Journal of Aquaculture Development
Year:2014 | Volume:7 | Issue:4|Papers Count:8

The Aflatoxins are a group of structurally related toxic compounds produced by certain strains of the fungi Aspergillus flavus and Aspergillus parasiticus and Aflatoxicosis resulting contaminated foodstuffs are incorporated into the diet. Therefore, it is an important potential toxicant to the most of the popularly cultured fish species. Lack of data regarding the effects of Aflatoxin B1 on Acipenser stellatus requires that applications for complete information on this species are breeding. In the present study toxicity of Aflatoxin B1 (AFB1) was investigated in juvenile sturgeon Acipenser stellatus under controlled conditions were investigated. Seven experimental diets containing different levels of AFB1 (0-, 0+, 1500, 1850, 2300, 2850 and 3500 ppb AFB1/kg) were fed to juvenile sturgeon weighing 7.90±0.12 gr. The experiment lasted for 56 days. External changes and unusual behavior could be observed in any of the fish fed with AFB1 (2850, 3500 ppb) supplemented diets. Mortality was observed in fish fed with highest levels of AFB1 (3500 ppb, 3.5 mg kg-1) from day 6 onwards. After 52 days, fish fed the diet of 3500 ppb AFB1 kg-1 showed significant lower survival (47.50±5.77%) followed by those fed 2850 ppb AFB1 (57.5±2.50%), 2300 ppb AFB1 (65±1.88%), 1850 ppb AFB1 (80±2.67%) and 1500 ppb AFB1 (93.75±1.82%). Significant difference was observed in specific growth rate (SGR), growth rate (GR) and (BW%) and (P<0.05) between groups (P<0.05). Increased all tested blood and some plasma enzymes parameters included ALP, AST and ALT significantly (P<0.05).

Chironomidae larva, also named as bloodworms, have great potential in larval fish nutrition. In this study, indoor production of Chironomids was performed by controlling the physiochemical factors and developing an appropriate condition for these insects to complete their life cycle. Enrichment of lava was conducted by adding 0 (C0), 100 (C100) and 1000 (C1000) milligrams of vitamin C (ascorbic acid) to one kilogram of chicken manure (substrate). Ascorbic acid analysis of Chironomidae larva showed 74.2±15.5 mg/g, 325.0±116.6 mg/g and 779.9±81.3 mg/g in C0, C100 and C1000 respectively, with significant differences among groups (P<0.05). In the second experiment, enriched Chironomids were used for Persian sturgeons larval feeding and were compared with the common live feed (Daphnia) that is regularly used in hatcheries. Length and weight measurements after 14 days of the experimental period showed no significant differences in growth performance (P>0.05). Analysis of ascorbic acid in Persian sturgeon’s viscera showed no significant differences between groups (P>0.05). In conclusion, Chironomids could be cultured in indoor situations and they could be known as an enrichable live food that can meet the nutritional requirements of fish. In this study vitamin C did not have a significant effect on Persian sturgeons larval feeding, but longer feeding periods and implication of unfavorite conditions might demonstrate the beneficial effects of this vitamin.

Following of recent mortality and observation of lethargy, abdominal distention, emaciation and abnormal swimming in (Liza auratus), about 86 fish samples (56 with clinical signs and 30 apparently health) were captured during March 2009 in Mazandaran province. After biometry R.B.C., W.B.C., P.C.V., Hb, M.C.V, M.C.H, M.C.H.C and differential count were evaluated. Also ALT, AST, C3, C4, IgM, Albumin and total protein were measured. Average weight, length and age of samples with clinical signs and apparently health were 193.1±10.2 cm, 30.6±0.4 g, 32.5±0.5 cm, 233±11.3 g, and 3.7±0.1 and 3.9±0.1 years, respectively. Findings revealed significant decrease (p<0.05) in W.B.C, R.B.C, Hb, P.C.V. and (MCHC, g/dl) in affected fishes comparison with apparently health fishes. In opposite, (MCV, fl) were more significant increase in affected fish but (MCH, pg) was no significant difference between two mentioned groups. Also, in W.B.C differential count, significant decrease (p<0.05) was observed in Lymphocyte and Neutrophil cells but Myelocyte cells revealed significant increase in affected fishes (p<0.05). Total IgM, protein and Albumin have significant decrease (p<0.05) in affected fishes comparison with apparently health fishes. Also, C3 and C4 revealed numerical decrement but have no significant difference between two groups. AST and ALT enzymes were more significant increase (p<0.05) in affected fish. Meanwhile, weight of affected fishes have decrease significant difference than apparently health fishes (p>0.05). So, it would be concluded that affected fishes have been revealed macrocytic hypochromic anaemia. Also, findings revealed a kind of prolonged starvation and dystrophy chronic disease in affected Golden grey mullet in Caspian Sea.

Present experiment evaluated effectively of replacement of different levels of silkworm pupae meal as an alternative source instead of fish meal on some blood parameters and biochemical factors for 60 days. 360 juvenile rainbow trout (average weight 55±3.42 gr) in 4 treatments and 3 replications were selected. Treatments were included replacement levels of 0, 5, 10 and 15 percent of silkworm pupae which the first treatment considered as control treatment. At the end of experiment, maximum number of White Blood Cells (WBC) (x104 mm-3) (2.7±0.4) and Red Blood Cells (RBC) (x106 mm-3) (1.25±0.15) (T2), Mean Corpuscular Volume (MCV) (fl) (382.00±33.72) (T4), Mean Corpuscular Hemoglobin (MCH) (pg) (74.33±3.21) & mean Corpuscular Hemoglobin Concentration (MCHC) (%) (20.00±1.00) (T3), Hemoglobin (Hb) (mg/dl) (8.13±0.15) (T3), Hematocrite (Hct%) (41.00±3.61) (T1), Cholesterol (Ch) (mg/dl) (391.33±14.74) & Triglyceride (TG) (mg/dl) (357.33±19.09) (T4) and Glucose (GL) (mg/dl) (79.00±2.65) (control) were measured and recorded. The results show, utilization of silkworm pupae as a replacement for fish meal on diet of rainbow trout does not have inappropriate effects on blood parameters and biochemical factors.

