Caspian Roach Research Articles

Cryptosporidium spp. and Eimeria spp. (Apicomplexa: Eimeriorina) of freshwater Cyprinid fish species in the Kura River basin in Azerbaijan territory.

This study aims to determine the prevalence of Cryptosporidium and Eimeria spp. oocysts in fish specimens in the river Kura. It was conducted during the 2021-2022 at two sites: Mingachevir reservoir in central Azerbaijan and in Neftchala district where the river finally enters the Caspian Sea through a delta of the Kura River estuary. The diagnosis of oocysts was performed microscopically. Fine smears from the intestine epithelial layers stained by Ziehl-Neelsen for Cryptosporidium oocysts. To identify Eimeria oocysts, each fish's faecal material and intestinal scrapings were examined directly under a light microscope in wet samples on glass slides with a coverslip. Results revealed a prevalence of Cryptosporidium and Eimeria species infections in fish hosts from both territories Rutilus caspicus, Alburnus filippi, Abramis brama orientalis and Carassius gibelio. Of 170 investigated fish specimens, 8.8% (15/170) were infected with Cryptosporidium species oocysts. Eimeria species oocysts were identified in 20.6% (35/170). The presence of Cryptosporidium and Eimeria infections in fish specimens are natural infections. However, their presence in fish species may be attributed to the age of the fish species and water pollution. This is the first report regarding the prevalence of Cryptosporidium oocysts in fish species in Azerbaijan.

Nucleotides supplementation (Nucleoforce fish™) in Caspian roach (Rutilus caspicus) diet: Growth performance, skin mucosal immune response, and resistance to salinity stress

In this study, the growth, epidermal mucosal immunity, expression of growth-related genes, cross-protection, and resistance to salinity stress of Caspian roach were scrutinized in response to dietary levels of nucleotides (NT). Accordingly, 1200 fish (0.51 ± 0.01 g) were fed ad libitum with a basal diet (38.88 % crude protein and 10.04 % crude lipid in dry basis) containing incremental levels of NT at 0 (NT-0; control), 0.3 g kg−1 (NT-0.3), 0.6 g kg−1 (NT-0.6), and 1.2 g kg−1 (NT-1.2) for 8 weeks in triplicates. The growth performance was significantly increased in the fish fed with NT-0.6 and NT-1.2 diets compared to the control group (p < 0.05). A significant elevation in the growth hormone and insulin-like growth factor-I gene expression was recorded in NT-added groups at 0.6 and 1.2 g kg−1 compared to the control group (p < 0.05). In contrast to the control group, feeding on NT-0.6 and NT-1.2 diets had a remarkable effect on the skin mucus soluble protein and immunoglobulin levels (p < 0.05). After the feeding trial, we examined how salinity stress (15 g/l salinity) lonely and salinity stress under non-lethal thermal shock (+10 °C) affected heat shock protein (HSP70). Then, the mRNA expression of HSP70 gene from the gill was analyzed at 0, 2, 8, and 24 h post-challenge tests. The HSP70 gene expression level was approximately up-regulated more than 2-fold in NT-6 and NT-1.2 treatments compared to the control group under the salinity stress. Altogether, this research represents that the addition of NT at 0.6 and 1.2 g kg−1 in Caspian roach diet can improve overall performance and resistance to salinity stress.

The protective effect of vitamin C on growth, digestive enzymes, immune response, and gill histology in Caspian roach (Rutilus rutilus caspicus) under diazinon stress

In recent years, the increase in the use of agricultural pesticides has endangered the production of marine creatures. However, exposing farmed creatures to water contaminated with pesticides is one of the current challenges. This study aims to investigate the defensive impact of diets containing varying amounts of vitamin C on the growth, digestive enzyme activity, immune response, and resistance of Caspian roach (Rutilus rutilus caspicus) exposed to diazinon. Fish (average weight: 1.12 ± 0.17 g) were fed diets containing 0 (control; C0), 500 (C1), 1000 (C2), and 1500 (C3) mg/kg of vitamin C for 56 days. Then they were exposed to diazinon stress for 14 days (0.32 mg/liter). The highest final weight and lowest feed conversion ratio were obtained in fish fed a diet containing vitamin C. The highest protease activity and lowest amounts of lipase and amylase were observed in the C3 group. At the end of the feeding period, lysozyme activity, total immunoglobulin amount, and complement (ACH50) in the C3 treatment were significantly higher than in the control treatment. After the stress period, lysozyme and complement activity were higher in all groups fed vitamin C supplements than in the control treatment. The highest levels of stress indicators (cortisol and alkaline phosphatase) were detected in the control group before and after stress. Based on the preparation of gill tissue sections, most lesions included edema, hyperplasia, adhesion of secondary lamellae, and necrosis of gill-covering cells. Overall, the results indicate that adding vitamin C to the diet can be used as a sustainable bioremediation tactic and reduce the adverse effects of diazinon exposure in Caspian roach.

