جستجوی مقالات مرتبط با کلیدواژه « لندمارک » در نشریات گروه « زیست شناسی »

This study was conducted to investigate the sexual dimorphism of Cyprinion macrostomum in the Little Zab River using traditional and geometric morphometric methods. For this purpose, during 2021, 37 specimens (21 females and 16 males) were collected using an electrofishing device. After determining the sex of the collected specimens, 18 morphometric characteristics were measured using a digital caliper. Also, to extract body shape data in geometric method, photographs were taken from the left sides of both males and females. Then, 16 landmark-points were digitized in tpsDig2 software. The extracted data were analyzed using multivariate statistical analysis including principal component analysis (PCA), T.tests and Mann-Whitney.The results of discriminant function analysis (DFA) and T-test of the body shape showed a significant difference between males and females (P<0.05). The males have more body depth, posterior snout, and shorter caudal peduncle length than the females. Males and females had significant differences in 8 morphometric traits (P<0.05). The results of the  present study confirmed the performance of traditional and geometric morphometric methods in the differentiation of the C. macrostomum sexes.

The honey bee is one of the most important and economic species of insects due to its important role in the pollination of agricultural and non-agricultural plants and the products it produces directly. The western honey bee Apis mellifera, which is now considered a cosmopolitan species due to its widespread distribution by humans, originated in Africa, Europe, and West Asia. In order to evaluate the diversity of this bee in parts of the northwest of the country, worker bees were collected from 6 study stations in West Azerbaijan and East Azerbaijan provinces and evaluated using the geometric morphometric method. Changes in the size and shape of the forewing and hindwings were investigated using 16 homologous landmarks at the bifurcation of the wings. In terms of the size of the fore and hindwings, the Chahar Borj population of West Azerbaijan had the largest and the Malekan population of East Azerbaijan had the smallest fore and hindwings, and populations of all the study stations of East Azerbaijan had significant differences with West Azerbaijan. In terms of the shape of the forewing, all pairwise compared populations except for the population of Sahand mountain and Kordeh Deh village had significant differences, but in the hindwing, this difference was seen only in three pairwise comparisons. In addition, the regression analysis showed that, unlike the hindwing, changes in the wing size and wing shape in the forewing are dependent on each other, and allometry is also seen. This study showed that despite the proximity of the study stations to each other, diversity is observed in the bee populations.

The aim of this study was to determine the variations among cephalic plates of individuals in two populations of Clinopodes flavidus in Alborz Mountains, by means of landmark-based techniques of geometric morphometrics. Therefore, 17 landmarks and semi-landmarks on the coxosternite of poison claw and seven landmarks and semi-landmarks on the tarsangulum of poison claw were selected using TpsDig2 software. Data of landmarks, after procrust analysis, were subjected to various multivariate analyses, such as Principle Component Analysis (PCA) and Canonical Variate Analysis (CVA) by means of PAST and MorphoJ softwares. The results obtained demonstrated that shape variations in coxosternite were significantly different among various populations (p<0.001). This study revealed the usefulness of landmark-based geometric morphometrics in the differentiation of various populations of Clinopodes flavidus in Alborz Mountains.

This study was conducted to understand the morphological variation of four populations of Schizothorax pelzami from Iranian inland waters. For this purpose, a total of 81 specimens were collected from the Bidvaz, Cheshmeh-Ali, Kalat and Aal rivers. After anesthesia, all specimens were fixed into buffered formalin and transferred to the laboratory. Then, the left sides of all individuals were photographed. To extract the body shape data, 14 landmarks-points were defined and digitized on 2D image using TpsDig2 software. To eliminate size, direction and position from data, the Generalized Procrustes Analysis (GPA) was performed. Then, PCA, MANOVA/CVA and cluster analysis were used for further investigation. The results showed that there was no significant difference but some overlapping among the studied populations on the basis of PCA analysis was observed. The CVA graph separated the studied populations from on another. The main differences in body shape of the studied populations were related to the position of the snout, the depth of head and body, and the length of caudal peduncle. The observed changes can be considered to be an adaptation to their habitat, which has been influenced by different environmental parameters.

