مجله علمی شیلات ایران
سال بیست و هفتم شماره 1 (پیاپی 105، فروردین و اردیبهشت 1397)

The aims of this study were to assess the anesthetic vigor and histopathological effects of peppermint (Mentha piperita) essential oils in common carp (Cyprinus carpio). The total number of 70 fish with the average weight and length of 8.52±1.54 g and 8.47±1.16 cm were anesthetized by various concentrations of peppermint essential oils including 200, 250, 300, 350, 400, 450 and 500 ppm using the immersion method. The average amounts of temperature, pH and the hardness of water were 22±2˚C, 7 and 981 mg/L, respectively. The time taken to reach different stages of anesthesia, loss of equilibrium, twilight anesthesia, balance recovery and complete recovery were measured after exposure of fish to various concentrations of peppermint essential oils. In order to determine the effects of various concentrations of peppermint essential oils including 200, 300, 400 and 500 ppm at time 0 and 24 h, the tissue samples that were taken from the liver, kidney and gill of fish were examined by light microscopy. The results showed that the maximum and minimum time taken to reach complete anesthesia were observed after 10±5.11 and 73±16 seconds of exposure to 200 and 500 ppm of peppermint essential oils, respectively. The minimum time taken for recovery was 300±8.4 seconds which belonged to the treatment of 200 ppm peppermint essential oils. Moreover, the results showed that by increasing the concentration of anesthetic substance, the induction of anesthesia was faster and the time taken for complete recovery from anesthesia was increased. Histopathological studies showed that the optimum concentration of 200 ppm peppermint essential oils had no side effects. Therefore, this anesthetic concentration of peppermint essential oils can be safely used.

Crimson snapper (Lutjanus johni Bloch, 1792) is the most important commercial species in the Persian Gulf and the Oman Sea. This species is caught by gillnets in the coastal waters of Bandar Abbas. In the present study, the gillnet with 17 cm stretched mesh size (knot to knot) is used for investigating the selectivity of gillnet used for catching the crimson snapper by length-girth relationships in the coastal waters of Bandar Abbas. Sampling was performed in May and July 2017. The total numbers of 1107 specimens were caught after 210 times of gillnetting. The weight, total standard length and girth of 4 points of body (locations of eyes, operculum, beginning of the dorsal fin and maximum girth) were measured for all specimens. Regression of length-girth, length-weight and selectivity curve were drawn based the data. Results showed that the total length was increased by increasing the body girth and weight of fish. Based on the body girth of two points including branch girth and maximum body girth, the selectivity of gillnet ranged from 62 to 76 cm in which the optimum length was 69 cm that is higher than Lm50. Therefore, it can be concluded that gillnet with 17 cm mesh size is suitable for catching crimson snapper.

Finding the suitable substitution for fish meal without any negative effect on fish performance is especially important for aquaculture development. In this research, the effect of substitution of fish meal with different levels of earthworm (Eisenia fetida) meal and garlic (Allium sativum) powder were studied on hematological and serum parameters of rainbow trout (Oncorhynchus mykiss) fingerlings. For this purpose, various diets were prepared containing different levels of substitution of fish meal with 0, 25, 50 and 75% of earthworm meal accompanied by 0 and 2.5% of garlic powder. Fingerlings with the average initial body weight of 30±0.27 g were reared in equal conditions for 56 days in 8 treatments and each treatment had three replicates. At the end of the experiment, the results of blood and serum biochemical indices assessments showed that the highest amounts of hemoglobin, hematocrit and WBC were observed in the treatments containing 25% earthworm meal with garlic powder, 25% earthworm meal with and without garlic powder and 75% earthworm meal without garlic powder, respectively whereas the lowest amount of RBC was observed in the treatment containing 50% earthworm meal without garlic powder. MCV, MCH and MCHC values in the treatment containing 0% earthworm meal with 2.5% garlic powder were significantly higher as compared to those of the other treatments except the control treatment (P

In this study, the effects of Lactobacillus plantarum KC426951 on growth, survival rate, blood and serum factors and gut bacterial flora of rainbow trout were investigated. For this purpose, 90 fish with an average weight of 12.94±0.35 g were fed for 8 weeks with the diets containing different amounts of encapsulated Lactobacillus plantarum including treatment 1 (107 CFU/g), treatment 2 (108 CFU/g) and the control treatment without Lactobacillus plantarum (T0). The results of this study showed that the highest weight gain, percent of body weight gain, specific growth rate and the lowest feed conversion rate were observed in the treatments 1 which were significantly different as compared to those of the control treatment (P0.05). In blood factors, the numbers of white blood cells in the treatments containing bacteria were significantly higher than the control treatment (P0.05). According to the results, the numbers of lactic acid bacteria in the treatments containing bacteria (1 and 2) were significantly higher than the control treatment. The total bacterial count in the treatment 1 was significantly higher than that of the other treatments (P