The Study of Caspian Roach (Rutilus caspicus) Fry Health Fed with Phytobiotic-Supplemented and Salinity Stress Resistance with Emphasis on Gill Tissue Pathology.

Herbal treatment augments immune and antioxidant responses and suppresses stress in fish. Ginger (Zingiber officinale) is a popular plant with medicinal uses because of its immunostimulant, antimicrobial, and antioxidant characteristics. This study aimed to investigate the effects of ginger (Z. officinale) on growth, digestive enzymes activity, antioxidant and immune response, and salinity stress resistance of Caspian roach (Rutilus caspicus). Fish (0.98 ± 0.09 g) were divided into four treatment-fed diets containing 0 (control, Z0), 10 (Z10), 20 (Z20), and 30 (Z30) g/kg ginger powder for 56 days and then subjected to 2 g/L salinity stress for 48 hr. The highest final weight of specific growth rate (SGR), superoxide dismutase (SOD), and catalase activity and the lowest final weight of feed conversion ratio (FCR) and malondialdehyde (MDA) were observed in fish-fed diets containing 10 and 20 g/kg ginger inclusion. Intestinal protease activity significantly increased in Z10 treatment, and the highest amylase and lipase activities were related to control, including 10 g/kg ginger in the diet compared to the control group had a significant effect on immune indices such as immunoglobulin M (IgM) and ACH50 (p < 0.05). The highest lysozyme was obtained in Z20 treatment, which had a significant difference in the control (p < 0.05). Cortisol and glucose levels were significantly lower in ginger treatments than the control before and/or after salinity stress. Histopathologic results showed that hyperplasia, edema, expansion of secondary lamella, epithelial cells, and necrosis of gills were most common lesions. However, the results of this study demonstrate that using ginger powder in addition to improving of growth, it can be also effective in survival rate of Caspian roach fingerling as an endangered species exposed to salinity stress.

The Low Ontogenetic Diet Diversity and Flexibility of the Pike-Perch, Sander lucioperca (Linnaeus, 1758) (Osteichthyes, Percidae): A Case Study

This study reveals the diet of pike-perch from two habitats within the Tersko-Caspian region. The feeding habits of pike-perch in the Sulak and Terek rivers and Tersko-Caspian region were investigated based on 354 specimens sampled monthly from a commercial catch in 2019. Their diet consisted of different prey, with fish representing the most important prey group (up to 90%). Rutilus caspicus dominated with a frequency of occurrence of 20.5, and Aspius aspius, Perca fluviatilis, and Chondrostoma oxyrhynchum, had 13, 9.5, and 8.3%. In the earlier ages 1+ and 2+, zooplankton dominated, followed by mysids and chironomids, which continues into the older ages but at decreasing rates. Analysis of monthly variations in stomach fullness indicated that feeding intensity fluctuated in time, with the highest values in March–April, and lowest in September and November. It was found that the diet of pike-perch in the western Caspian changed considerably from season to season. They begin to actively feed after wintering and before, or even during, spawning period. The spectrum of the diet of Sander lucioperca includes more than 20 elements, mainly juveniles of commercially valuable fish. This fish is characterized by a relatively low ontogenetic diet diversity and flexibility, which makes it sensitive to environmental changes, including anthropogenically induced ones. This fish partially compensates for this disadvantage with its lifestyle, namely, its active foraging movements and migrations from fresh water to salt water and back, following its prey species.

