Iranian Scientific Fisheries Journal
Year:2012 | Volume:21 | Issue:1 (78)|Papers Count:20

This study was conducted to assay the effects of different levels of dietary vitamins C and E on growth indices in Acipenser ruthenus in International Sturgeon Research Institute. Nine diets were supplemented with a combination of 0, 100 and 400mg/kg food vitamin C and 0, 100 and 400mg/kg food vitamin E and were fed to sterlets in 2 replicates during 15 weeks. Two hundreds and seventy sterlets with the average weight of 350.92±14.28g were introduced to 18 tanks (each tank 15 fish). The fish were fed with 3% of body weight per day. The results showed that the highest and the lowest weight gain were in fish fed with diet containing 400mg/kg vitamin C and 0mg/kg vitamin E, respectively. The highest and the lowest Feed Conversion Ratio (FCR) were measured in control and diet 100mg/kg vitamin C and 400mg/kg vitamin E. A significant difference was found in FCR between treatments. The lowest and the highest amounts of Growth Rate (GR), Specific Growth Rate (SGR), Body Weight Index (BWI), Food Efficiency (FE) and Protein Efficiency Ratio (PER) were found in control and treatment 100mg/kg vitamin C and 400mg/kg vitamin E, respectively. This difference was significant between the treatments. In conclusion vitamins C and E have an important role in enhancement of growth performance and feed efficiency of sterlet.

In this study, the effect of gelatin coating enriched with cinnamon oil for fresh fillet of rainbow trout on microbial were studied, chemical and sensory characteristics during storage at refrigerator condition. Fish fillet were treated in gelatin solution (4 percent) containing cinnamon oil and were stored in refrigerator. Total viable count was acceptable (7 log CFU/g) for coated fillets with gelatin coating containing cinnamon essential oil on day 15, but the control fillets also those that were covered with gelatin receipt to 7.88 and 7.44, respectively. In the tenth day. Psychrotrophic count values for the control and gelatin coated fillets significantly were increased more than other treatment. Total volatile bases nitrogen and Thiobarbituric acid values in gelatin with cinnamon coated fillet were less than other treatment. In general, results suggest successful inhibition microbial growth in refrigerated rainbow trout fillet is possible with gelatin incorporated cinnamon coating, as together they kept the sensory characteristics within acceptable limits throughout storage. Gelatin coating together with cinnamon oil provides a type of active coating that can be utilized as a safe preservative for fish under refrigerated storage.

As a part of a major ecological study of Hanna Wetland, Semirum Region, Isfahan Province, parasitic infestation of 3 native and one introduced fish species were investigated. A total of 120 fish specimens were collected by both cast net and a series of gillnets between fall and winter 2007, and spring and summer 2008. Some of the observed parasites are reported for the first time as new host records of: Trichodina perforata on gill and skin of Carassius auratus auratus and three species of leeches namely: Glossiphonia heteroclite, Thromyzon tessulatum and Hemiclepsis marginata on the skin and fin bases of Capoeta damascina. Moreover, 14 internal and external parasites including: one protozoan; Ichthyophthirius multifiliisand two myxosporeans; Myxobolus varicorhini, Myxobolus sp., three monogeneans; Dactylogyrus lenkoran, Dactylogyrus intermediusand Gyrodactylus sp., two immature digeneans; Diplostomum spathaceum, Tylodephys sp., two mature digeneans; Allocreadium isoporumand A. layman, one unknown cyst, one Acanthocephalan; Acanthocephalorhynchoidessp., one cestoda; Khawia armeniaca. The highest prevalence of Diplostomum spathaceum(100%) was observed in Aphanius isfahanensis and Alburnus sp. However, the lowest prevalence was related toA. layman in Capoeta damascina in winter (0%), and autumn and spring (11%). Leeches infection were only observed in Capoeta damascina and Alburnus sp. in winter and summer, respectively. The maximum average (±SD) infection intensity belonged toK. armeniaca in intestine of C. damascina in spring (12.50±3.40, range: 8-16). Among the parasites identified in the region, D. spathaceum showed the highest mean (±SD) abundance (41.67±11.79) in C. auratus auratus in spring. In general, a relatively high diversity of fish parasitic fauna exists in this water body which could jeopardize fish populations and the whole ecosystem if the ecological status of the Hanna Wetland is neglected.