For geometric morphometric comparison of chub, Squalius turcicus,, in Ghezel-Ozan, Kasma, Palangabrud, Talvar, Tonekabon, Chalakrud, Divandareh, Zalkie, Zarinrud, Sefiedrud and Shafarud and Noor rivers of south-western Caspian Sea basin, 243 specimens were captured by a seine nets. After anesthetizing in 1% clove oil solution and fixing in 10% neutralzed formalin, specimens were transferred to the Isfahan University of Technology Ichthyology Museum (IUT-IM) for further studies. To study the variation of body shape based on geometric morphometric methods, 13 landmarks were defined on the two-dimensional images taken from the left side of samples using the TpsDig2 software. After Procrustes analysis (GPA), digitized data were analyzed using multivariate analyses such as principal component analysis (PCA), canonical correlation analysis (CVA) and cluster analysis, also, network deformation changing configuration patterns of population compared to form of the consensus by visualization. Results showed significant differences between the populations studied. The major differences in body shape of the studied populations were related to the head and body depth, and position of the pectoral, anal and dorsal fins. The observed changes are due to adaptation to the habitat, which has been influenced by different habitat conditions and has shown different body shapes.

The aim of this study was to identify the morphological parameters effective insexual dimorphism in Gambusia holbrooki, as a model but invasive livebearer species in Iranian inland waters, using landmark morphometric truss network system. The linear discriminant analysis showed an average percentage of specimens classified of 100% for morphometric characters indicating a high rate of correct classification of individuals into their original populations. The significant differences between two sexes were observed in the head length, head width, body depth, pre-dorsal length, pre-ventral length, pre-anal length, fork length, dorsal fin length, anal fin length, caudal-peduncle depth and caudal-peduncle length.

. In this study, morphological variation of three species of Squalius in Iranian basins was studied. For this purpose, 709 specimens were captured from the Caspian Sea, the Urmia Lake, the Namak Lake and the Tigris basin. After anesthetizing in clove oil solution and fixing in 10% neutralized formalin, specimens were transferred to the Isfahan University of Technology Ichthyology Museum (IUT-IM) for further studies. In the laboratory, some 14 meristic characters were counted under a streomicroscope. Also, images were analyzed with ImageJ software and 19 morphometric characteristics were measured. In addition, 13 landmarks were defined and digitized on images taken in tpsDig2 software in order to extract geometric morphometric data. Kolmogorov-Smirnov, Kruskal-Wallis, ANOVA, Duncan test, PCA, CVA and cluster analysis methods were used to analyze the differences among the populations. The results of PCA and CVA meristic and morphometric analyses showed no significant differences among the studied populations. The populations of the species studied were significantly different in 11 meristic and 15 morphometric characteristics. Also, the major differences observed in the results of geometric morphometric analysis were related to the position of the pectoral fin, body and head depth. In general, the studied populations highly overlapped, and we suggest that the populations of genus Squalius should be further studied by molecular methods.

The sexual dimorphism is one of the most subjects for biologists that create using natural selection on individual based on mating system, the ecological differences between individual and the pressure of natural selection on reproductive associated traits. The aim of this study is evaluate of sexual dimorphism in Ponticola cyrius in Tajan River using geometric-morphometric and traditional morphometric methods. So, 40 ponticola cyrius (male= 20 and female=20) were caught from Tajan River. Then, 31 absolute morphometric characterizes measured and also 27 relative morphometric characterizes calculated. For comparison of geometric-morphometric was provided the images from left side- view, dorsal and abdominal views. In order to extract data from the body shape the 20, 19 and 12 landmarks determined in the side, abdominal and dorsal view, respectively, and then digitalized by tpsDig2 software on 2D pictures. Then, the obtained data was analyzed by procrustes methods. The obtained results from using geometric-morphometric and traditional morphometric analysis were evaluated using Principal component analysis, Discriminant function analysis and T tests. The results indicated a significant difference between female and male in all of the mentioned views. According to our results, the male of ponticola cyius has more length, body width, head height, length of dorsal fin base and anus than female ones. In addition, the color of male fish was darker than female and sexual papilla in male is more keen and length than female. The results of traditional and geometric morphometric studies largely confirmed each other.

Garra rufa is one of the 73 Garra species of the family Cyprinidae. Scales are used more commonly than any other structure in population dynamic studies, because of their transparency, ease of sampling, and the minimal in-juries caused to the fish during their removal. To discriminate fish from different rivers including Bashar, Behbahan, Gerdab, Kheirabad, Kooshk-e-Bahram, Mazoo, Palangan, Sendegan, Shoor-Abad, and Sirvan Rivers using geometric morphometric analyses of the scale shape, landmark based geometric morphometrics method was used. Seven landmark points were depicted on each scale using the software TpsDig2. After procrustes analyses, landmark data were exposed to principle component analysis (PCA), CVA, and cluster analyses using the past software. The results showed that th-ere were significant scale shape differences among some populations, but most of the samples showed overlapping sh-ape distribution and could not be separated robustly. Among the samples which were analyzed, only the Sendegan and Gerdab river samples did not show significant difference in scale shape compared to all other samples.