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Efficiency of fishing gear used for king fish fishery with the emphasize on gill nets in Oman Sea- coastal waters of Sistan and Baluchestn ProvinceIranian Scientific Fisheries JournalEfficiency of various meshes of gillnets and trolling gear was investigated for catching kingfish (Scomberomorus commerson) in coastal waters of Sistan and Baluchestan province in 2007. In gillnets with mesh sizes between 57 to 110 mm and netting of monofilamnet and multifilament, the size distribution of kingfish ranged between 40 to 78 cm of fork length, which all specimen caught were immature. In mesh size of 146 mm and 171 mm, the length range of the species was larger, in which the frequency of immature fish for the respective mesh sizes was 19 and 11. In general, most fish was captured by wedging in the all mesh sizes. The size range of kingfish captured by the trolling was between 52 and 147 cm, of which more than 50 percent of caught fish were immature. The proportion of kingfish catches in the gillnets of 57-110 mm mesh sizes is about 13% of the total catch composition, for which the mesh sizes are considered as the dominant gillnets for capturing the species in this area. The conribution of kingfish catches in 133, 146, and 171 mm mesh sizes was 1.1, 52.3 and 18.9% respectively, with a 146-mm mesh size is considered as a dominant gillnet for this species. The implementation of the ban on the use of 57 to 110 mm mesh sizes for exploitation of kingfish is mandatory, which the mesh size of 146 mm and above seems to be appropriate for responsible fishery of the species. However, recommendation of standard mesh size needs to be re-examined in field trials.
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Effect of galacto oligosaccharide prebiotic on growth performance, survival and several of innate immunity parameters of rainbow trout (Oncorhynchus mykiss) larvaeIranian Scientific Fisheries JournalPrebiotics are non-digestive food ingredients which beneficially affect the host by selectively stimulating the growth and activity of health-promoting bacteria in the intestinal tract. This experiment was conducted to evaluate the effect of dietary supplementation of galactooilgosaccharide on the growth performances, survival and several of innate immunity parameters of rainbow trout (Oncorhynchus mykiss) larvae for 60 days. In this experiment, 360 of larvae (with average weight of 0.13±0.01g) in 4 treatments and 3 replicates (n=30 in each replicate) in a completely randomized design was divided and fed with diets containing 0, 1, 2 and 3 percent galactooligosaccharide respectively. The present results showed that highest WG, SGR and PER were observed in the diet containing 2 and 3 percent of dietary galactoologosaccharide which had a significant difference compared with other treatments (p<0.05). The highest, survival, total protein, albumin and globulin levels were observed in treatments containing 2 percent of dietary galactooligosaccharide which showed a significant difference compared with other treatments (p<0.05). Finally, the present results suggest that diets containing 2 percent of dietary galactooligosaccharide could improve growth, survival and innate immunity responses of rainbow trout.
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Study on meiobenthos abundance and their relationship with the condition of sediment in the northern creek of the Bushehr provinceIranian Scientific Fisheries JournalThe frequency and distribution of meiobenthoses in northern Creeks of the Bushehr Province during autumn2000- Summer200I were studied for determining the condition of sea sediments using seasonal sampling. Samplings were carried out in 10 stations from Doube Creek to Bandar Genaveh Creek as well as a control station in the Persian Gulf. Totally, 4 taxa of meiofauna were identified that Ostracoda and Gastropoda with 29% and 18% had the maximum and minimum percent of abundance, respectively. The maximum percent of abundance in station No.10(control station at sea) with 20735 n/m2 and the minimum abundance in station No.2 (Creek of Farake)with 5320 n/m2 were observed. The maximum abundance of meiobenthos in spring with 167603 n/m2 and the minimum abundance during winter with 61365 nlm2 were determined. In addition, grain size, soil texture and total organic matter (T.O.M) of sediment in 10 stations were analyzed. Results showed that station No.10 with 11.79% had the maximum percent of T.O.M while the minimum T.O.M (3.87%) in station No.4 (Gasir Creek) was observed. The correlation of sampling station based on the abundance of meiobenthos was also analyzed.
