NEW TECHNOLOGIES IN AQUACULTURE DEVELOPMENT (JOURNAL OF FISHERIES)
Year:2012 | Volume:6 | Issue:1 (21)|Papers Count:20

This study investigated food chains and fishes feeding habits in Laar Reservoir ecosystem. It investigated monthly hydro-biological parameters such as density and distribution of zooplankton, animal macro-benthic and fish in 12 different sampling stages from June until November in 2008 and 2009. Zooplankton sampling has been done vertically using with Juddy Net, macrobentic using with Grab (400 cm2), Surber (1600 cm2 and hand net (2500 cm2) and fishes were caught using with Cast net, Electro-Shocker in near to Dam and Emam-Pahnak (Delichai), Ab-Sefid, Elarm and Kamardasht tributaries stations. This study showed there were 21 genera and species belong to 3 Zooplankton orders in Laar reservoir which Cladocera order was dominant and it constituted about 55.81% of zooplankton population in all studied period.The highest cell density of zooplankton associated with the Orders of Cladocera (48050±0.05 number/m2) and Rotatoria (24020±0.02 number/m2) in June. There were 98 genera and species in 12 orders of macrobenthic and Diptera order with abundance of 676 number/m2 and biomass of 1.79 gr/m2 in 2008 and 767 number/m2 and biomass of 2.50 gr/m2 in 2009 was dominant.There were 5 fish species which Salmo trutta fario constituted more than 95 percent of caught fish population and the averages of its weight and fork length were measured 136.86±103.4 g and 212.81±49.6 mm, respectively. The two-way ANOVA showed that sampling months and studied stations affect fauna abundance (P<0.05). Biological studies indicated that this reservoir has low potential to planktonic productivity and due to geographical location of this dam, remarkable temperature differences can be observed in different years especially in fall and winter, which is biologically important. In the study, we record many species of zooplankton and animal macrobentic for the first time from Iran.

This study was conducted to determine the different levels of dietary vitamin C and vitamin E on WBC fluctuations of sterlet (Acipenser ruthenus) in Dr. Dadman International Sturgeon Research Institute. Nine diets supplemented with a combination of 0, 100 and 400 mg/kg vitamin C, L-ascorbyl-2-polyphosphate (APP), and 0, 100 and 400 mg/kg vitamin E, D-alphatocopherol, were fed to sterlet in 2 replicates for 15 weeks. Fifteen fish with the average weight of 350.92±14.28 were distributed to each of 18 tanks after adaptation with experimental diet.The fish were fed 3% of body weight per day. Blood samples were obtained from three fish of each tank at the end of the experiment. The results of blood samples at the end of 15th week revealed a significant difference between WBC and monocytes, lymphocytes and neutrophils (P<0.05).The highest and the lowest WBC count was observed in fish fed with diets containing 100 mg kg1- vitamin E and 400 mg kg1- vitamin C (diet 6) and fish fed with 400 mg kg1- vitamin E and 400 mg kg1- vitamin C (diet 9), respectively. Also, the highest monocytes, lymphocytes and neutrophils were observed in fish fed with diets containing 0 mg kg1- vitamin E and 0 mg kg1- vitamin C (diet 1), 0 mg kg1- vitamin E and 100 mg kg1- vitamin C (diet 2) and 400 mg kg1- vitamin E and 400 mg kg1- vitamin C (diet 9), respectively. On the other hand, the lowest monocytes, lymphocytes and neutrophils were observed in fish fed with diets containing 100 mg kg1- vitamin E and 0 mg kg1- vitamin C (diet 4), 400 mg kg1- vitamin E and 400 mg kg1- vitamin C (diet 9) and 0 mg kg1- vitamin E and 100 mg kg1- vitamin C (diet 2), respectively.

