فصلنامه بوم شناسی آبزیان
سال یازدهم شماره 4 (پیاپی 43، بهار 1401)

Sediment samples were collected from 8 sites in the northern areas of Qeshm Island, Iran to determine the total and partial concentrations of heavy metals including copper (Cu), lead (Pb), nickel (Ni), cadmium (Cd), and Iron (Fe), in February 2016. A combination of nitric acid and perchloric acid was used to determine the total concentrations and sequential extraction method was used to analyze the partial concentrations of different geochemical parts of the sediment. Metal concentrations were measured by flame atomic absorption spectrometry. Contamination factor (CF), pollution load indices (PLI), enrichment factor (EF), geoaccumulation index (Igeo), risk assessment code (RAC) and potential ecological risk (PER) were calculated to determine the ecological risk. The results showed that the concentrations of heavy metals were Fe>Ni>Pb>Cu>Cd, respectively. The results of sequential extraction showed that Cd (25.98%) and Cu (21.40%) had the highest bioavailability among the other heavy metals. Most of each element was in the part of reducible (Fe-Mn oxide bound) (F3) and residual (F5). According to the RAC, only Cu and Cd were identified as high-risk at Station 5, and for other stations and other metals, the results showed low, medium or no risk. Evaluation of enrichment factor showed significant contamination for most of the metals tested, including Cd, Ni and Pb, which confirms the results from other indices. Finally, it can be said that the results of various indices that have been measured in relation to the mentioned heavy metals, showed that these elements have low to moderate pollution in the study area.

Recently, Luciobarbus conocephalus from the Hari River was reported for the first time, but there is doubt about the validity of this species between authors, because some of them placed it as a subspecies or synonym of L. capito. Therefore, the present study was conducted to investigate the status of phylogeny and the validity of this species. For this purpose, specimens captured from Hari River (between the lower of Dosti dam and Khatoun bridge) using an electrofishing device. After DNA extraction from the fins, Cytb gene was amplified and sequenced. Using sequences, the phylogeny tree was plotted by Bayesian inference and Maximum likelihood estimation. According to the results, Hari barbel is a valid species and differs from Bulatmai barbel. Colonial jaundice was found in genealogical trees depicted in a separate cluster of L. capito with high support. Hari barbel was found in phylogenetic trees depicted in a separate cluster of L. capito with high support, and the Alignments results of Cytb gene of this species also differed in 11 unique loci with L. capito. In addition, the mean genetic distance of K2P for the two species of Hari and Bulatmai barbels was about 1.3%, which seems to be an acceptable distance for the valid species of the genus Luciobarbus.

Qom province has a dry climate according to the Domarten classification, but some aquatic and wet habitats in different parts of the province have provided the possibility of growing various aquatic and waterfront plants. In this study, plants that grew in aquatic and moist habitats of the province were collected in different seasons of the year and, after transfer to the herbarium, were identified based on relevant botanical literature. A total of 73 taxa including four species of green macroalgae (charophytes), one species of bryophyte, and 68 species of vascular plants from different parts of the province were identified. Dicotyledonous plants accounted for 77% and monocotyledonous plants for 12% of the studied habitats. Amaranthaceae and Caryophyllaceae were the most present families. Among the collected plants, therophytes and hemicryptophytes are the most abundant life forms, followed by geophytes. In terms of phytogeographical distribution, most of the vegetations of the studied habitats were assigned to the Irano-Turanian chorotype, followed by pluriregional elements, Irano-Turanian / Mediterranean, and Euro-Siberian / Irano-Turanian / Mediterranean. Generally, the observed chorotypes revealed the ecotone situation of Qom province.

Fish mucus layers are the main surface of exchange between fish and the environment, and they possess important biological and ecological functions. In the present study, the antioxidant activity (reducing power, total antioxidant capacity, and free radical scavenging of DPPH) and cytotoxicity (test of saltwater shrimp larvae) of four species of Solea elongate, Euryglossa orientalis, Netuma bilineata, Muraenesox cinereus were investigated. The results showed that E. orientalis fish mucus had the highest reducing power (1.6 ± 0.2), N. bilineata fish mucus had the highest total antioxidant capacity (0.93 ± 0.3) and the highest percentage of free radical scavenging DPPH (89 ± 0.2). In the cytotoxicity test, the highest mortality rate under the influence of S. elongate mucus was about 97.5 ± 2.5. The results of the present study showed that fish mucus can be introduced as a potential source of natural biological compounds with high antioxidant activity and cytotoxicity.

Understanding of habitat requirements of a fish species is a research priority for its management and conservation. The biological characteristics and habitat requirements of Alburnoides tabarestanensis have not been studied yet. Therefore, this work aimed to study large-scaled i.e. water velocity, depth, river width, and bed type habitat suitability indices of endemic Tabarestan spirlin in the Kela River (a tributary of the Babel River, Caspian Sea Basin). For this purpose, a total of six stations along this River were sampled using an electrofishing device in a 30 m length of river with three replications. Based on the results, the preferred range of environmental variables of Tabarestan spirlin were a water depth of 17-20 cm, river width of 8.8-4.8 m, water current of 5-6 m / s, bed index of 3.5-8.8. The bedrock diameter was 7.5-5 cm. The results also showed that the selected habitat characteristics of Tabarestan spirlin are those with higher depth, boulder substrate type, lower width and lower water current that can be adversely affected by human activities such as sand and water harvestings.

Leukemia is one of the most important diseases that affected human lives. Therefore, study of effective factors in order to control of this disease is very essential. This study was investigated the effect of cytotoxicity of extracts (n- Hexane, Diethyl ether, Methanol) from the algae Padina tenuis  Bory de Saint-Vincent on leukemia cell line. For this purpose, the required extracts of Padina tenuis  Bory de Saint-Vincent were prepared by rotary which was collected from the Namakdan rocky shores, Qeshm Island. Subsequently, human leukemia cell line was cultured in RPMI culture medium with 10% fetal bovine serum. The cytotoxic effect of different concentrations (10, 30, 75, 150, 300, 500 µg / ml) was measured by MTT method. Hexane, diethyl ether and methanol extracts were able to inhibit the proliferation of human leukemia cells at 258 µg / ml, 90 µg / ml and of 122 µg /ml concentrations, respectively, in vitro. Also, with increasing the concentration of extracts, the percentage of metabolic activity of cancer cells decreased. The results showed a significant difference in the effect of different solvents against blood cancer cells at a significance level of 95%

Oxynoemacheilus chomanicus is an endemic loach species in Choman River drainage of Kurdistan Province (Iran). In this study we evaluated the morphological variation of body shape among different population of this species from three main tributaries of Choman River; Baneh, Boein and Shooei Rivers. A total of 92 specimens were examined using geometric morphometric method. Using the photographs from the left side of specimens 14 landmarks and 2 semi-landmarks points were selected and analyzed using PCA and CVA methods. Results obtained indicated significant differences between studied populations, especially in head, caudal peduncle and dorsal fin base parts of the fish body.