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Experimental study on histology of circumstance of wound healing process in common carp (Cyprinus carpio)Iranian Scientific Fisheries JournalThe present experimental research was carried out to study the histology the inflammatory response and circumstance of wound healing process in the inflicted skin and underlying muscle of common carp. A number of 30 fishes with average length of 22cm in a recirculating glass aquaria system, at an average temperature at 27°C, were used for this study. A surgical wound (1.5-2.0cm long x 0.5cm deep) without complication of secondary infections, was made by sterilized scalpel blade into the left dorsal muscle of each anaesthetized fish. At least one wounded fish was sacrificed and sampled at 30 minutes, I, 2, 4, 6, 8, 10, 12, 24 hours and thereafter at 2, 4,6, 8, 16, 24, 32, 40, 50 and 60 days after wounding. The samples were fixed in 10% buffered formalin and 5µ sections were prepared using standard histological method. The sections were stained by the standard H&E staining method. Also periodic acid schiff (PAS) with tartrazin were used for specific tissue features. The stained sections were examined using light microscope. Re-epithelialization of wounded epidermis was completed within 4 hours after wounding. Macrophage infiltration began at 2 hours, and myophagia at 6 hours. Fibroplasia and muscle regeneration were initiated at 2 days after wounding. After 16 days, epidermis was normal and dermis was completely linked. The wounded area restored its main components by 16 to 24 days after wounding. This study revealed that a healthy carp is able to have a rapid and effective inflammatory response and also high potential of repairing against surgical wound.
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Natural feeding of johns snapper (Lutjanus johnii) in the Persian Gulf (Hormuzgan Province waters) IranIranian Scientific Fisheries JournalSince a little information is available in relation with feeding of Lutjanus johni, this study was conducted to determine its food diversity. 613 specimens were studied from May 1996 to July 1997 and their dietary regim was defined. In this study, capacity vacuous index (CV) and food preference (Fp) calculated for this fish. The study of stomachs showed that stomach of 44 fish were full, 27 semifull and 524 were empty. CV was obtained 88.4 and Fp for crustacean (55.6), fishes (44.3) and molusca (1.4). In particularly study, Fp calculated for crab (54.0), squilla (23.2), shrimp (20.2) and lobster (2.5). Ultimately, in this survey was found that this fish possibly is fast feeder and crustacean to be omposed their main food. Among crustacean, crab is main food.
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Effects of different by catch reduction devices (BRDs) in shrimp trawlers in the Persian GulfIranian Scientific Fisheries JournalThe effect of different bycatch reduction devices in decreasing bycatch of commercial fish species with the length of less than LM50 (the length from which, 50% of them are matured) in shrimp trawlers were examined. The experiments were conducted in Persian Gulf (Bushehr and Hormuzgan provinces) during the shrimp season, years 2000-2001. In this study four types of bycatch reduction devices (Grid, Nafted, Fish eye and Square mesh window) were used. Double rig trawl was used, one of them as an experimental trawl and the other as the control. Different treatments like one device or two devices were installed on experimental shrimp net. After hauling the trawl, frquency of different commercial species with length less than LM50 was determined in both nets, and the results were tested with Paired Willcoxon test. The results have shown that although all the devices have a reductional effect on bycatch of the young and juveniles of commercial species, but the amount of reduction with setting Nafted and Grid, either single or combined with another BRD was significantly higher than the control one (P ≤ 0/05). The amount of by catch reduction devices with different treatment (different devices either single or paired) according to the season of the experiment were also tested with Kruskal- Wallis test, which shows significant differences (P≤0.05) between the frquency of young and juvenile individuals of some species during different experimental seasons. According to this study, by using Nafted and Grid devices in the trawl nets of all shrimp vessels during its season, about 400 to 500 thousand of juveniles and young individuals can escape from the nets.
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Identification of Jarahee river fishes in Kohguilouye & Boyerahmad and Khouzestan ProvincesIranian Scientific Fisheries JournalPrimary studies of this project began in winter 1996. After an experimental cruise, main sampling stations were determined and through six cruises the fishes of Jarahee river collected from headwaters in Khouzestan and Kohguilouye & Boyerahmad provinces to Shadegan lagoon. Through the 11 main stations, 1135 specimen of fishes were collected by castnet, gillnet, electroshocker, hoke & line and river-trawl. Collection process had conducted during May, June, August, September, November of 1997 and February of 1998. After one year laboratory studies, collected fishes were identified by some ichthyologic methods. Identified fishes (20 genus and 27 species) belong to nine families of Bagridae, Balitoridae, Cyprinidae, Heteropeneustidae, Mastacembelidae, Mugilidae, Poecilidae, Siluridae, and Sisoridae.