The effect of garlic extract on growth and survival rates of one day larvae of Litopenaeus vannamei shrimp was tested for 12 days. Six nutritional treatments each with three replicates were fed to shrimp larvae (average weight 0.0013g) including control treatment (unriched Artemianauplii) and second to sixth Artemia nauplii enriched with 200, 400, 600, 800 and 1000mg garlic extract per kg, respectively. The one way ANOVA results showed that all treatments were different in terms of average weight and total length of larvae compared to control group. Shrimps being fed by Artesia enriched with 200mg garlic extract per kg food have the best growth, survival rates and length (0.0062mg, 81.6% and 10.6mm).Group 3 with concentration of 400mg garlic extract per kg of feed followed by control group showed better growth and survival rates in shrimp larvae than other treatments but the lowest survival rate evaluated in shrimps fed by Artemia nauplii enriched with 600, 800 and 1000mg garlic extract per kg feed, orderly. Specific growth rates (SGR) for treatment groups 2 and 3 were higher compared to other groups.

Recirculation water system in shrimp culture with objective of decline waste materials of culture media and decreasing the disease is one of strategy which helping the shrimp production. In this investigation, effects of different densities of Nile tilapia (Oreochromis niloticus) culture with white leg shrimp (Litopenaeus vannamei) on growth, nutrients conversion rate (nitrogen and phosphor) of shrimp biomass and production economy in recirculation system were studied. Economical efficiency obtained according to final harvested biomass (shrimp and tilapia), the price and other costs for each treatment. Experiments were done in tanks with 6 treatments including: Culture shrimp with exchanged water (T1), culture shrimp with recirculated water system (T2) and integrated culture of shrimp with different densities of tilapia (T3- 0.01, T4- 0.025, T5- 0.05 and T6- 0.075 shrimp- tilapia ratio). The density of shrimp in all treatments was constant about 40/m2. Shrimps were fed with commercial food pellet for 8 weeks. Tilapia was not fed during 7 weeks of experiment. Growth rate and total production of shrimp in T2 compared to that of T5 and T6 and results showed significant differences. No significant differences were detected with other treatments. Growth rate in T3 significantly increased compared to other treatments. Nitrogen conversion rate of biomass (tilapia and shrimp) in all treatments except T1 statistically demonstrated an increasing rate as the tilapia-shrimp ratio was increased. Phosphor conversion ratio of biomass (tilapia and shrimp) showed an increment in T3, T4, T5 and T6 and was significantly different with T1 and T2. Production economy in T2 followed by T4 was significantly increased compared with other treatments. The lowest economical efficiency obtained in T5 and T6 and the highest found in T2. The results of present study suggest that in integrated culture system (tilapia-shrimp), increasing tilapia densities may have a direct significance effect on phosphor conversion rate improvement and an inverse effect on nitrogen conversion and shrimp growth rates. Regarding to studied parameters, decreasing the tilapia- shrimp ratio (0.01 and 0.025) increased nitrogen conversion rate with no decrease in shrimp growth rate.

The present study investigated changes in growth and amino acid composition Kutum Rutilus frisii kutum during larval development. For this purpose, the periodic sampling from larvae obtained from breeders propagation was carried out at the fish aquaculture center of Shahid Rajaee in Sari. The samples were obtained at 1, 3, 7, 10, 15, 20, 25, 30, 35, 40 and 50 days after hatching (DAH). The result of larvae growth showed that mean initial and final length of Kutum (1 DAH, 50 DAH) were 8.47±0.02mm and 35.34±0.41mm, respectively. Initial and final weights were 4.02±0.01mg and 483.33±1.11mg, respectively. The composition of total amino acids of Kutum larvae changed significantly during ontogeny. High correlations were found between rotifers and dry food but correlations dry food was higher than that rotifer. No major imbalance was found in essential amino acids profile of the diet of fish larvae. Nevertheless, low correlation of rotifer to dry food in rotifer AA nutritional balances was less than dry food. During this study, methionine, lysine, arginine, threonine and histidine appeared to be limiting amino acids. These fatty acids showed the significant difference between the amino acid profile in larva and the diet.

