosenbergii, M. lanchesteri, M. dolichodactylus, M. idella and M. lamarrei from three rivers in northern Bangladesh, were used to analyze interspecific morphometric variation. Macrobrachium samples were collected from Jamuneshwari river, Tangon river and Atrai river. Morphometric and ratios data were subjected to univariate ANOVA test. To assess variations among the species, a principal component analysis (PCA) and canonical variate analysis (CVA) were performed. Four PCA explained 95.31% of the variation in morphometric and ratios data. Four CVA were correctly classified as 46.53%, 30.02%, 18.10% and 5.35% respectively using morphometric and ratios data. Morphometric and ratio results from PCA formed a compact cluster among species while in CVA showed that species were completely formed a separate cluster. A dendrogram independently developed based on phenotypic traits among the individuals of the five Macrobrachium species confirmed the presence of phenotypic differentiation. The baseline evidence ensuing from the current study would be advantageous for geometric morphometric, genetic investigations and further in situ conservation of Macrobrachium species in Bangladesh.

Распространение и морфометрические особенности обыкновенной жабы Bufo bufo L. (Bufonidae, Amphibia) на Северо-Востоке европейской части России

The distribution and morphometric features of the common toad (Bufo bufo) in the North-East of European Russia are discussed. The northern boundary of the species' range in the region has a complex configuration. In the west and central part of the region, the toad is found up to latitude 65º42'N and 63º01'N, respectively, the eastern border of its habitat moves northwards up to 64º13' and then drops to the south along the Ural Mountain Ridge. The formation of the modern range of the species in the region was influenced by an extensive network of watercourses and global climate changes. For the last 70 years, toads have distributed along the Pechora River at a distance of more than 600 km. The morphometric variability of the common toad was estimated by 13 linear criteria and 7 indices on the example of four localities in the Komi Republic (Pechora, Beloye Lake, Lokchim Lake, and Sysola Lake). Significant sexual differences were found by most criteria: their values in females are higher than in males. Toads of both sexes inhabiting the eastern and northern localities (Pechora, Lake Beloye) are smaller in size than animals from the southwestern parts of the region (Lokchim Lake, Sysola Lake). Discriminant analysis showed that maximal differences between samples were registered on the body length L., femur length F., tibia length T., head length L.c., and head latitude Lt.c.

Identification of Phalacronotus bleekeri (Günther, 1864) (Siluridae) From the Mekong Delta, Vietnam and Use of Morphological Analysis to Separate Populations

This study identified Phalacronotus to species level and examined its morphometric variation among three collection localities, and between sexes, in the Mekong Delta, Vietnam. Specimens were collected from local markets and fishers, including An Giang (n = 36) and Can Tho (n = 36) in the Hau River and Tien Giang (n = 30) in the Tien River for morphological measurements and DNA barcoding analysis. Eight mitochondrial cytochrome oxidase subunit I (COI) sequences of Phalacronotus sp. shared 99.6 ± 0.23 % similarity with five GenBank (GB) P. bleekeri sequences and differed by 7.6 % to 13.3 % from seven GB P. apogon sequences. The Vietnamese specimens of Phalacronotus were similar to P. bleekeri in number of anal fin rays (75–80) and the shape of the upper jaw teeth. Thus, the COI sequences and these morphological characteristics indicate that Phalacronotus sp. samples collected in the Mekong Delta are Phalacronotus bleekeri (Günther, 1864). Morphometric characteristics differed between populations in 15 of 19 indices (P < 0.05) and between females and males in three characteristics relating to the belly. Head characteristics, body depth, and caudal peduncle depth were the main parameters contributing to the inter-population variation. Based on size-adjusted data, 96.7 % of specimens were correctly classified from the Tien Giang population, while 27.8 % and 33.3 % were misclassified between the Can Tho and An Giang populations, respectively. These results indicate that morphometric parameters of P. bleekeri varied mainly between populations in the two Mekong River tributaries.