The present study aims to explore the Cheshmekileh River’s water quality using Community of Macrobenthic invertebrates in the year 2010-2011 in four stations and during twelve times of sampling 0.1 m2 surber level. In survey benthic, 47 families belonging to 15 orders and six classes macroinvertebrate in the river was identified. Indicator of biodiversity in the river is among the highest diversity of aquatic insect larvae. Simultaneous sampling benthic some of physical and chemical factors such as water temperature of BOD5, EC and TSS were measured at stations. Result showed the Order Diptera, Ephemeroptera and Trichoptera that at station 1, 2, 3 and Order Diptera, Ephemeroptera and Tubificida were dominant. Also station 1 with the highest rate of 9.07 gm2 benthos biomasses and station 4 with the average weight of 1.11 g.m2 of the lowest levels allocated of total benthos biomass. The survey show that the minimum average an index EPT%, EPT/CH and ASPT was related to the station 4 and highest was related to the station 1. The results show that BMWP and EPT indexes existing a significant difference among the stations in probable level of 5% (P<0.05). According to result specified that changes and stresses existing in the direction of the river, especially residential waste matters has made changes in the composition of Macrobenthic community and the frequency of resistant and filtering groups and the amount of sensitive groups has been relatively reduced.

Present study was carried out on Zayandeh-Rud River, in a 30km distance downstream the Koohrang water supply tunnel to Sudetjan Bridge, all located in Charmahal province during 2008-2009. 6 study stations were determined and river benthic macroinvertebrates were monthly collected using a Surber sampler (1600 cm2, 250mmesh). According to the results, a total of 31 benthic taxa including 22 aquatic insect larvae (11 EPT or sensitive taxa) and 9 other groups such as worms and Gammarids, were identified. Individuals belong to Ephemeroptera and Diptera were dominant in most study sites except for station 2 (Cheshme Dimmeh), which Gammarids had dense population over there. Among sampling sites, station 3 just after a 200 metric tons rainbow trout farm effluent, had the highest taxa richness and the subsequent stations had more EPT richness. Comparing the Hilsenhoff family level biotic index at different stations reveals that a remediation of water quality occurs downstream the effluent receiving point and are classified as "good" water quality (HBI: 4.2-4.8). Organic materials and nutrients coming both from river catchment's area and human activities such as fish farms and adjacent agricultural lands in addition to own life span of macrobenthic animals, seems to be the main determinants of fluctuation in community structure of macroinvertebrates fauna in Zayandeh-Rud River.

The aim of this study was comparison the effect of cow dung as organic fertilizer and chemical fertilizer on microbial flora, fish and human pathogenic bacteria and pysico-chemical parameters of cyprinid fish pond water. The water samples were collected from two ponds, pond 1 was fertilized by cow dung and pond 2 was fertilized by chemical fertilizer, respectively from May to October 2011. For isolating of fish and human pathogenic bacteria, thirty six fish were collected from pond 1 from July to October and then sampled from their liver and kidney. The mean of total count of bacteria and total Coliform in cow dung sample were 4×104±1200 and 470 CFUmL-1 respectively. The mean of water total count bacteria of pond 1 were significantly higher than the water of pond 2. The water total count bacteria of pond 1 were significantly increased in August, but water total count of pond 2 was not shown significant variation from May to October. The results showed that Pesudomonas, Klebsiella, Enterobacter, Yersinia and E. coli were isolated from water of pond 1 but just Pesudomonas and E. coli were isolated from water of pond 2.The bacteria growths were negative in all of the inoculated plate from fish liver and kidney. The total hardness, total phosphorus, total dissolved solid and conductivity of the pond 1 water were significantly higher than the pond 2 water. But the BOD, dissolved oxygen and transparency of the pond 2 were significantly higher than the pond 1 water. There were no significant differences in the total nitrogen, total alkalinity and pH between water of pond 1 and 2.

Probiotics are supplemented bacteria’s which balanced microbial communities of gut. Among them, one is lactic acid bacteria. Due to effect of Pedicoccus lactic acid on growth performance and bacterial flora, was investigated in rainbow trout. For this purpose, 3 treatments (100, 200 and 300 gr pro/feed) and one control treatment were designed. A total of 3600 of rainbow trout with average weight of 4gr was distributed into 12 holding tanks for 60 days. At the end of experiment, there were no significant changes on parameters evaluated. The highest and lowest total length (21.17) and weight (48.9) were observed for treatment contained 300 gr pro/feed and control treatment, respectively. Also, highest total counts of lactic acid (36366 CFU) were recorded for treatment contained 300 gr pro/feed. But lowest values were found for control treatment (g-CFU 6000). Also, values of total counts of lactic acid showed highest and lowest number in treatment contained 300 gr pro/feed and control treatment, respectively. Based results obtained, it can be conclude that bactocell probiotic was effective in weight of fish. In addition, treatment 3 (300300 gr pro/feed) l flora could improve microbial flora in rainbow trout.