Previous studies showed that the level of mercury in Sanandaj Gheshlagh Reservoir (SGR) was higher than limits established by the World Health Organization. Total Mercury (T-Hg) concentrations in white muscle, red muscle and liver tissues of Common carp as the most consumed fish in the region were investigated. For the first time the content of mercury in red muscle tissue was measured and compared with white muscle and liver tissues. During the July to December 2009, 24 Common carp were caught from SGR (4 samples per month). THg concentrations in above mentioned tissues were measured, using Mercury Analyzer. T-Hg concentrations variations in white muscle, red muscle and liver tissues were (123-458), (115- 455) and (107-303) ng g-1, respectively. Statically significant differences were found between three tissues. A significant monthly variations of T-Hg concentrations were observed within liver tissue samples. Fish weights in this ranged between 330.1 to 753 grams. T-Hg in white and red muscle tissues in all samples weighted above 500 grams were higher than the limits established by the EPA. Therefore, additional researches are needed to evaluate any potential effluence of this fish consumption on people health.

The aim of this research was to study the effect of astaxanthin pigment on growth performance (weight again, specific growth rate and final body weight), survival and pigment accumulation in postlarvae of white leg shrimp. This study was carried out in spring 2011 at Kolahi Aquatic Development Center. Some 8-day postlarvae with mean (±SD) initial weight 5.3±1.6mg were fed diets with containing various levels (0, 50, 100 and 200mg/kg diet) of astaxanthin pigment for 30 days. Shrimp fed with diet without astaxanthin pigment served as control. Shrimp fed diets containing 50, 100 and 200 mg/kg astaxanthin, growth performance and survival was significantly higher than control group. The pigment accumulation rate was determined by high performance liquid chromatography (HPLC). The analysis of pigment accumulation showed that the higher increasing astaxanthin pigment amount in the diets, the higher growth performance and survival rate in postlarvae; as in postlarvae fed with 200 mg astaxanthin/kg, final weight (700.6±12.7mg) and survival rate (82±1.5%) was significantly higher than control group (484.2±28.9, 54.7±4.5% final weight and survival rate, respectively). Due to nutritional properties of astaxanthin pigment and the positive effect on growth and survival, the feeding of postlarval white leg shrimp with the diet containing at least 100 mg astaxanthin/kg is recommended.

The aim of this study was to determine proximate composition and the profile of amino acids in the bones of three pelagic fish including: Gold stripe sardine (sardinella gibossa), anchovy kilka (Clupeonella engrauliformis) and Indian anchovy (Stolephorus indicus). Proximate composition of the bones showed maximum moisture and protein in the Indian anchovy. Maximum content of lipid and ash and highest ratio of ash/protein in the dry matter whiteout lipid was found in anchovy kilka. The amino acid composition of the bones was determined on a dry weight basis. The total essential amino acids showed no significant difference between anchovy kilka and gold stripe sardine but showed different levels of essential amino acids to that of Indian anchovy. Total non essential amino acids in anchovy kilka and Indian anchovy were not significance but gold stripe sardine had the minimum content. Highest amount of total sulfur amino acids was found in the anchovy kilka. The amino acid score showed that three species have good essential amino acid for the growth of the human recommended by FAO/WHO. The predicted protein efficiency ratio shows that the quality of protein was high. Chemical composition of three species had a good nutritional value but some parameters were lower than the human needs. The best chemical composition observed in the gold stripe sardine. It is seems that bones powder of these kind of fish may be used as ingredient in the food industries.