Biological characteristics of main commercial fish of the shamkir reservoir

In 2019-2022, an ichthyological study of six species of the main commercial fish was carried out at the Shamkir reservoir on the Kura River. Studies have shown that the ratio of males and females among the main fish species caught in this reservoir was approximately 1:1 for bream (Abramis brama orientalis), zander (Sander lucioperca) and carp (Cyprinus carpio), 2:3 for Prussian carp (Carassius auratus gibelio), 5:4 for Caspian roach (Rutilus caspicus), and 3:2 for Danubian bleak (Chalcalburnus chalcoides). In all fish species, the difference between the body weight of males and females without viscera was greater than the difference between their total body weight, which was due to the presence of eggs in females. For the same reason, the fullness according to Fulton of males and females more differs, than fullness according to Clark. Comparition of the different age groups shows that the growth speed of lenth and mass of the carp and zander were higher than of the rest fish. The growth rate of roach and Danubian bleak was the lowest compared to other fish.

Interactive effects of culture systems (biofloc and clear water) and dietary protein levels on growth, digestive activity, mucosal immune responses, antioxidant status, and resistance against salinity stress in the Caspian roach (Rutilus caspicus) fry

This experiment aimed to evaluate effects of culture system and dietary protein level on performance of the Caspian roach fry. Fish (0.99 ± 0.06 g) were stocked into 12 tanks (water volume, 50 L) at a stocking density of 100 fish per tank. The experiment was designed with two culture systems (biofloc, BFT and clear water, CW) each with 38 and 28% dietary protein levels following a 2 × 2 factorial design. After 60 days, fifty fish were randomly captured from each tank and exposed to salinity challenge (13 g/L) for 72 h. On days 45 and 60, total ammonia nitrogen (TAN) values were significantly higher in CW treatments, then BFT38 treatment, and lower in BFT28 treatment. The final weight, weight gain, and SGR in BFT and CW38 treatments were significantly higher and FCR was lower than the CW28 treatment. The protein efficiency ratio was highest in the BFT28 treatment. Also, amylase, lipase, and protease activities in fish cultured in BFT system were significantly higher than the CW system. After salinity stress, skin mucus cortisol values were significantly lower and survival rate was higher in BFT groups compared to the CW treatments. After 72 h stress, the mucus glucose values in BFT and CW38 treatments were significantly lower than the CW28 treatment. Before stress, the mucus alkaline phosphatase (ALP) activity was lowest in the CW28 treatment. Skin mucus protease activity was significantly higher in BFT groups at before and all sampling times after salinity challenge. The skin mucus lysozyme activity and total protein value in all treatments increased at 24 h post stress, and then only returned to the pre-stress values at 48 h for the BFT38 treatment. After salinity stress, lysozyme activity in BFT and CW38 treatments was significantly lower than the CW28 treatment. After 48 h stress, the highest mucus ACH50 activity was observed in the BFT38 treatment, but it was not significantly different from the BFT28 and CW38 treatments. After salinity stress, muscle catalase and SOD activities were significantly higher and MDA content was lower in BFT treatments than the CW treatments, suggesting that biofloc can enhance the antioxidant defense in fish. Overall, biofloc system and high dietary protein level beneficially affect growth, skin mucus immune responses, and resistance against salinity challenge in fish. Also, microbial proteins contained in bioflocs as a supplemental protein source can compensate 10% reduction of protein in the Caspian roach fry diet.

ЗАРАЖЕННОСТЬ КАРПОВЫХ РЫБ ЛИЧИНКАМИ ПАТОГЕННЫХ ДЛЯ ЧЕЛОВЕКА ГЕЛЬМИНТОВ И БАКТЕРИЯМИ В НИЖНЕЙ ЗОНЕ ДЕЛЬТЫ РЕКИ ВОЛГИ В СОВРЕМЕННЫЙ ПЕРИОД

Recreational and artisanal fishing is very widespread in the Astrakhan Region; its primary targets are cyprinids, which are susceptible to epedemiological threats. Food products derived from the biological resources harvested during such fishing are not subjected to the processing in specialized facilities, and therefore, safety of the final product for its consumer cannot be ensured. In this region, the diseases, the agents of which are transmitted through fish and the products of its processing, are annually recorded among the population. Sanitary and parasitological control is one of the components in the set of measures for the prevention of these diseases. This work was aimed at evaluation of the infection level in some species of commercially valuable cyprinids in the Lower Volga River Delta with bacteria and larvae of pathogenic helminths capable of causing the development of diseases in humans. An incomplete helminthological survey of Caspian roach, common bream, white bream, crucian carp and rudd, as well as microbiological examination of their muscle tissue have been carried out in accordance with the requirements of the regulatory documents currently in force with application of methods described in State Standards. Larvae belonging to four species of human-pathogenic parasites have been recorded in the parasitic fauna of the Caspian roach, rudd, and white bream. Common bream was infected by larvae belonging to two species of such helminths. The identified larvae of pathogenic trematodes and nematodes were viable. The level of bacterial contamination of fish muscle tissues did not exceed the standard-prescribed limit, and the sanitary indicator microorganisms were absent. The results of the parasitological study indicated the need for mandatory disinfection of cyprinid fish from larvae of pathogenic helminths.