Artificial breeding can be considered as one of the methods to preserve sturgeon species stock. In this regard, improving incubation system is of a great significance. Azarakhsh and Shilaneh incubators were designed and constructed by Iranian experts in 2005 and 2009, respectively. In order to compare efficiency of Azarakhsh, Shilaneh, and Youshchenko incubators, some growth and development stages parameters of obtained embryos and larvae from an Iranian sturgeon breeder was studied. The results indicated that Azarakhsh incubator is preferable to Shilaneh and Yushchenko incubators in terms of fertilization percentage in blastula (86.73, 72.20, and 52.66, respectively), fertilization percentage in Gastrula (75.86, 60.16, and 41.50, respectively), loss percentage of incubation period (11.44, 26.21, and 35.06, respectively), hatching percentage (88.55, 73.79, and 64.94, respectively), and final survival (82, 80, and 75.66, respectively). Also, final length (27.31, 27.75, and 26.66mm, respectively) and final weight (123.00, 133.80, and 107.53mg, respectively) of larva in Shilaneh incubator were higher than those of Azarakhsh and Yushchenko incubators. Azarakhsh incubator can be concluded to be more efficient than Shilaneh and Yushchenko incubators.

Kutum (Rutilus frisii kutum) is one of the most important fishes of the Caspian Sea which migrates annually to Iranian rivers such as Shirood River. In this research mutual effects of age have been analyzed on some sperm parameters (volume, density, spermatocrit and motility percent) of kutum (Rutilus frisii kutum) and the artificial propagation in Shirood River. For this reason acquired sperm from 30 male broods (2, 3, 4, 5 and 6 years old) were combined with ova of 30 females. Maximum weight (975 g) and total length (47.25 cm) were related to 6-year-old male broods, while minimum weight (373.33 g) and total length (35.67 cm) have been observed in 2-year-old male broods. The highest sperm volume (5.22 ml), spermatozoa density (45´109 n/ml), spermatoicrit (39.3%) and spermatozoa motility (77.4%) were related to 5, 2, 2 and 4 years old stocks, respectively. In other hand the least sperm volume (3.03 ml), spermatozoa density (30´109 n/ml), spermatoicrit (30.3%) and spermatozoa motility (74%) were related to 2, 6, 4 and 6 years old stocks, respectively. A peak percentage of fertilization (95.2%) and hatching (83%) occurred in 4-year-old, while a minimum percentage of fertilization (88.5%) and hatching (77.6%) were showed for 6 and 2 years old stocks. Statistically there were not any significant differences between different ages as sperm volume (P=0.323), spermatozoa density (P=0.539), spermatoicrit (P=0.187) spermatozoa motility (P=0.164), but fertilization percent average did not indicate significant differences between different ages groups (P=0.016). So4 years old male brood stocks are economically the best choice for artificial propagation.

The phytoplankton, zooplankton, Macrobenthos and ctenophore Mnemiopsis leidyi with Physico-chemical parameters and pollutants of water were investigated in the Caspian Sea during 2007-2008. The sample station was located between 48o to 54o longitude and 36o to 39o latitude. The samples were gathered in four seasons and eight transects (half-line perpendicular to the coast) in Astara, Anzali, Sefidrud, Tonekabon, Noshahr, Babolsar, Amirabad and Turkmen. Sampling was done of 5, 10, 20, 50 and 100 M depth of different layers.Nonparametric test and multivariate analysis (PCA) were run. The results showed that some water physico-chemical factors including organic nitrogen, inorganic nitrogen (ammonium), salinity, water temperature were more important than other factors. Also, the abundance and biomass of M. leidyi depended on water temperature and nitrogen compounds, which has resulted in a change in abundance, biomass and species composition of marine plankton.