This study investigates the effects of prebiotic oligofructose on some growth factors, survival, body composition and resistance to salinity stress of Caspian Roach (Rutilus rutilus) fry. Fries with average (±SD) weight of O.06±O.03g supplied form Sijowal Center, Golestan Province and were randomly allocated in 12 tanks and after acclimation, triplicate groups were fed with diets supplemented with 0 (control), 1, 2 and 3% prebiotic oligofructose. At the end of the trial growth factors (final weight, weight gain, SGR, CF) as well as survival rate, body composition (crude protein, lipid, ash and moisture) and resistance to salinity stress were measured. Our results showed that roach fries fed with prebiotics supplemented diet had better growth condition include final weight, specific growth rate, condition factor compare to control treatment. Caspian roach fed with 2% oligofructose had significantly higher final weight, SGR, CF compare to control and 1% oligofructose treatments. Weight gain showed no significant difference between prebiotic supplemented treatment. The study of body composition showed no significant difference between treatments groups. Roach fries fed with prebiotic supplemented diet had significantly higher resistance to salinity stress and highest survival observed in 3% oligofructose treatment.

One of the essential factors in zooplankton culture is dissolved oxygen (DO), especially copepods. This is because of DO effects on their growth and reproductive parameters. Effects of different DO concentrations on growth and production of cyclopoid copepod Metacyclops gracilis fed on green algae Scenedesmus quadricauda were investigated in laboratory conditions. Experiment treatments were 2, 3, 4, and 6mg/l of DO. Results showed that mean total production (nauplii+copepodids+adults) of M. gracilis were 3666.7, 3133.3, 3600.0 and 3733.3ind./1 at 2, 3, 4, and 6mg/1 DO, respectively. While total nauplii production was 1533.3, 2000.0, 2466.7 and 2800.0ind./l, and copepodids were 1266.7, 666.7, 600.0, and 600.0ind./l, respectively. The specific growth rates (SGR) of M. gracilis were 0.088, 0.082, 0.061 and 0.081/day at 2, 3, 4, and 6mg/1 DO, respectively. This study showed that M. gracilis can grow and produce at different concentrations of DO, but at 4 and 6mg/1 DO nauplii stage and at 2 and 3mg/1 DO adults stage significantly increased in population. This species could be used as live food for fish larval rearing in aquaculture industry.

Considering the effects of dietary nucleotides on growth and metabolism, this study was conducted to determine the effect of different levels of this nutrient on the sources of the body needed energy, and growth performance of common carp. Fish with average (±SD) weight of 7.5±0.2g were fed to five levels of dietary nucleotides containing 0, 0.1, 0.2, 0.3 and 0.4 percent for 8 weeks. Fish were fed 5 times daily according the satiation. After 56 days, the results showed that the level 0.2% nucleotide had the highest growth rate in terms of weight and length, but other parameters such as body weight, specific growth rate and feed conversion ratio, differences were not significantly changed. Biochemical analysis of serum parameters and proximate analysis showed that the physiological function of fish affected by different levels of nucleotides whereas in the energy supply sources, including glucose, triacyleglycerol, total protein and albumin there were no significant difference in cholesterol and lipid content of carcass. This study conveys a positive effect on the biosynthesis of dietary nucleotides on energy sources and growth functions, while the common carp has ability to synthesize this substance into the body, the level of 0.2% in the diet can affection sufficient effect on growth and some biochemical indices.