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Correlation of length and weight with mercury concentration in different tissues of Kutum Roach (Rutilus frisii kutum) in central south of Caspian SeaIranian Scientific Fisheries JournalWe used Mercury Analyzer to assess possible correlation between length and weight of the Kutum Roach (Rutilus frisii kutum) and mercury accumulation in different tissues of the fish. We collected fish specimens from central south Caspian Sea from October to December 2005. After biometrical measurement of samples and sex determination, mercury concentration was assessed in muscle, liver and skin tissues of the specimens. The mean concentration of mercury in muscle, liver and skin tissues was 849.9, 670.9 and 493.7ng/g respectively. Statistical analysis of the results showed a significant difference between mercury amounts in different tissues (P<0.05). No significant difference was found between male and female fishes in terms of mercury concentration (P>0.05). The mercury amount in muscle of Kutum Roach was lower than permissible limits proposed by FDA (1004ngig).
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Determination of maximum allowable concentration and LC50 96h of Sefidroud River sediments for Persian sturgeon (Acipenser persicus) fingerlingsIranian Scientific Fisheries JournalThe impact of Sefidroud River sediments on the fingerlings of Persian Sturgeon (Acipenser persicus) was studied in 2005. The tests were done in 20 liter aquariums each containing 10 Persian Sturgeons fingerlings weighing 3-5 grams each. We devised 6 treatments and a control with 3 repetitions in the four day investigation through which the lethal concentration (LC50 96h) of Sefidroud sediments were studied. During the test, physicochemical parameters of water such as pH, oxygen and temperature were measured as 8, 8.5mg/1 and 25±1°C respectively. The results showed that LC5096h and LC50 24h of sediments on Persian sturgeon were 15367.39mg/1 and 124882.04mg/1 respectively. We determined the maximum allow-able concentration (M.A.C) of sediments to be I 536.74mg/l .
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The effects of diazinon on haematological indices and LC50(96h) of Acipenser nudiventrisIranian Scientific Fisheries JournalWe treated 150 specimens of Acipenser nudiventris with diazinon and used 30 individuals as control to assess the haematological effects of the pesticide and LC50(96h) for the fish. The acute toxicity test lasting 96 hours was conducted on juvenile Acipenser nudiventris kept in aerated stagnant water contaminated with diazinon. The LC50(96h) values of diazinon for Acipenser nudiventris juveniles was 4.6 mg/i. The experimental groups of fish showed statistically significant difference in their erythrocyte, haemoglobine, leukocyte and differential leukocyte count (P<0.05). Acute toxicity effects of diazinon on the fish was recorded as lowered erythrocyte and lymphocyte count with a significant increase in developed neutrophile count (P<0.05). It is suggested that the change in erythrocyte and leukocyte count may have been caused as a result of disruption of haematopoiesis and a decrease in non-specific immunity level of the fish.
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Isolation and identification of Flavobacterium columnaris like organisms from grass carp (Ctenopharyngodon idella) and assessment of its histopathological effects in Khouzestan Province, Southern IranIranian Scientific Fisheries JournalFollowing a mortality of up to 40% of cultured Grass Carp (Ctenopharyngodon idella) in fish farms of Khouzestan province when water temperature was up to 20°C, samples were taken and examined for etiological clues. We observed that fish gills were coated with a gray-white mucus layer, fin was eroded and wounds were present in peduncle of the affected samples. Bacteriological studies on the samples of gills and eroded and wounded peduncle skin using Cytophaga selective medium, resulted in isolation of filamentous gram negative bacteria chemically similar to Flavobacterium columnaris. Histological observations showed the affected fish carrying symptoms including congestion, hemorrhagia, edema in base membrane, hyperplasia of chondrocyte and secondary lamellae cells, fusion of lamellae, necrosis and peeling of secondary lamellae and also presence of filamentous bacteria in gill tissue sections. Necrosis of skin layers and expansion of ulcer to underlying muscles, degeneration of muscle cells and necrosis of muscle bundles were seen in peduncle muscles. We did not find this bacterium in internal organs. We conclude that the isolation of the bacterium and observation of histo-pathological changes suggest the organisms may be considered as a primary or secondary factor in occurrence of the disease.
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Indentification of Babolrud River's fish faunaIranian Scientific Fisheries JournalThe objective of this survey, carried out from March to December 1994, was to study the composition of the fish fauna in Babolrud River, connected to the southern part of the Caspian Sea. The fishes were caught using a electroshocker device from 5 stations allocated to this purpose along the river. The obtained data from this survey indicated that the fish fauna of Babolrud River is comprised of 7 families. Family Cyprinidae with 15 species, including Capoeta capoeta and Carassius auratus, the two dominant species in the river, was the most abundant family compared to the other identified families (Balitoridae, Cobitidae, Gobiidae, Esocidae, Mugilidae and Petromyzontidae) represented only with one species each. The 67% of the fishes in Babolrud River are resident.