In the present study, the effects of enrichment of Artemia franciscana with fish oil and soybean oil accompanied with vitamin E were investigated on the structure of pyloric caeca in Persian sturgeon (Acipenser persicus) larvae. A total of 1500 Persian sturgeon larvae (with the average weight of 51±2 mg) were divided into 15 tanks. Larvae were fed for 17 days in 5 experimental treatments including the treatment C (non-enriched artemia), S15 (enriched artemia with soybean oil and 15% vitamin E), S30 (enriched artemia with soybean oil and 30% vitamin E), F15 (enriched artemia with fish oil and 15% vitamin E) and F30 (enriched artemia with fish oil and 30% vitamin E). From each traetment, 15 larvae were collected and were fixed in Bouin’s solution for histological studies. Histological results showed that both fish oil and soybean oil were the main and effective factors on the total area and histo area indices of the pyloric caeca and the enrichment of artemia with fish oil and soybean oil was significantly increased this factor as compared to that of the control treatment (P

Sea cucumbers produce various bioactive compounds especially secondary metabolites including Saponin. The aim of this study was to investigate antibacterial activity of the Saponin extracted from the Persian Gulf sea cucumber (Stichopus hermanni) in some gram positive and negative bacteria. Extraction was first done by ethanol 70% and then Saponins were separated through column chromatography with silica gel. Extracted Saponins were identified through thin layer chromatography (TLC) and high performance thin layer chromatography (HPTLC). Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were investigated via tubular dilution. Two groups of steroidal and glycosides Saponins with Rf 0.9 and 0.05 were respectively identified in fractions extracted by TLC. HPTLC results for a sample of extracted Saponin confirmed the existence of Saponin in sea cucumber regarding the Rf. The gram negative bacterium Pseudomonas aeroginosa was the most resistant one to steroidal and glycosides- steroidal Saponins with MIC of 500 and 400 micg/ml, respectively. Steroidal and glycosides- steroidal Saponins showed no bactericidal effect in gram negative bacterium Pseudomonas aeroginosa. Among the gram positive bacteria, the highest MBC of 500 micg/ml belonged to glycosides- steroidal Saponin for Staphylococcus aureus. The higher MIC in gram negative bacteria approves the lower antibacterial property of the steroidal and glycosides Saponin extracted from sea cucumber Stichopus hermanni in these bacteria compared to the gram positive ones.

Carbon and nitrogen sources are considering as the essential substances for microalgae growth. In this study the effects of sodium Nitrate (NaNO3) and sodium bicarbonate (NaHCO3) on the growth rate of N. oleoabundans microalgae in BBM culture medium were investigated. In this regards, different concentrations of NaNO3 as 0, 0.5. 1.0, 2.5, 5 and 10 and NaHCO3 as 0, 0.25, 0.5, 0.75, 1.0 and 1.25 in BBM during 21 days were tested. According to the results, by application of 10 mM NaNO3 the highest number of microalgae as (84.66±0.577)× 106 cells/mL was recorded and in case of nitrogen absence no increase in cell numbers was observed (p

In this research, the potential use of five hard parts (otolith, scale, eye lens, dorsal spine, vertebral bone) of Rutilus kutum for populations discrimination and biomonitoring as well as their usability as biological archive in the southern Caspian Sea was investigated. Two soft tissues (muscle and liver) were also analyzed for assessment of the possible risk of consumption and use as biomonitoring tool, respectively. A total of 60 specimens were collected using beach seine from three sampling sites (adjacent to the estuaries of the rivers Sefidrud, Tajan and Grorganrud, respectively) in the Southern Caspian Sea in May 2016. In total, the levels of 13 major and trace elements in the samples (the seven soft and hard tissues) was measured using PIXE (Proton Induced X-ray Emission) and µ-PIXE methods. Minor similarities among the tissues were observed in the case of eye lens (for P, S and Zn) and liver (for Cl, Fe and K). There were no significant relationships between the elements and biological characteristics (weight, total length and standard length). Based on the results, it seems that all the studied hard parts, except for eye lens, may offer alternatives for biomonitoring of Ca, Cl, Fe, K and S in the southern Caspian Sea. Considering Sr level in otolith, no significant differences could be found between the sampling sites 2 and 3. So it can be concluded that the specimens collected from the two sites are probably from the same population. Similar results were also obtained based on the results concerning K accumulation in scale. It can be concluded that scales may provide an alternative structure to otolith for stock discrimination of R. kutum in the southern Caspian Sea. Among the 10 elements that were detectable in the muscle using the PIXE method, only in the case of four of them (i.e. Zn, Cu, Fe and Mn) maximum allowable concentrations for human consumption have been defined, which in all the cases the mean concentrations in the present study were far below the recommended limits.