In this research, concentrations of heavy metals (i.e., cadmium, lead, copper) in muscle, liver and gill tissues of Euryglossa orientalis (Family: Soleidae) in two fishing areas, from northern Persian Gulf that names Hendijan port (Bahrekan) in Khuzestan province and Deylam port in Bushehr province were measured and compared. Fifty fish samples randomly were collected from Hendijan and Deylam ports each from 3 stations, in summer 2008. Tissue samples were digested using MOOPAM method and metal concentrations (Cd, Pb, Cu) were measured using atomic absorption spectrophotometer (AAS). Cadmium, lead and copper concentrations were varied significantly among gills, liver and muscle tissues of fish samples in any area from Hendijan and Deylam. In Hendijan area higher mean (±SD) concentrations of cadmium and copper were observed in the liver (2.11±0.22 and 366.41±15.63 mg/g, respectively. Lower concentrations in the muscle (0.70±0.07 and 5.08±0.27 mg/g respectively. In Deylam area higher mean (±SD) concentrations of cadmium and copper were observed in the liver (1.47±0.10 and 240.24±10.50 mg/g, respectively lower concentrations in the muscle (0.49±0.07 and 3.08±0.52μg/g), respectively. In Hendijan area higher concentration with mean (±SD) of lead was observed in the gill (10.72±1.71 mg/g with lower concentration was noted in the muscle (5.20±0.05 mg/g) of fish. In Deylam area higher mean (±SD) concentration of lead was observed in the gill (6.91±0.52 mg/g) with lower concentration in the muscle (4.09±0.52 mg/g). In general, our study showed that concentration of heavy metals in different tissues of fish in Hendijan area was significantly higher than Deylam area. Also, cadmium and lead concentrations in muscle tissue of Euryglossa orientalis in both sampling area were higher than the acceptable limits reported by WHO, FAO, ITS and others.

Fixed gill net has been used for Teleostei fishery by the fishermen in Anzali Wetland. The aim of this study was to compare the CPUE, species composition, length frequency and the vulnerability of Teleostei between fixed gill net and fyke net from 1st November 2010 to 30st March 2011 in Anzali Wetland. Ten fixed gill nets and ten fyke nets were set. Mean CPUE (±SE) was estimated 0.17±0.03 and 0.26±0.07Kg/24h for fixed gill net and fyke net, respectively. Mean CPUE differed significantly between two gears. Also mean CPUE (±SE) differed significantly between fixed gill net and fyke net for 100m2 with higher CPUE (2.14±0.54Kg/24h) in fyke net. The relative frequency of caught species in fixed gill net and fyke net were dominated by Carassius auratus (38%) followed by Esox lucius (65%), respectively. Length-frequency distributions of the species had greater range of length and weight in fyke net in relative to fixed gill net. The amount of damage differed significantly between fixed gill net and fyke net with less damage and with higher survival in fyke net. The results of this study showed that fyke net has valuable and marketability catch in relative to gill net that resulted to higher income for fishermen. Also these results demonstrated that fyke net had less pressure on environment of Anzali Wetland.

Gastropod communities were investigated along two intertidal sandy and rocky shores in Qeshm Island, the northern Persian Gulf, IR Iran to identify the species of the family Cypraeidae. Monthly sampling was undertaken from May 2007 to April 2008 by haphazardly placing eighteen 0.25 m2 quadrates along two 30m wide transects located approximately 300m apart, perpendicular to the sea, in each sandy and rocky shore. Four species and subspecies belonging to the family Cypraeidae were identified including Cypraea feline fabula, Cypraea grayana, Cypraea nebrites and Cypraea turdus winckworthi. All species occured on rocky shores. Identifications were verified by Dr. Robert G. Moolenbeek, from Natural History Museum of Amsterdam, The Netherlands.

The aim of this research was to identify and isolate the fatty acids composition of Nerita textilesin intertidal area of Chabahar Bay, and also to explore the seasonal changes of fatty acid content in Nerita textiles. GC/MS resulted thirteen fatty acids, that saturated fatty acids (SFA) of palmitic acid (16: 0) was the most abundant category of fatty acid obtained in total lipids. There were no significant differences in total saturated fatty acids between different seasons. No significant differences were also observed in total unsaturated fatty acids between different seasons. The majority of unsaturated fatty acid reached their maximum levels during winter, while saturated acids reached their maximum levels in summer. Saturated acids were more than unsaturated fatty acids. Statistical analysis showed the positive significant correlation between temperature and saturated fatty acids and a negative significant correlation between temperature and unsaturated fatty acids. Biomarker fatty acids revealed that diet of Nerita textiles probably includes phytoplankton, zooplankton, detritus, bacteria, diatoms, red and brown algae. The results showed that meat quality indicated n-6/n-3 ratio in the range of 1.9 to 4.3.