Iranian Journal of Ichthyology
Volume:2 Issue: 1, Mar 2015

The systematics, morphology, distribution, biology, economic importance and conservation of the spiny eel (Mastacembelus mastacembelus) of Iran are described, the species is illustrated, and a bibliography on this fish is provided. The single species is distributed in southern Iranian basins, including Karkheh, Karun, Jarrahi and Helleh river basins, mostly part of the Tigris River and Persian Gulf basins.

Some 190 specimens of Sefidrud loach, Oxynoemacheilus bergianus, were collected from Aras River (Northwestern Iran) and age, size, and some biological characteristics of the samples were investigated from March to July 2013. The maximum age was 3 years. The specimens ranged in size from 42 to 64mm for males and 45 to 61mm for females in total length, weighing from 0.62 to 2.03g for males and 0.63 to 1.66g for females. Length-weight relationship was estimated as W= 0.00005TL2.81 for females, W= 0.000005TL3.11 for males and W= 0.000008TL2.97 for the sexes combined. Sex ratio was 1M:0.9F, in favor of males (P

Various human pressures are affecting the aquatic biocoenosis in running waters of Iran - similar to many other areas of the world. Overall 190 sites, 88 at salmonid (44 reference/impacted respectively) and 102 at cyprinid (50 reference/52 impacted) streams of the southern Caspian Sea basin were investigated in terms of human pressures present and the related impact on fish assemblages. In total, 30 potential human pressure variables acting on biological communities at four different spatial scales and associated with seven pressure types (land use, connectivity disruption, morphological alteration, hydrological alteration, water quality deterioration, biological (i.e. alien species, overfishing etc.) and non-predicted pressures) were identified. Further, a regional pressure index was derived, taking additive effects of multiple pressures into account. Our analysis showed that the most dominating human pressure in both zones was land use (i.e. urbanisation in salmonid streams and agriculture land use in cyprinid streams) followed by water quality and morphological pressures especially in salmonid streams and hydrological and morphological pressures in cyprinid streams. Most sites of the salmonid zone were affected by double and triple pressures, whilst multiple pressures were dominating in the cyprinid zone. After analysing the fish assemblages and structural and functional traits, eight fish metrics remained in the salmonid zone and 25 metrics in the cyprinid zone – both for reference sites. The response of fish metrics on human impacts was tested with Mann–Whitney U test and regression analysis. Some fish metrics (e.g. total species, herbivorous species) showed significant positive reactions to the human pressures in the salmonid zone but significant negative reactions in the cyprinid zone. Furthermore, some metrics (e.g. number of alien species or eurytopic species) responded similarly in both zones. However, some fish metrics of the cyprinid zone (e.g. planktivorous species or phytophilic species) did not show any significant reaction.

The toxic impact of copper sulfate in lethal and sublethal concentrations was investigated on gill of grass carp, Ctenopharynogodon idella. In this investigation, 27 specimens were used as control group and three treatment groups were treated with 2.5 and 5mg/l of copper sulfate. Gill samples were collected from each treatment after 96hr and lesions were analyzed by light microscopy. In histopathological study of the gill tissues, hyperplasia was clearly obvious in treatment specimens. In all of the treated groups, heavy gill-mucus response was observed, which indicate a direct relation with high concentrations. Also, in histological study of the gill, epithelial cells faced to hyperplasia, which increased with high copper densities. Primary lamellar cells wrinkling and also changing in formation were observed in chloride cells. This lesion enhanced in higher densities and in concentrations of 2.5 and 5mg/l, primary and secondary lamellar epithelial cells were degenerated.

The present study is related to the histochemical investigations on the changes in the intensity of reactions of axons, acid and neutral mucopolysaccharides, biologically active macromolecules, particularly glycogen and protein component as well as alkaline phosphatase (ALPase) and adenosine triphosphatase (ATPase) in the cells lining the olfactory epithelium of Catla catla. The intense reaction of silver stain was well-marked in the primary receptor cells and in the synaptic contacts between primary and secondary receptor cells. The maximum intensity of reaction of acid and neutral mucin as well as protein, was discernible in the secretory and non-secretory mucous cells. Various shades of glycogen were detected in the receptor cells, stratified epithelial cells and mucous cells. Concentration of ALPase was found to be associated with central core along with basement membrane. Acute ATPase activity was evidenced in the receptor cells, stratified epithelial cells and basal cells of olfactory epithelium and nerve fibers in the central core. Histochemical reactions in the various cells on the olfactory epithelium were discussed with the functional importance of the fish concerned.

Cobitis avicennae is a new described species from Iranian part of the Tigris basin and little information is available on its different aspects of its biology and holomorphology. Hence, this study was conducted to provide a detailed description of its osteological features. For this purpose, the specimens of C. avicennae were cleared and stained and a detailed description of its skeletal structure was provided. Cobitis avicennae can be distinguished from other Iranian members of the genus Cobitis by having 41 centra and two unbranched rays in the anal fin, lacking two processes in the middle part of the parasphenoid and presence of three basibranchial elements in the branchial apparatus.

This research was conducted to study the length-weight and length-length relationships and condition factor of six cyprinid fish species viz. Alburnus atropatena, Barbus lacerta, Capoeta capoeta, Carrasius gibelio, Romanogobio macropterus and Pseudorasbora parva from Zarrineh River (Urmia Lake basin, Iran). A total of 188 specimens ranging from 2.9 to 21.4cm in total length and 0.22 to 176g in total weight were collected. Based on the results, the values of b varied between 2.59 for C. capoeta, to 3.26 for A. atropatenae. All length-weight relationships were significant (P0.98). All linear regressions were highly significant (P