In this research, we investigated lead effects on hematological parameters (R.B.C, Hct, Hb, M.C.V, M.C.H and WBC, Lymphocyte, Monocyte, Neotrophile, Basophile, Eosinophile) of Juveniles of Acipenser persicus exposed to lethal lead concentrations (LC50) and two sub lethal lead concentrations after 96h. Preliminary series of short-term static acute toxicity tests were run to determine the median lethal concentration (LC50) of lead “Pb (No3) 2” for Acipenser persicus, according to the O.E.C.D method at the Caspian Sea Ecology Institute in 2008. Juveniles of mean mass: 30-35 g were obtained from the Shahid Beheshti hatchery station. Experiments were performed in tanks containing 10 fish. The test consisted of 9 group of 10 fishes each exposed to one of the following lead concentrations: 0 (control), 883.4, 900, 916.7, 933.4, 950, 966.7, 983.4, 1000 mg Pb.L-1. Mortality and abnormal behavioral response were recorded every 24h, during 96h.The short-term lethality test gave 96h LC50 of 944.118 mg Pb.L-1. The physico-chemical parameters of the Tajan river water were as follows: dissolved oxygen 8.3 mg/L, water temperature 8±1oC, pH: 7.65, water hardness: 370 mg/L caco3. In order to evaluate lead effects, fish were exposed to two sub lethal lead nitrate concentrations corresponding to 25% and 75% of the LC50 (96h) and lethal lead concentrations (LC50). Therefore, lead concentrations tested in the sub lethal and lethal experiments were 236 and 708.088 and 944.118 mg.L-1. For each lead 6 fish held in water and 3 fish were sampled after 96h. Control group consisted of 6 animals exposed only to water, without lead, sampled after 96h.Acipenser persicus in 236 ppm showed significant increase in erythrocytes count, no significant increase in hemoglobin, hematocrit percent, MCV, MCH and in 708.088 ppm showed no significant decrease in erythrocytes count and no significant increase in hemoglobin, hematocrit percent and significant increase in MCV and MCH.Acipenser persicusin 944.118 ppm showed a significant decrease in erythrocytes count, hemoglobin, hematocrit percent and no significant increase in MCV and MCH. Total WBC count, monocytes, basophiles showed no significant increase and lymphocytes and eosinophile showed a no significant decrease in all treatments. Neotrophiles in fishes exposed to the 236 ppm showed no change but showed no significant increase in 708.088 and 944.118 ppm.

This study was carried out with the aim of induction of pikeperch (Sander lucioperca) using various hormones. For this reason, fish were injected under four hormonal treatments, so that each group of four broods were injected in two doses with pituitary hormone extract (1.5 and 4.5 mg/kg), LHRHa2 (3.5 and 10 mg/kg), hCG (150 and 500 IU/kg), and saline (control). The results showed that all male and wild females responded to pituitary extract and LHRHa2, while in wild female which injected with hCG and farmed females which injected with hCG and pituitary extract, 75 percent responded to hormone therapy and no farmed fish responded to LHRHa2. According to reproductive parameters with the parameters including the number of eggs and working fecundity, no significant difference was observed in different treatments.Considering the obtained results from this study it seems that pituitary extract and hCG have a high performance and was recommend induction of artificial reproduction in Pikeperch.

This investigation was conducted to determine optimal light intensity of continuous photoperiod (24L/0D) at Research Station of aquatics nutrition and live food, located at Bandar Anzali in 2008-2009 for 60 days. The trial was carried out in 12 fiberglass tanks with a water volume of 80L, with flow rate of 0.8 l/min, and fish stocked at rate of 20 fish/tank with average initial weight of 12-13 gr. The design of the experiment consisted of 4 treatments with triplicates which included light intensity 100 Lx, 200 Lx, 300 Lx, 400 Lx. The experimental fish fed on commercial food of FFT and GFT for the weight groups of 12-30, 30-50 gr respectively.The statistical analysis indicated that with increasing of light intensity growth rate increased from 100 Lx to 400 Lx but the Weight gain (%), Specific growth rate, Food conversion ratio, Condition factor and Survival (%) were not significantly different among all treatments (P>0.05). The statistical analysis did not show significant difference among all treatments. The results of this experiment showed that the best growth rate and optimal food conversion ratio was obtained from light intensity 300-400.

This study was conducted to evaluate diazinon pesticide impact on some hematological indices in rainbow trout fry in Dr. Keyvan, s Research Center for Fisheries Sciences & Marine Technology (Islamic Azad University, Lahijan branch, Chamkhale port). During one week 120 pieces rainbow trout fry were exposed to three different consentration of Diazinon including 25, 50 and 75 percent of its LC50 (LC50=1.65 mg/lit) in 3 experimental groups and one blank group (by three times replicates) by O.E.C.D method. Exposed fry fishes showed some signs including neural paralysis, imbalance, abnormal swimming, severe impatience and paleness. The result showed that the number of leukocytes, erythrocytes, haematocrit and hemoglobin significantly decreased (P<0.05), but the amount of MCV and MCH increased significantly by 50% and decreased again, lymphocyte increased significantly by 50% and then increased by 75%.Resulted changes in erythrocyte & leukocytes after exposing with diazinon is due to malfunction in hemopoiesis and decrease in non-specific immune system.