The present investigation was performed to identify the impact effect of development and climate change on the zooplankton assemblage in coastal waters of Bushehr-Delvar region. Sampling was occurred seasonally at depths of less than 10 m using a Bongonet (100 µm) at 10 stations including Jophreh, Jalali, Dastak, Saretol, Helileh, Bandargah, Niroogah, Bushehr, Piazy and Delvar from the summer 2015 to the spring 2016. 40 Zooplanktoon groups belong to 8 Phyla were identified. Crustaceans were the most dominant zooplankton group with the average annual abundance of 37.66% of total zooplankton abundance. The total annual abundance of jellyfish including Salps, Cnidaria and Ctenophora was 16.11% which in comparison with the previous registered data indicated a significant increase over the last four decades in the region. The average annual abundance of zooplankton and Shannon-wiener diversity index were 10577.5±5512.69 /m3 and 2.44±0.218, respectively. The highest and the lowest density of zooplankton were found in Saretol and Delvar stations with the average amounts of 21250±13874/m3 and 4388±3075/m3, respectively. Also, the highest and the lowest density and diversity of zooplankton were observed in the summer and the winter, respectively. Correlation coefficient between the average temperature variation with zooplankton density and Shannon–wiener diversity variations were assessed 0.665 (P

The present study focused on ontogeny of digestive enzymes activity namely Pepsin, Trypsin and Chymotrypsin of A. stellatus. Stellate larvae, from the first day of hatch to day 50 of development, were randomly taken for enzyme assay. Specific enzyme activities of Pepsin, Trypsin and Chymotrypsin were determined. The Peptic activity was detected in one-day-old larvae with a sharp raise of enzymatic activity from day 8 post hatch forth, especially during the larval transition to exogenous feedings (p

In this study, the concentrations of Cd, Pb, Cu, Mn, and Co were analyzed in the muscles of Cyprinus carpio collected from Nowshahr on the south of Caspian Sea, Iran in June 2016. Determination of heavy metals concentrations in the studied fish muscles had been carried out by a graphite furnace atomic absorption spectrometer. The range of metals concentrations were as: Cd: 0.10–1.56, Pb: 0.10–1.23, Cu: 0.88–8.23, Mn: 0.34–1.05 and Co: 0.56–1.43 mg/kg wet weight. The results showed that the concentrations of Cd, Pb, Cu, Mn, and Co in the muscles of C. carpio were lower than the proposed limits of the WHO. Health risks to human via dietary intake of fish were assessed by the target hazard quotients (THQs). The THQ values of the five metals (Cd, Pb, Cu, Mn and Co) were below 1 for C. carpio. Metal concentrations in the edible part of C. carpio were assessed for human uses according to provisional tolerable weekly intake (PTWI) and provisional tolerable daily intake (PTDI). In this study, Cd, Pb, Cu, Mn and Co concentrations in the muscle of C. carpio were below the maximum permissible limit of the WHO.

Malachite green is a very effective disinfectant that usually uses for fungal invasive and parasite treatments in fish, but is very dangerous for human health. The present study evaluated the existence of Malachite green in rainbow trout and common Carp, flesh. Eight treatments which included two mean weights (0.5 and 1 kg) at the four of (Haraz, Shahrekord, north of Iran and south of Iran) with triplicates were used. The fish flesh samples were taken from under dorsal fin. Malachite green was measured by ELISA method after sample preparation. Results showed that malachite green amounts in Rainbow trout of Shahrekord samples were 0.139 – 0.391 mg/kg and 0.367 – 0.477 mg/kg for 0.5 kg fish and 0.367 – 0.477 mg/kg for 1 kg fish. These amounts in Haraz zone fish were 0.468 – 0.680 and 0.281 – 0.529 mg/kg for 0.5 and 1 kg fish, respectively. There was no significant difference in Malachite green concentrations between 0.5 and 1 kg weights in each zone, but significant difference was observed between 0.5 kg fish from Haraz and 1 kg fish form Shahrekord zone (p0.05). The Malachite green amounts in Carp North of Iran samples were 0.32-0.48 mg/kg and 0.330-0.393 mg/kg for 0.5 kg fish and 0.329-0.484 mg/kg for 1 kg fish. These amounts in south of Iran zone fish were 0.29-0.41 and 0.318-0.414 mg/kg for 0.5 and 0.298 -0.334 for 1 kg fish, respectively. There was no significant difference in malachite green concentrations between 0.5 and 1 kg weights in each zone (p>0.05).

