Paraschistura ilamensis, a new species of loach from the Tigris River drainage (Teleostei: Nemacheilidae)

Paraschistura ilamensis, new species, is described from the Tigris River drainage, Iran. It is distinguished from other species of Paraschistura in Iran by a combination of the following characters: emarginate caudal fin, stout, deep and scaled body, deep caudal peduncle, 7-10 irregular and interrupted vertical pale brown bars on flanks, two obvious dark spots on the upper and lower caudal fin unbranched rays, and moveable protuberance at the antero-ventral corner of the eye in males

Descriptive osteology of Squalius orientalis from Urmia Lake basin of Iran

Osteological features are important to study the taxonomy and phylogenetic relationship of fishes. Since there is no information is available about osteological features of Squalius orientalis, therefore this study was aimed to provide a detailed description of the osteological features of this species from the Urmia lake basin of Iran and comparing it with population of S. orientalis from the Caspian Sea basin. For this purpose, the specimens were collected from Zarineh River of the Urmia lake basin and cleared and stained with alizarin red S and alcian blue for osteological examinations. Finally, a detailed osteological features of this species was provided and compared with those of the Caspian Sea basin. Based on the results, having a longer pre-vomer, dorsally oriented parasphenoid alar, longer ventral blade-shaped process of the orbitosphenoid, concaved masticatory plate, pointed ascending process of the palatine, concaved posterior margin of the opercle, and a small posterior process of the cleithrum can differentiate S. orientalis of the Urmia Lake basin from those of the Caspian Sea basin. In addition, the observed osteological difference suggest that both studied populations belong to same taxon

Morphological variability of the Aspius aspius taeniatus (Eichwald, 1831) in the Southern Caspian Sea Basin

Traditional morphometric measurements and meristic counts were used to investigate the hypothesis of population fragmentation of Mash mahi, Aspius aspius taeniatus (Eichwald, 1831) among two fishing areas in southern Caspian Sea basin (Tonekabon:32 specimens and Sari:34 specimens ). Univariate analysis of variance showed significant differences between the means of the two groups for 12 out of 26 standardized morphometric measurement and three out of nine meristic counts. In discriminant function analysis (DFA), the proportion of individuals correctly classified into their original groups was 82.1% and 61.2% for morphometric and meristic characteristics, respectively. Clustering based on Euclidean distances among groups of centroids using an UPGMA and also principal component analysis’ results (PCA) for morphometric and meristic data indicated that two samples of Mash mahi were distinct from each other in these regions, while there were a relatively high degree of overlap between two locations

Hemiculter leucisculus (Basilewsky, 1855) and Alburnus caeruleus Heckel, 1843: New data on their distributions in Iran

This paper provides information on the geographic distributions of two cyprinid species: Hemiculter leucisculus (Basilewsky, 1855) and Alburnus caeruleus Heckel, 1843, in the world and the entire drainage systems in Iran. The new distribution records were taken from Maroon River (Jarrahi River system) and Chardaval River (Karkheh river system), both in Tigris River basin showing wide and narrow distribution ranges of these two cyprinid fishes, respectively. The main introduction sites and distribution range of H. leucisculus is the southern parts of the Caspian Sea basin in Iran from where it has probably been translocated to other Iranian basins along with exotic Chinese carps. Although A. caeruleus is native to Tigris River basin, it had been already recorded only from Gamasiab and Doab rivers in 2009 in Karkheh River system (Tigris) and thus the present study extends its distribution range. In case of alien species, human-mediated fish introductions may increase faunal similarity among primary drainages due to a strong tendency for taxonomic homogenization caused primarily by the widespread introduction of cyprinid fishes. Fish faunal homogenization might be highest in drainages (e.g. Caspian Sea and Tigris basins) subjected to the greatest degree of disturbance associated with human settlement, infrastructure and change in land use. The provided data might be used in conservation program of freshwater fishes of Iran

First record of the loach fish Paracobitis cf. malapterura in the Kavir basin, northern Iran

The loach fish Paracobitis cf. malapterura Valenciennes, 1846 (Nemacheilidae), formerly believed to be an endemic species in the Caspian Sea basin, was recorded for the first time in the upper Kavir basin. This extension of its recorded range makes it likely that it has been overlooked in other parts of the Kavir basin

Effect of Curing Time on Polymerization Rate of Bulk-Fill Composite Resins

Objectives: The aim of this study was to compare polymerization depth of two bulk-fill and one conventional composite cured for different times.Methods: This in vitro experimental study was conducted on 54 composite samples (2×4×10mm) fabricated of Tetric N-Ceram bulk-fill, x-tra fil bulk-fill, and Grandio conventional composite cured for 20, 30, and 40 seconds. The microhardness of samples was measured at 0.1, 2, 2.5, 3, 3.5, 4, and 4.5mm depths using a Vickers hardness tester. The results were analyzed using ANOVA, t-test, and Tukey’s test.Results: The x-tra fil, Tetric N-Ceram and Grandio had maximum microhardness at 0.1mm depth after curing for 40 seconds. The microhardness decreased as the depth of composite increased. Microhardness of x-tra fil was higher than that of Tetric N Ceram. By increasing the curing time, the microhardness value of x-tra fil significantly increased up to 2mm depth. In Tetric N-Ceram, by increasing the curing time from 20 to 30 seconds microhardness increased significantly (P<0.05) by up to 3.5mm depth. By increase from 20 to 30 seconds, no significant change occurred in microhardness of Grandio samples at 0.1 and 2mm depths, but further increase from 30 to 40 seconds significantly increased the microhardness at all depths (P<0.05).Conclusion: The maximum microhardness was obtained for x-tra fil at 0.1mm depth following 40 seconds of curing. Microhardness in deep areas (>2mm depth) depends on the type of composite, curing time and depth. Overall, 20 seconds of curing for x-tra fil and 30 seconds for Tetric N-Ceram seem appropriate

Threatened fishes of the world: Paracobitis vignai Nalbant and Bianco, 1998 (Nemacheilidae)

Paracobitis vignai is a Nemacheilid loach endemic to the Sistan basin. It occurs in Helmand River and its related reservoirs in Sistan-va-Baluchistan Province in southeastern Iran and probably in Afghanistan. This species is currently endangered due to habitat loss or degradation, damming and droughts. Therefore, this paper reviews the available data on taxonomy and distribution of P. vignai, provides its morphometric features, and recommends actions for its conservation

Osteological characteristics of Turkmenian stone loach, Paraschistura cristata (Cypriniformes: Nemacheilidae)

Formerly the Turkmenian stone loach was the only member of the genus Metaschistura based on osteological characters. But recently, it is placed in the genus Paraschistura based on mtDNA COI data. To provide a detailed description of the osteological characteristics of Paraschistura cristata (Berg 1898), ten specimens of P. cristata were collected from the Hari River basin in Iran and their osteological characteristics were examined. According to the results, P. cristata is osteologically characterized by a foramen in the ventral part of the exoccipital, two extra urohyals, sesamoid ossifications, trapezoid-shaped prevomer, three basibranchials, five hypural, lack of bony bridge between the parietal and pterotic, having over 20 procurrent rays supporting the adipose crest. The detailed skeletal description of P. cristata showed that this species can be easily distinguished from the related genera. Despite the mtDNA COI result, the osteological data of this species showed some features to describe it as a distinctive genus, but this needs the osteological data of the all other Paraschistura species to be compared

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