جستجوی مقالات مرتبط با کلیدواژه « دوشکلی جنسی » 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.

Scorpions are a group belonging to the Phylum Arthropoda. They are found under stones and heavy things. Some researchers studied the scorpions of Iran. In the present investigation specimens of Hemiscorpius enischnochela were collected from Manoojan, South of Kerman Province. We used crowers bar and wood to move the stones and heavy tings. To obtain the samples, tongs and forceps were used. Scorpions were gathered from different areas of Manoojan, South of Kerman Province in different seasons. To identify and study morphological characters of specimens, the stereo –microscope Olympus Lica 2000 was used. In the present investigation different external morphological characters of males and females of H. enischnochela were studied. It indicated that there are some sexual dimorphism, between males and females in the mentioned species as follow: A- The length of body in male is longer than of that in female. B- In male mesosoma is longer than of that in female. C- In male metasoma length is longer than of that in female. D- In female pedipalp slightly less slender than in male. E- In male femur length is longer than of that in female. F- In male length of movable finger is more than length of moveable finger female. G- In female chela is more bulky than in male. H- In male poison sac length is more than length in male. I- In male, pectin length is more than pectin length in female. K- Male pectin has 16 teeth (in each pectin), female pectin has 8-9 teeth. J- In female genital operculum composed of a hexagonal plate, divided by a longitudinal furrow, in male genital operculum composed of two ovoid plates. Based on this study there is a distinct degree of sexual dimorphism in the Hemiscorpius enischnochela.

In animals, Sexual dimorphism can be based on morphological characteristics or measurable characteristics. In scorpion, except a few species that have two sexual forms, there is no significant difference between males and females. In this study, 12 measurable characteristics of male and female Hottentotta saulcyi, from the Rudbar area located on the border of Lorestan, Isfahan and Chaharmahal and Bakhtiari provinces, were measured and analyzed by SPSS 16 software. Independent Sample T-test showed a significant difference between the three traits, the distance between the two shoulder lines, shoulder length, and the number of shoulder teeth between males and females. The result showed that in male, the length of the shoulder is significantly larger and also the number of shoulder teeth more than female, but the distance between the two shoulder strains in the material is larger than the male, and therefore, these traits can be in the diagnosis of both males and females.

The males and females of Colorado beetles do not reveal clear dimorphism and therefore they have high resemblance so that recognition of the sexes by simple eye is too difficult. In order to study sexual dimorphism in Colorado beetle، three geographical populations were collected from potato fields in Ardabil، Bahar and Hamedan regions by manual method and direct observation in the summer of 2012. Fore and hind wings were separated and 7 and 8 landmarks were orderly selected for the fore and hind wings at the end and angle of veins. Geometric coordinate of landmarks were converted to shape and size variables as comparison factors between the sexes. Wings relative variations were determined separately in male and female and it revealed variations of wing shape in evolutionary process. Multivariate analysis based on the results of regression of shape variables showed fore wing had allometry and hind wing had not allometry. Two way MANOVA analysis was conducted for observation of shape differences (base on average of shape variables) and size differences. The analysis showed that there were significant differences in shape of fore wing between the sexes.