Shemaya (Alburnus chalcoides), Roach (Rutilus rutilus caspicus) and goldfish (Carassius auratus auratus) were belonging to the family Cyprinidae. The aim of this study was to observe the gastrointestinal tract of these fish. After the sampling, gastrointestinal tract and its accessory glands were taken and studied trough histological procedure using H&E staining. The age of the fish was 2 to 3 years old. Three examined species the digestive system was made up of esophagus and intestine and the accessory glands were liver and hepatopancreas around the intestine. Esophagus was short with small foldings compare to the intestine. The intestinal foldings were high and lanceolate in Roach, but round-tip in Shemaya and goldfish. The foldings have high density in anterior part of the intestine with minor differences between examined species. Goblet cells were observed in esophagus and intestine with higher density at posterior part of the intestine. Liver and hepatopancreas were close or apart from each other along the gastrointestinal tract. In conclusion, it has been observed that these three species has some common characteristics in digestive system structure with some species specific properties.

Aim of this study was determine of fatty acid profile, mineral and vitamins of Orange-spotted grouper (Epinephelus coioides) fried that deep frying with different plant oils (Corn oil, Grape seed oil and Olive oil). Highest and lowest contents of Orange-spotted grouper fillet was saturated fatty acids and polyunsaturated fatty acid, respectively. n-6 content of Orange-spotted grouper fillet with frying in Olive, Grape seed and Corn oil increased to 7.08, 24.30 and 41.59% respectively (p

In this study, the concentrations of heavy metals Cu, Fe and Se in muscle, liver and gill tissues of S. guttatus were evaluated in Bushehr seaport during autumn 2016. S. guttatus samples were caught at random from Bushehr seaport (n=30). After biometric measurements the samples were taken from each tissues (muscles, liver and gills) and chemical digestion of the samples were carried out based on MOOPAM, then levels of heavy metals in tissues were measured by Graphite furnace atomic absorption spectrophotometer (Perkin Elmer 3030). Based on the results obtained the mean concentrations of heavy metals Cu, Fe and Se in muscles tissues of S. guttatus were 7.21, 3.07 and 0.094, in liver were 8.35, 3.02 and 0.107, and in gill were 9.87, 3.59 and 0.119 mg/kg dry weight respectively. Moreover, this results revealed that the Cu and Se concentration in muscles tissues of S. guttatus in Bushehr seaport were lower than the levels permitted within the standards of World Health Organization (WHO), Food and Agricultural Organization (FAO), National Health and Medical Research Council (Australia) (NHMRC), Ministry of Agriculture, Forestry and Fisheries UK (MAFF), But Fe concentration was higher than the level permitted within the standard of Food and Drug Administration (FDA).

Despite the exploitation rate of Caspian Sea sturgeon stocks have been decreased for major national and regional reasons, catch decreased 78 times in the past century. At the moment, Iran's share compared to other Caspian Sea littoral country increased from 2.7% to 52%. But the annual growth rate of Iran's harvest 1.6% decreased. According to the documents, content analysis and statistical resources the structural system of the management governance of Iran sturgeon activities was studied in 4 historical periods (Since 1927 until 2014). Results demonstrated that structural changes, apportion of duties and incoherence of integrated activity in the sturgeon management especially in the last decade had a great effect on sturgeon stocks. In the latest period compared to the ideal period, the average of annual harvest decreased about 95%. Since the beginning of the present century, the annual average of caviar and sturgeon's meat harvest were about 146 and 1076 tons respectively. Based on the achieving strengths, weaknesses, threats and opportunities management, the present study recommended 3 scenarios as purpose to improve and change the governance structure of Iranian sturgeon activities and preserve this valuable fish. Results also showed that the value of heritage and preserve of sturgeon fish are higher than caviar's exploitation and their instrumental value.