О мерах по сохранению и восстановлению популяции воблы Rutilus Rutilus Caspicus (Jakovlev, 1870)

In recent years, the state of the Caspian roach reserves has been repeatedly discussed at different levels and sites. The number of this species is declining, catches are falling. Based on the instructions of the Volga-Caspian Scientific and Commercial Council of the Volga-Caspian Fisheries Basin, a draft comprehensive program for the conservation and restoration of roach stocks is being developed, in which it is planned to consider the imposed restrictions on fishing, the possibility of artificial reproduction, the need for in-depth monitoring of the population. Observing negative trends for a number of years, understanding the social significance of the species, immediate emergency measures are needed to preserve and restore the Caspian roach in order to avoid its loss.

Out-of-season reproduction of kalam fish (Rutilus caspicus) using temperature and photoperiod

Out-of-season reproduction of kalam fish (Rutilus caspicus) using temperature and photoperiod

Concentration of heavy metals in different tissues (muscle, liver, gonad, skin, kidney) of Roach (Rutilus rutilus caspicus) in Guilan coasts of the Caspian Sea

Concentration of heavy metals in different tissues (muscle, liver, gonad, skin, kidney) of Roach (Rutilus rutilus caspicus) in Guilan coasts of the Caspian Sea

Effect of Short-term Elevation Temperature and Salinity Stress on Caspian Roach, Rutilus caspicus

Effect of Short-term Elevation Temperature and Salinity Stress on Caspian Roach, Rutilus caspicus

Artificial reproduction of Caspian roach, Rutilus caspicus following stimulating ovulation with Ovaprim, Ovopel, and their combinations under controlled conditions

The aim of this study was to evaluate the efficiency of different hormonal agents and their combinations for spawning induction of females Caspian roach, Rutilus caspicus. Five groups of fish were injected intraperitoneally as follows: two injections of Ovaprim (T1), two injections of Ovopel (T2), a priming dose of Ovopel with a resolving dose of Ovaprim (T3), a priming dose of Ovaprim with a resolving dose of Ovopel (T4), and two injections of sterile 0.9% NaCl solution as a control group. The results showed that no fish ovulated in the control group. In hormone-treated groups, no differences were observed in ovulation success (P > 0.05). The shortest latency time and highest working and relative fecundities were observed in fish stimulated with two injections of Ovaprim (T1 group). The mean values of fertilization success in treated fish were in the range of 87.9–93.1% and the highest values were observed in T3 and T1 groups (P < 0.05). The best results in terms of ovulation index (92.1%), hatching rate (93.7%), and survival up to the eyed egg stage (89.4%) were achieved after administering two injections of Ovaprim (T1 group). There were no significant differences in the incubation time and embryos survival rates up to absorbing the yolk sac among different groups (P > 0.05). Overall, the best results of controlled reproduction of Caspian roach were obtained after using two injections of Ovaprim. Consequently, the Ovaprim is more suitable for restocking and aquaculture purposes of endangered populations of Caspian roach.

Acipensor Stellatus, Rutilus (Rutilus) Caspicus, Leuciscus Cephalus Orientalis of the Fauna of the Nakhchivan Autonomous Republic Faunistic Analysis of Fishes

Summarizing the obtained literature materials and the results of our research, it was determined that 33 fish species or subspecies consisting of 6 groups, 9 chapters and 28 genera are distributed in the waters of Nakhchivan AR. Acipenser stellatus - A fairly large fish, its adult individuals in the ichthyofauna of Azerbaijan vary in body length from 105 to 225 cm and weight from 9 to 73 kg. The body stretches. Rutilus rutilus caspicus - A number of esophageal teeth, gingival teeth are sparse and rough. It is the only widespread species in Azerbaijan. The body, slightly flattened on the sides, is covered with fairly large scales. The eyes are large, the iris is red. Leuciscus cephalus orientalis - Fish is distinguished by broad and rigid forehead, cylindrical and large scales. The eyes are big and bright.

