275 research outputs found

    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)

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    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

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

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    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)

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    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

    Occurrence and intensity of parasites in Prussian carp, Carassius gibelio from Anzali wetland, southwest Caspian Sea

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    The aim of this study was to detect the occurrence of parasites in Prussian carp, Carassius gibelio as the most important alien fish in Anzali international wetland. This undesirable fish was introduced accidentally to Iran with Chinese carp fries which imported to the country during the last decades and then acceded to Anzali wetland. Today this fish has significant stocks in Anzali wetland but there have been limited studies about the parasites of this fish in Anzali wetland. During this study a total of 90 Prussian carp were collected by electrofishing and gillnets from April through July 2012. After recording biometric characteristics, common necropsy and parasitology methods were used. A total of 2715 individuals out of 11 parasite species were recovered. Parasitofauna consisted of: two protozoans, Ichthyophthirius multifiliis and Trichodina sp.; one nematode, Raphidascaris acus; one trematode, Diplostomum spathaceum; six monogeneans, Dactylogyrus formosus, Dactylogyrus dulkeiti, Dactylogyrus baueri, Dactylogyrus arquatus, Dactylogyrus inexpectatus and Gyrodactylus kobayashii; and one crustacean, copepodid stage of Lernaea cyprinacea. The monogeneans had the highest prevalence values (88.89%). The occurrence of D. inexpectatus in C. gibelio is reported for the first time in Iran

    Effects of LHRH-A2 and chlorpromazine (dopamine antagonists) on inducing spawning in Caspian Kutum, Rutilus frisii kutum, from the southwest of the Caspian Sea

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    Caspian kutum, Rutilus frisii kutum, is one of the most commercially important fish species in the Caspian Sea, but there are few reports about the endocrinology of induced spawning in this fish. In the present study, 54 individuals of female broodstocks of Kutum were studied for quantity and quality of propagation index, during March and April 2007. Hormone treatments include: LHRH-A2 (1 µg kg-1bw;chlorpromazine (2.5 mg kg-1bw); LHRH-A2 + chlorpromazine (1µg kg-1bw+2.5 mg kg-1bw); CPE as a positive control (1 mg kg-1bw); Physiological saline as a negative control; and normal brood stocks without injection. For histological examinations, ovarian samples of non-ovulated females were fixed in bouin's fluid. The routine procedures of preparation of tissues were followed and the paraffin blocks were cut at 5-7 microns, stained with H&E and studied under light microscope. The results showed that the highest percentage of ovulated females belonged to group 1 without significant difference with positive control.There was a significant difference between ovulated females in the LHRH-A2, chlorpromazine and LHRH-A2 + chlorpromazine treatments (P0.05). Chlorpromazine could not be a potent dopamine antagonist and the microscopic observations of ovary in non- ovulated brood stocks showed that the oocytes in these treatments were in the final phase of IV stage

    An investigation on digestive parasites of fishes in Boojagh Wetland, north Iran

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    Digestive parasites of commercial fish species in the Boojagh wetland were studied in 2002. The fish species included Esox lucius, Cyprinus carpio, Blicca bjoerkna, Tinca tinca, Carassius auratus, Rutilus frisii kutum, Rutilus rutilus and Scardinius erythrophtalmus. Species C. auratus, R. frisii kutum and B. bjoerkna were found free of digestive parasites. The other five species were carrying one of the three digestive parasites Raphidascaris aces, Caryophyllaeus fimbericeps and Asymphylodora tincae. R.acus parasite was isolated from E. lucius and E. erythrophtalmus infecting the species with a mean intensity of 1.1± 11.15 and 1.8±0.83, a prevalence of 15.4% and 20.2% and a mean abundance of 1.69 and 0.38 respectively. C. carpio and R. rutilus were only infected with C. fimbericeps parasite with a mean intensity of 30.30±46.33 and 5±0, a prevalence of 46.5% and 2.78%, and a mean abundance of 15.48 and 0.14 respectively. The parasite A. tincae was observed only in T. tinca infesting the fish with a mean intensity of 20±0, a prevalence of 25% and mean abundance of 5. Infection of Esox lucius with the parasite A. tincae had been reported from other sites, but this is the first record of Scardinius erythrophtalmus being infected with the parasite. This is also the case for infection of C. carpio with the parasite Caryophyllaeus fimbericeps which was reported before, but found infesting R. rutilus in the Boojagh wetland for the first time

