Determination of suitable sex for morphological comparison in populations of Aphanius dispar using geometric morphometrics

Sexual dimorphism is a phenomenon among some fish species such as the members of the genus Aphanius. Among species with sexual dimorphism, morphological analysis needs to be performed separately. Hence, this investigation was carried out to determine suitable sex of Aphanius dispar for morphological studies. A total 180 specimens (male and female) were collected from populations of Sarbaz, Mehran and Shour rivers. Digital picture of speciments were taken from their left sides and then 17 landmark points cover their body shape were determined and digitized using tpsDig2 software. The data after GPA, were analyzed using PCA, CVA and MANOVA. The results revealed that studied population can be differitiated based on their body shap but between male and female of the Shour and Mehran rivers did not found significant different ib their separate analysis. Sexual dimorphism in the head and trunk seems to be a general feature in A. dispar. Based on the results in A. dispar, males can be suggested as proper sex for morphometric studies

Allometric growth pattern and morphological changes of green terror Andinoacara rivulatus (Günther, 1860) (Cichlidae) during early development: Comparison of geometric morphometric and traditional methods

Allometric growth pattern and body shape changes of the Green terror (Andinoacara rivulatus) (Cichlidae) were studied using landmark-based geometric morphometric (GM) and traditional methods, from hatching up to 1266 Hours Post Hatching (HPH) under culture conditions. The left side of specimens were photographed using digital camera and morphometric characters, including total length, head length, tail length, trunk length, eye diameter, snout length and body depth were measured using ImageJ software. In GM method, ten landmark-points were digitized on 2D pictures. Allometric growth patterns were calculated as a power function of total length and described by the growth coefficient to reveal important steps in the species’ early life history. The scores of relative warp analysis (RW) were used as descriptors for the variation in shape. The growth patterns obtained by both traditional morphometric (TM) and GM methods showed similar patterns, but GM showed effective results to interpret the morphological changes and revealing larval stages based on the body shape change. The results also showed higher growth rate of head and tail regions up to yolk sac absorption following by isometric patterns, after begin of exogenous feeding. Based on the findings, the early development of this species can be divided into five stages based on its morphology, including newly hatching larvae (up to 48 HPH), younger larvae (156 HPH), older larvae (426 HPH), younger juvenile (666 HPH) and juveniles. The results confirmed this fact that morphological development and growth patterns during early life stages in A. rivulatus closely match its immediate required function

Habitat suitability index of Barbus cyri (Heckel, 1843) in Tootkabon River, the South Caspian Sea basin, Iran

Knowledge of habitat requirements of aquatic animals plays an important role in fisheries and protection programs of aquatic ecosystems. Hence, this study was conducted to investigate the suitability indexes of habitat use and habitat suitability index (HSI) of Barbus cyri in its distribution range in Tootkabon River. A number of environmental variables, including elevation, water depth, river width, river slope, velocity, substrate type, and average diameter of bed stone, riparian vegetation type and the relative abundance of B. cyri at 13 stations and three replications from the downstream to upstream were examined during November 2013. The results showed that B. cyri mostly selects upper stretches of the river with higher velocity, middle depth, lower width and bed rock substrate i.e.bed with boulder cover and grasslands and also its residential area is of riparian type compared with the available ranges. Habitat selectivity index for B. cyri showed that the elevation is 130-220 m, water depth 18-75 cm, channel width less than 12 m, channel slope 0.5-2.3%, water velocity less than 0.8 m.s-1, bed rock substrate, average diameter of bed stone larger 15-50cm. Presence of these conditions with HSI of 0.798 indicates that Tootkabon River is an excellent habitat for B. cyri

The determinant factors underlying habitat selectivity and preference for Black fish Capoeta capoeta gracilis (Keyserling 1891) in Siyahrud River (a tributary of Sefidrud River basin)

Understanding habitat requirements of aquatic organisms is key factor for sustainable exploitation and biodiversity conservation of riverine ecosystems. The habitat preference in fish has extremely important for the management of fish populations. The habitat requirements of Black fish (Capoeta capoeta gracilis) in Siyahrud River -tributaries of the Sefidrud River in Caspian basin- were studied in 13 stations along the river during October to November 2013. Hydrological characteristics of the river including water velocity, depth and width, slope, altitude, type of substrate materials, and plant coverage were recorded for each station. Ranges of habitat use and habitat selectivity with regard to the availability of habitat units for different variables were measured using HABSEL software. Despite significant correlation between the water velocity and depth, results from multiple regressions showed preference for the depth range of 17 to 38 cm. The results showed that behavioral preference in C. capoeta gracilis for the velocity was between 0.44 and 0.56 m/s. Also, specimens tended to be present in cobble stone substrate. Therefore, the anthropogenic activities over the Siyahrod River changing the river width, depth, substrate and the flow rate may affect the presence and distribution of C. capoeta gracilis in the mentioned river

The determinant factors underlying habitat selectivity and preference for Black fish Capoeta capoeta gracilis (Keyserling 1891) in Siyahrud River (a tributary of Sefidrud River basin)