The improving role of savory (Satureja hortensis) essential oil for Caspian roach (Rutilus caspicus) fry: Growth, haematological, immunological, and antioxidant parameters and resistance to salinity stress

Essential oils (EOs) due to their bioactive compounds can be considered suitable dietary supplements to achieve sustainable aquaculture. The present experiment was conducted to evaluate the effects of supplementation of Caspian roach fry (Rutilus caspicus) diet with different doses of savory essential oil (SEO) (Satureja hortensis) on growth performance, haematological parameters, serum and mucus immunological indices, serum antioxidant indices, and salinity stress resistance. Caspian roach fry (2.29 ± 0.07 g) were fed with four experimental diets including basal diet as control, and basal diet incorporated with 100, 200, or 400 mg/kg diet of SEO (SEO1, SEO2, and SEO3 respectively) for 60 days. At the end of the experiment, the lowest feed conversion ratio (FCR) as well as highest final weight (FW), weight gain (WG), and specific growth rate (SGR) were observed in fish given the SEO2 diet (P < 0.05). The SEO3 group showed the lowest FW, WG, and SGR which was significantly lower than other groups (P < 0.05). Survival rate of the SEO1 and SEO2 treated groups showed a significant increase compared to the SEO3 and control groups (P < 0.05) with the highest rates found in fish received SEO2. All groups receiving SEO showed significantly higher haemoglobin (Hb) and number of white blood cells than control group (P < 0.05). The best serum levels of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), and malondialdehyde (MDA) were observed in fish treated with SEO2, which showed a significantly different from the control group (P < 0.05). All SEO treated fish showed significant increase in serum total immunoglobulin (total Ig), lysozyme (LYZ), and alternative complement pathway haemolytic activity (ACH50) compared to the control group (P < 0.05) with SEO2 showing the best results. Also significant improvement of mucus total Ig, LYZ, ACH50, protease and alkaline phosphatase (ALP) activities were found in treatments receiving SEO compared to those of control group (P < 0.05). All SEO treatments showed significantly higher resistance to salinity stress than those in the control group (P < 0.05). Overall, our results revealed that SEO inclusion can improve growth performance, antioxidant enzymes activities, immune responses as well as resistance of R. caspicus and 200 mg/kg diet is recommended.

Length Weight Relationships of Rutilus caspicus during 2016-2018 in the Southeast Caspian Sea - Golestan province

One of the most important data in the stock assessment models is knowing the coefficients of length weight relationships of a species. In this study, the results of the length weight relationships of the Caspian roach in the years 2016 to 2018 were evaluated to investigate the trend of changes in coefficients a and b based on nonlinear regression. The total length of the study population in this study was from 12/31 to 30.02 cm and the total weight was between 28 and 346 g. The maximum length and weight were recorded in 2016, 27.26 cm and 262 g, in 2017, 22.28 cm and 178 g, and in 2018, 30.02 cm and 346 g. Relationship between population length and weight in 2016, W= 0.054TL3.26 (r2 = 0.94), in 2017, W= 0.0032TL3.47 (r2 = 0.96) and in 2018, W=0.0090TL3.09 (r2=74) was obtained. The results showed that the growth pattern in 1995 is allometric negative and in 1996 and 1997 is allometric positive for this species in the study area. The condition factor was 0.53±0.05 in 2016, 0.35±03 0.03 in 2017 and 0.94±0.04 in 2018.