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

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    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

    Parasites of some bonyfish species from the Boojagh wetland in the southwest shores of the Caspian Sea

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    The Boojagh international wetland with a surface area of 80 hectares and 25 fish species is located in the southwest shores of the Caspian Sea (Guilan province, Iran), but there is no report about fish parasites in this wetland. In the present study, a total of 553 individuals of 8 fish species including Cyprinus carpio (n=71), Abramis bjoerkna (n=153), Carassius auratus gibelio (n=89), Esox lucius (n=39), Rutilus rutilus caspius (n=36), Rutilus frisii kutum (n=81), Scardinius erythrophthalmus (n=119) and Tinca tinca (n=4), were collected in October 2001 through November 2003. Eight parasite species were identified in the fishes consisting of 1 nematode: Raphidascaris acus (in E. lucius and S. erythrophthalmus); 1 cestode: Caryophyllaeus fimbriceps (in R. rutilus caspius and C. carpio); 2 digenean trematodes: Asymphylodora tincae (in T. tinca) and Diplostomum spathaceum (in all of the fish species except for T. tinca and S. erythrophthalmus); 2 monogenean trematodes:Tetraonchus monenteron (in E. lucius) and Dactylogyrus sp. (in C. carpio, A. bjoerkna and C. auratus gibelio); 1 crustacean: Lernaea cyprinacea (in A. bjoerkna, T. tinca and R. rutilus caspius) and 1 leech : Piscicola sp. (in R. rutilus caspius and C. carpio). The occurrence of R. acus in S. erythrophthalmus and also that of C. fimbriceps in R. rutilus caspius are reported for the first time as new host records

    Effect of Surgical Flap on IL-1β and TGF-β Concentrations in the Gingival Crevicular Fluid of Patients with Moderate to Severe Chronic Periodontitis

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    Background: Growth factors play a major part in wound healing in many tissues including the periodontium. Transforming growth factor-β1 (TGF-β1) is one of these factors present in the gingival crevicular fluid. In addition, it is considered as one of the most important anti-inflammatory cytokines. Interleukin-1β is a proinflammatory cytokine that presents itself in gingival inflammation and the GCF. Such factors might be of value as prognostic markers of wound healing activity and the therapeutic progress following flap surgery. Objective: The aim of this study was to evaluate the effect of surgical flap on the concentration of IL-1β and TGF-β in the GCF of patients with moderate to severe chronic periodontitis. Methods: The GCF samples were collected, using the Perio-Paper strip at phase 1 (pre-surgery), phase 2 (4th week post surgery) and phase 3 (12th week post surgery) from 20 sites of 10 patients undergoing flap surgery. After the elution, IL-1β and TGF-β concentrations were measured by enzyme-linked immunosorbent assay (ELISA). Results: The mean TGF-β and IL-1β concentration decreased from phase 1 to phase 3 (p<0.05). There were no significant statistical correlations between IL-1β and TGF-β1 concentrations in the 3 assessment phases. There was a significant statistical correlation between TGF-β1 concentrations and the Plaque Index (PI) in phase 2 (p<0.05). There was a significant statistical correlation (p<0.05) between IL-1β and TGF-β1 concentration and the probing pocket depth (PPD). Conclusion: The flap surgery has a significant effect on decreasing IL-1β concentration. In the case of TGF-β1, probably the decrease in the concentration after treatment might be due to the removal of the inflammatory stimulants

    Bright off-axis directional emission with plasmonic corrugations

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    In this work, a new plasmonic bulls-eye structure is introduced to efficiently harvest the emitted light from diamond nitrogen vacancy (NV) centers. We show that the presence of a simple metal sub-layer underneath of a conventional bulls-eye antenna, separated by a dielectric layer, results in the spontaneous emission enhancement and increment in out-coupled light intensity. High Purcell factor is accessible in such a structure, which consequently boosts efficiency of the radiated light intensity from the structure. The structure shows considerable enhancement in far-field intensity, about three times higher than that of a one-side corrugated (conventional) optimized structure. In addition, we study for the first time asymmetric structures to steer emitted beams in two-axis. Our results show that spatial off-axial steering over a cone is approachable by introducing optimal asymmetries to grooves and ridges of the structure. The steered light retains a level of intensity even higher than conventional symmetric structures. A high value of directivity of 16 for off-axis steering is reported. © 2017 Optical Society of America
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