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Isolation of Aeromonas like bacteria from the grass carp (Ctenopharyngodon idella)Iranian Scientific Fisheries JournalIn 1993, 66 live Grass carps, Ctenopharyngodon idella, were transferred to the laboratory of the Fisheries Research Center in Khouzestan Province. 42 of them were apparently healthy and the remaining 24 had the following symptoms Dark body coloration on posterior region, petechia on the mandibula, operculum, abdomen and pelvic fins, loss of the scales, inflammation around the anus, eye hemorrhages, hemorrhages in the anterior chamber of the operculum, petechia on the muscles, swelled intestine, occasionally with yellowish - white mucus, fin rot, pale gills and liver. The microbiological investigation and bacteria culture from the gills, kidney and liver of the apparently healthy fishes and the diseased fishes showed that some of the fishes in both groups were infected by the Aeromons-like bacteria. Some specimens of this species were isolated from the internal organs (kidney and liver) and the gills. This study revealed that such organisms may cause mortality in the Grass carp farms.
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Identification of Plathycephalidae species in Bushehr Province waters (Persian Gulf)Iranian Scientific Fisheries JournalDuring the conducted cruises for implementation of projects entitling, "Studying Shrimp Nursery in Bushehr Esturies" and "Assessment of Bentic Stocks through Swept Area Method" in Iranian waters of the Persian Gulf, some samples of aquatics were collected. Among the collected samples the species belonging to Platycephalidae were identified in the region and are included: Platycephalus indicus, Grammoplites suppositus, Grammoplites scaber G. suppositus had more abundance than two other species (56%) and P. indicus had the largest size of total length.
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Study on some physicochemical parameters of the Oman Sea (I.R. IRAN)Iranian Scientific Fisheries JournalDuring executing stock assessment of Mesopelagic fishes project in the Iranian part of Oman Sea, some physicochemical parameters were studied surveyed area located between 22 ֯ , 44' - 25 ֯, 33' N Latitudes and 57 ֯ , 04' -61 ֯, 31' E Longitudes. Data collected in 3 months (June, Oct. 1993 and Feb. 1994) in this study, pH, Salinity, dissolved oxygen and water temperature measured from surface to 400 m depth. The results showed that thermal condition of this part of Oman Sea was stable in the warm months, and the seasonal thermocline occurred between 10-60 m depths. Amount of dissolved oxygen below 50 m depth regarding to it's minimum rate (1 mg/L) showed that the suitable circulation was not exist in this time of year, pH and Salinity had a little decrease from surface to depth but some stations showed variable salinity.
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Effect of rotifers enriched with betaine and concentrated diet containing betaine on growth, survival and stress resistance of Indian white prawn (Fenneropenaeus indicus)Iranian Scientific Fisheries JournalThis study was conducted to investigate the effects of rotifers enriched with betaine and concentrated diet containing betaine on growth performance, survival and resistance to salinity (10 and 5Oppt), temperature (42°C) and formalin (100ppm) stresses in Indian white prawn (Fenneropenaeus indicus) post-larvae. A complete randomized design with three replicates per treatment in nine 20-1 tanks was chosen. Treatments were: Artemia nauplii, rotifers and concentrated diet (control); Artemia nauplii, rotifers enriched with betaine and concentrated diet (treatment 1) and Artemia nauplii, rotifers enriched with betaine and concentrated diet containing betaine (0.8%) (treatment 2). The larvae were fed 6 times per day at 4h intervals. There were significant differences in growth and survival rate between the treatments containing betaine (treatment 1 and 2) and control treatment (P<0.05). Furthermore, the larvae that were fed with betaine (treatment 1 and 2) had significantly higher survival rate in stress resistance testes (P<0.05). The present study showed that betaine has positive effect on growth performance, survival rate and resistance to stresses in Indian white prawn.