К ИЗУЧЕНИЮ БИОЛОГИИ ВОБЛЫ RUTILUS RUTILUS CASPICUS (JAKOWLEV, 1870) КРАЙНОВСКОГО ПРИБРЕЖЬЯ КАСПИЙСКОГО МОРЯ

The offshore zone of the western coast of the Caspian Sea is one of the most highly productive. Of the 63 species of fish that live in the Caspian Sea, 34 species are found on the Krainovsky coast, 42 % of which are carp. The most numerous is the roach Rutilus rutilus caspicus (Jakowlev, 1870), which makes up 50–86 % of the number of semi-passerine and river fish. The article presents the results of studies of the peculiarities of the biology of the roach Rutilus rutilus caspicus of the Krainovsky coast of the Caspian Sea. The roach is noted in the catches constantly. Her age in the networks ranges from 2 to 10 years. The share of 3-5-year-olds accounts for 81 %. Females in catches make up 66 %, males - 34 %. The parameters of the Bertalanfi equation are characterized by the following values: L =38.8 cm, K = 0.12, t° = -2.67. The fecundity of the roach on average is 30.2 thousand eggs and tends to increase with increasing length and weight of the fish. As the roach grows, the composition of its food changes significantly. The maximum fed roach length from 10 to 20 cm.

КОЭФФИЦИЕНТЫ НАКОПЛЕНИЯ ХИМИЧЕСКИХ ЭЛЕМЕНТОВ В ОРГАНАХ И ТКАНЯХ РУССКОГО (ACIPENSER GUELDENSTAEDTII, BRANDT, 1833) И ПЕРСИДСКОГО (ACIPENSER PERSICUS, BORODIN, 1897) ОСЕТРОВ КАСПИЙСКОГО МОРЯ

The article is focused on the possible ways of accumulating chemical elements (zinc, copper, chromium, nickel, lead, mercury) in the organs of aquatic organisms. In the course of the study, the coefficients of accumulating the chemical elements in the organs and tissues were calculated for the Russian (Acipenser gueldenstaedtii, Brandt, 1833) and Persian sturgeons (Acipenser persicus, Borodin, 1897) relative to the water of the northwestern part of the Caspian Sea, bottom sediments and the main objects of their food (Khvalyn goby (Neogobius caspius), Sandpiper goby (Neogobius fluviatilis), Caspian goblin (Benthophilus microcephalus), roach (Rutilus rutilus caspicus)). The studies were carried out according to the standard method of atomic absorption spectrometry. It is shown that the main source of accumulating the studied chemical elements in the organs and tissues of the Russian and Persian sturgeons is the water of the northwestern part of the Caspian Sea. It was found that the bottom sediments of the Caspian Sea act as an additional source of zinc and mercury found in the liver and kidneys of sturgeon species. Based on the calculated accumulation coefficients of chemical elements, there was revealed a predominantly alimentary nature of accumulating copper, nickel and mercury in the organs of both sturgeon species.

Microplastic fibers in the gut of highly consumed fish species from the southern Caspian Sea

This study assesses the frequency, distribution, characteristics, and chemical composition of microplastics (MPs) in the gut of highly consumed fish species, namely leaping mullet (Chelon saliens), common carp (Cyprinus carpioi), and Caspian kutum (Rutilus caspicus), in the southern Caspian Sea biome. Fibers are found to be the only shape of MPs. Black MPs and polystyrene, polypropylene, and polyethylene terephthalate polymers are dominant. MP frequency is highest in leaping mullet's gut, while kutum specimens exhibited the lowest MP frequency, reflecting that leaping mullet is a neritic species and thus highly exposed to MP influx in shallow coastal water, while the other species are benthopelagic. The estimated condition index reflected a significant difference between the species, implying that MPs may pose adverse health impacts on leaping mullet and common carp, with no undesirable effect on Caspian kutum. No significant relationship exists between biological parameters and the MP frequency in the fish gut.

Evaluation of Histopathological Effect of Roach (Rutilus rutilus caspicus) in Exposure to Sub-Lethal Concentrations of Abamectin

With the advancement of technology and the development of agriculture, the use of pesticides in this industry has also increased. The aim of this study was to investigate the effects of Abamectin toxin on survival and intestinal tissue of Caspian Roach as one of the valuable species in the Caspian Sea. For this purpose, 126 fingerlings fish were exposed to a different level of Abamectin for 96 h. Data analyzed showed that there was a significant correlation between fish mortality rate and Abamectin concentrations. Histological assays showed some typical tissue damages such as vaculation, necrosis, bleeding, epithelial degeneration, the intestinal villi destruction, deformation, and destruction of epithelial cells. Moreover, some clinical signs occurred like increasing operculum movement, swimming near the water surface, anxiety, and death with open mouth. The results of the present study showed that Abamectin can have toxicity effects on Caspian roach, also to sub-lethal concentrations, leading to several tissue damages and reduced survival rate of fish.