Understanding habitat requirements of aquatic organisms is key factor for sustainable exploitation and biodiversity conservation of riverine ecosystems. The habitat preference in fish has extremely important for the management of fish populations. The habitat requirements of Black fish (Capoeta capoeta gracilis) in Siyahrud River -tributaries of the Sefidrud River in Caspian basin- were studied in 13 stations along the river during October to November 2013. Hydrological characteristics of the river including water velocity, depth and width, slope, altitude, type of substrate materials, and plant coverage were recorded for each station. Ranges of habitat use and habitat selectivity with regard to the availability of habitat units for different variables were measured using HABSEL software. Despite significant correlation between the water velocity and depth, results from multiple regressions showed preference for the depth range of 17 to 38 cm. The results showed that behavioral preference in C. capoeta gracilis for the velocity was between 0.44 and 0.56 m/s. Also, specimens tended to be present in cobble stone substrate. Therefore, the anthropogenic activities over the Siyahrod River changing the river width, depth, substrate and the flow rate may affect the presence and distribution of C. capoeta gracilis in the mentioned river

Osteological development of the vertebral column, paired, dorsal and anal fins in Rutilus caspicus, Pravdin (1927) (Teleostei: Cyprinidae)

Study of the osteological development in fishes is important in fisheries, biology and aquaculture. It can be used as an early bio-indicator of non-optimal rearing conditions. The Caspian roach, Rutilus caspicus is a native cyprinid fish of the Caspian Sea basin that its artificial propagation is fulfilled in hatcheries to recruit its natural stocks. Hence, this study was conducted to provide early development of its vertebral column, paired and median fins from hatching up to 90-dph as basic biological information. For osteological examinations, the specimens were cleared and stained and a detailed description of the ontogeny of the post-cranial skeleton provided. The results showed that no osteological structure was present at hatching. The first observed skeletal structure was the vertebral column followed by the pectoral fins, caudal fins and almost simultaneously dorsal, anal and pelvic fins

Geometrics morphometric comparison of populations of Waspi Cabdio morar (Hamilton, 1822) in Mashkil and Mokran Basins

Landmark based geometric morphometrics and comparison of meristic characters was used to understand potential differences between populations of Waspi in Mashkil and Mokran Basins. 97 specimens of Waspies were caught (64 from Mashkil River and 33 from Sarbaz River). 14 landmarks were digitized on pictures taken from left side of specimens and meristic characters were counted. Data were analyzed using PCA and DFA after procrustes superimposition and data standardization. There are some meaningful shape differences between populations (P<0.001). The body and caudal peduncle in Sarbaz fishes where higher than that of Mashkil fishes, but the peduncle in Mashkil River was longer than Sarbaz fishes. Considering to no meaningful differences between the two populations in meristic characteristics and Due to different conditions in the rivers (vegetation density, water depth, water flow and food availably), the observed differences in shape of fishes could be considered as phenotype plasticity to the conditions of the rivers

Description of the ovarian follicle maturation of the migratory adult female Bulatmai barbel (Luciobarbus capito, Güldenstädt 1772) in captivity

The study aimed to investigate the maturation process of ovarian follicles and ovary structure of migratory form of female Bulatmai barbel (Lucioarbus capito). The histology of oogenesis coincided with that known from most teleosts. The ovarian structure was found to be cytovarian. The development of the oocytes is started from early May along with spawning and the degeneration of matured oocytes. The oocytes’ development continues during summer and early fall and the ovary undergoes a dormant period in fall and winter. In the next spring, the next phase of oocyte development started along with the rising of water-temperature. During May and June the development of the oocytes is completed and the final maturation can occur if the environmental conditions are suitable. The Gonadosomatic Index values show a concordance with the oocyts maturation in the ovaries. The reproductive strategy, with long spawning periods during spawning season, found to be batch spawner with asynchronous oogenesis pattern. The results show that it can be matured while captivity

A comparative study of alive and dead eleutheroembryo of Beluga (Huso huso) shape (5DPH) using geometric morphometric method

High mortality of beluga prelarvae (Huso huso) occurs in hatcheries and this appears to be linked to various abnormalities. Hence, this study was conducted to compare the body shape of alive and dead beluga prelarvae (5DPH) and to find the patterns of deformities among losses using geometric morphometric method. This method was applied to extract shape data as landmark’s Cartesian coordinates. Specimens were photographed using digital camera and the landmarks put on two-dimensional images using tpsDig2. Landmark data after GPA (Generalized Procrustes Analysis) analyzed using PCA and DFA. Results showed significant differences between alive and dead prelarvae shapes. In addition, various pattern of deformities found in the operculum, yolk sac and caudal peduncle parts. Future studies are suggested on larvae and juvenile stage

A comparative study on body shape of the genus Alburnus (Rafinesque, 1820) in Iran, using geometric morphometric analysis

Geometric morphometric method was used to examine body shape variations among all the seven valid species of the genus Alburnus in Iran. In total 409 specimens of A. chalcoides, A. filippii, A. atropatenae, A. caeruleus, A. mossulensis, A. hohenackeri and A. zagrosensis were collected from Babolrud, Baleqlu-Chai, Miriseh, Sarabeleh, Gamasiyab, Mahabad-Chai Rivers and the Gandoman lagoon, respectively. Shape data was extracted by recording 15 landmark points on 2-D pictures of specimens. The PCA, DFA and CVA/MANOVA analysis were used to examine shape differences among the seven species. Significant differences were found among the species in term of body shape. The PCA and CVA/MANOVA showed separation of A. hohenackeri and A. caeruleus from the others. Results revealed that the studied species are divided into two categories; a group with great body depth and short caudal peduncle and the other one with shallow body depth and longer caudal peduncle. The obtained body shape properties can provide a shape-based identification key for the genus Alburnus in Iran, useful for fisheries and stock management or conservation programs