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Quality control in Orange-spotted grouper, Epinephelus coioldes, during ice storageIranian Scientific Fisheries JournalIn this study, changes of TMA and its relation with bacteria count was evaluated in Orange-spotted grouper, Epinephelus coioides during ice storage at 18th day. TMA and bacteria count changes were evaluated at days 0, 3, 6, 9, 12, 15, and 18. TMA increased at days 0, 3 and 6 but changes during these days were not noticeable and it showed no significant differences (P>0.05). By passing time and from day 9 amount of TMA showed increased compared with other days and had significant difference in the value (P<0.05) such I that reached from 0.96 (day 0) to 12.46ms/100g (day 18). The psychrophilic bacteria showed a more monotonous change relative to the mesophilic bacteria and became dominant in ice through time. Logarithm of colonies of the psychrophilic bacteria per gram increased from 1.37 at day 0 to 7.72 at day I 8th. The mesophilic bacteria showed fluctuations in their number such that at day 15th they decreased and at day 18th, increased. The level of TMA showed significant difference between the first days and last days (P<0.05) such that they increased from 2 at day 0 to 4.61 at day 18th. Bacterial count especially *psychrophilic bacteria were increased during storage, whereas mesophilic bacteria decreased at day 15 of storage. TMA showed relationship with psychrophilic bacteria and storage days (P<0.05, R=0.98).
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Length frequency, length -weight relationship and gonad development status of silver pomfret, Pampus argenteus, in Khouzestan (Iran) and Kuwait coastal waters, Persian GulfIranian Scientific Fisheries JournalData used in this publication is a part of a comprehensive study was carried out jointly between South Aquaculture Research Center (SIARC) and Kuwait Institute for Scientific Research (KISR) on silver pomfret (Pampus argenteus) in 2003 to 2005. The study was aimed to collect efficient data from two regions from biological and population parameters of this economically important fish to properly explain its stock situation and ultimately leads to improve a better management program for conservation of stock and yield sustainability. Monthly data collection on length and biology, started since May 2003 and ended by December 2005. Shrimp trawl and gill nets were used for sample collection from the predicted areas in both sea regions. FL of the fish was within the range of 12-34cm, with the dominant length of 18-25cm in Kuwaiti waters. In Khouzestan waters fork length was ranged 14-22cm for the years of 2003 and 2004 but 14-26cm for 2005. Strong relationship between length and weight in both countries with a scanty difference was observed for this species (R2 =0.989 for Khouzestn, R^2=0.947 for Kuwait). The findings of present study are suggesting that silver pomfret is following an allometric growth pattern in studied area. Spawning of silver pomfert begin in July and continue till October in Kuwaiti waters but in Khouzestan waters the heights spawning of this fish started in end of May till October. Length at first maturity of this species in the studied area of Kuwait was found to be 19.6cm FL based on Spearman-Karber method but 23.3cm (FL) based on the logistic model. The parameter was estimated 20.0 cm (FL) in Khouzestan waters according to the logistic model.
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Determination of growth parameters, mortality and CPUE of Capoeta capoeta in Hassanloo reservoirIranian Scientific Fisheries JournalThe study was conducted to determine growth parameters, mortality, length frequency, age structure and catch per unit effort (CPUE) of Capeota capeota in Hassanloo reservoir in western Azerbaijan. Fish sampling was done seasonally in 2004-2005 by gill net with mesh sizes 20, 30, 40, 50, 60mm. The results showed age compositions of the fish were 1-5 years old. Average length and weight were estimated at 31.81±0.54cm and 601.30±20.49g, respectively. The range of total length and weight were 19-48cm and 120-1550g. The growth parameters were L.=53.086cm, t_o = -0.2898, K= 0.4120. Total mortality (Z), natural mortality (M) and fishing mortality (F) were 0.76, 0.58 and 0.18 per year, respectively. Growth in length and weight of Capoeta capoeta population in Hassanloo reservoir compared better than the same age fish in other ecosystems of the region. Average CPUE for 100m gill nets in 24 hours was estimated at 11.81kg.
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The effects of water quality on growth of the reared pacific white shrimp (Litopenaeus vannamei)Iranian Scientific Fisheries JournalWe investigated effects of water quality on growth of the Pacific white shrimp (Litopenaeus vannamei) reared in Heleh region of Bushehr in the south of Iran. Physico-chemical parameters such as water temperature, dissolved oxygen, salinity, pH and clarity were investigated in three 0.5ha shrimp ponds. Nutrients (nitrate, nitrite, ammonia and total phosphate), magnesium and sulphate as water quality factors were also investigated. Using one-way analysis of variance (ANOVA), a significant correlation (P<0.05) and inverse relationship were detected between water temperature and salinity with increase in length and weight of the shrimps. The morning pH values had no relationship with length and weight increase in the shrimps (P>0.05) while the afternoon pH values had negative significant correlation with the growth factors (P<0.05). Dissolved oxygen had positive significant correlation with the studied growth factors (P<0.05). Also, the total phosphate had negative significant correlation with length and weight growth of the shrimps (P<0.05) while nitrate had positive significant correlation with those growth factors (P<0.05). No significant correlation was found between the growth factors and other nutrients (P>0.05).