The research project of monitoring of demersal resources by swept area method in the Oman Sea was carried out by Ferdows trawler in summer and fall, 1999. Two research cruises were condunted by R/V Ferdows.The studied area was from Meidani (58o 55’ E) to Gwatre Bay (61o30’ E). This area from eastern to western area was divided in to 5 sub regions (A, B, C, D and E) each covering 30 minutes. In each cruise, sampling was carried out for more than 65 stations using a bottom trawler. The calculated annual biomass for the whole area was 41830.3 tons in 1999. The amount of biomass in summer and fall was 44170.6 and 39490 tons, respectively. Also the calculated annual biomass for Parastromateus niger, Scomberoides commersonianus, Nemipterus japanicus, Pomadasys kaakan and Otolithes ruber were 337.7, 804.5, 1115.3, 949 and 877.6 tons, respectively. The results indicated that these species in forms large schools were observed at the depth 10-20 m in the summer.

Marzanabad pond is located in Mazandaran province, south-western part of Babol. Its area is 183 hectar and its mean depth is 2.5 meter. This pond is rich in aquatic plants and has been a good habitat for migratory birds. Entrance of farmland wastewaters and pollutants are from the impacts leading to a loading of DIN and TP into this pond. This study was conducted in order to investigate trophic status in this ecosystem for the first time during 1 year since September 2006 to August 2007. In this research, water temperature, dissolved oxygen, pH, trophic state indicators including TP, Chla, Secchi depth and dissolved Nitrate concentration were studied based on the Carlson trophic state index in 3 stations with 3 replicates monthly. According to TSI, Marzanabad pond is in eu-hypereutrophic condition.

Nowadays dietary supplements such as immunostimulants and prebiotics are being applied as a potential replacement of antibiotics in preferment of health and creation resistance against diseases in aquaculture. This survey was conducted to evaluate the efficiency of commercial prebiotic Immunogen with main ingredients 30% (1, 3-1, 6) ßglucan and 18% mannanoligosaccharide in ration of great sturgeon (Huso huso) juveniles in 8weeks in Shahid Marjani Sturgeon Propagation and Rearing Center in summer 2009. Hematological and immunological indices of great sturgeon juveniles in five treatments (0, 0.5%, 1%, 2% and 4%) of Immunogen in diet statistically compared. Three weight groups of great sturgeon juveniles with average weight 8.71±0.02 g, 25.15±0.01 g and 53.69±0.02 g were stocked in tanks and fed six times a day. The results showed the number of neutrophil in fishes fed with the diet supplemented with 0.5%, 1% and 4% Immunogen was significantly higher (P<0.05) than the control. Level of immunoglobulin M (IgM) in fishes fed with the diet supplemented with 0.5% Immunogen was higher than the other diet treatments. No significant difference was observed in other hematological indices between three weight of treatments and five treatments of Immunogen (P>0.05). It seemed that Immunogen in concentration 0.5% can serve as functional feedstuffs in the diet of great sturgeon juveniles by stimulating immunity responses.

To identify and investigate the biological characteristics of Neogobius melanostomus this research was done. For this purpose, 5 sampling sites (Astara, Anzali, Kiashahr, Hashtpar and Chaboksar) were selected in coastal area of the Guilan Provinc. Bottom traveling was used for the sampling of N. melanostomus.7.43% of total caught Gubiidae was related to N. melanostomus.The fish population was 4.54% in Astara, 5.97% in Hashtpar, 7.41% in Anzali, 1.28% in Kiashahr and 20.51% in Chaboksar. Based on the results of this study, mean of total length was 106.03±15.7 mm and mean of total weight was 12.54±2.57 gr. Age composition of the samples were in 3 age groups, 1-3 years old, with the age groups 2-3 years old being dominant (64%).Food items of this species based on the gut content were from benthic species such as Balanus, Hypanis, Gammaridae, Cumacae and Mytilaster. Based on these results, mean of feeding rate (747.12±19.2) and relative gut length (0.99±0.03) were highest in the 0+ year old class, and these parameters were lowest in the 3+ year old class. The maximum (6.42±0.62) and the minimum (1.05±0.2) of condition factor was in the 3+ and 2+ years old class, respectively. Mean of egg diameter was measured 1.53±0.3 mm. Average absolute fecundity and relative fecundity was calculated 610±202 eggs and 66.35±13.91, respectively.

The aim of the investigation of Anzali's wetland pike was to study infections condition in Anzali's wetland pike as well as determination of outbreak amount, severity of infection, abundance and index of parasitic prevalence. Fish were studied after bioassay according to common methods of necropsy during of 1 year from the fall of 2010 to the summer of 2011. In this study 10 species parasites were recognized, including two species of Crustaceae (Argulus foliaceusand Lernaea cyprinicea), two species of Nematoda (Eustrongylides exises and Raphidascaris acus), two species of Monogenea termatoda (Tetraonchus monenteron and Dactylogyrus sp), one species of Digenea termatoda (Diplostomum spathaceum), one species of Unicellular (Tricodina sp), one species of Acanthocephala (Corynosoma strumosum) and one species of Plathyhelminthes (Rhipdocotyle illense) isolated from the wetland pike. According to results, highest incidence (26.66%) was due to Eustrongylides exises and Lowest incidence (3.33%) was due toTricodina sp, maximum average virulence (88.5 pieces) was due to Rhipdocotyle illenseand minimum average virulence (1.75 pieces) was due to Lernaea cyprinicea, maximum average frequency (11.8 pieces) was due to Rhipdocotyle illense and minimum average frequency (0.09 pieces) was due toArgulus foliaceus, maximum parasite number amplitude (3-300 pieces) was due toRhipdocotyle illense and minimum parasite number amplitude (1-3 pieces) was due to Argulus foliaceus and Lernaea cyprinicea. Results from this research confirmed the connection between season and age with the Anzali wetland pike parasite infections but did not the connection between genus and their parasite infections.Meanwhile in this research it is for the first time that parasite Corynosoma Strumosum is reported from Anzali wetland pike in Iran.

The intensive culture of common carp (Cyprinus carpio) was surveyed in fiberglass tanks (2×2 m) feeding pellet during 8 weeks.201 fish of common carp were selected from three treatments along with three replicates as the average of fish weight was less than 100 (g) which divided into<50 (g), 50-70 (g) and 70-100 (g). At the first experiment, there was no statistically significant difference between fish weight in relation to replicate treatment. The common pellet food was chosen for feeding from market as fish were fed by the mean of 4% of their body weight a day. The result indicated that the mean of particular growth ratio at first treatment (0.54) was higher than second treatment (0.34) but in comparison with the third treatment (0.46), there was no statistically significant difference (P<0.05). Also, the conversion ratio at the first treatment (5.28) and third treatment (6.09) was lower than the second treatment (35.66) and the third treatment (20.91) was lower than second treatment (24.24). The survey showed the possibility of maintenance of monoculture common carp in small scale by utilizing artificial diet, if the water quality is exposed to change. In this survey, the conversion ratio was relatively high but the growth ratio was low.

Because of being non-degradable in the environment, heavy metals could transfer through food chains. Thus, consumimg the organisms from the high level of these food chains by human could result in metal poisoning. During this study, heavy metal concentration in sediment and Johnius belangerii (mg/g d. w) was measured. The level of metals in sediments and tissues was determined by FAAS. The result showed that the highest concentration of Cd, Co, Cu, Ni and Pb in the sediment was 0.54, 23.18, 17.6, 67.21 and 4.81 respectively. The highest concentration of Cd, Co, Cu, Ni and Pb in muscle was 0.14, 0, 1.68, 2.76 and 4.27 and in liver was 7.02, 1.03, 5.97, 2.26 and 3.58 respectively. The detected metals in edible part of the fish were below the permissible level of FAO, WHO, NHMRC and TEG.