Iranian Scientific Fisheries Journal
Year:2019 | Volume:28 | Issue:5 |Papers Count:16

In this study reproductive biology of brood stock and larvae rearing technique of Acanthopagrus latus was investigated. Also, different development stages of the egg and larvae in a period of 42 days are described. The diameters of fertilized eggs were 0. 77-0. 85 mm. The eggs hatched in 32 h between 19-21◦ C. The newly hatched out larvae had mean body weight of 84. 6 μ g and total length of 1. 76-1. 87 mm. At the end of this study period, yellowfin seabream larval reached to 5170 μ g mean body weight and standard length of 12. 1-12. 6 mm. Gulping the air and swim bladder inflation occurred during first week of larval life, especially as from the sixth day after hatching. In the current study larvae were able to ingest and digest rotifer, Artemia nauplii and microparticulate diet successfully. High mortality of larvae was observed between days 20 and 30 after hatching. Average survival rate of larvae was around %43, when the study finished at day 42 after hatching. The techniques used in this research to deal with yellowfin seabream brood stock and larvae were found to be suitable and led to successful spawning and larval’ s metamorphosis into fry in captive condition.

In this study, analysis of complete structure of mitochondrial D-loop region with its regulatory motifs was investigated in four species of the Acipenser of Caspian sea (A. gueldenstadtii, A. persicus, A. stellatus, A. nudiventris). DNA extraction was done by acetate Ammonium method and PCR reaction were performed by a pair of specific primers for the complete amplification of D-loop along with sequences associated with tRNA-threonine and proline. Sequencing on amplified fragments were was done on both strands. Repetitive sequence of tandem repeat (mini-satellite) was observed in the upstream site of D-loop region after the sequence of tRNA proline in all species except the Ship. The results showed that the central repetitive units of 83-82 pairs with 3. 2 repetitions in A. persicus and A. gueldenstaedtii and 2. 4 repetitions in A. stellatus were the reason for the length variation in this region. In addition to the central repeat sequences, there were two more repetitive sequences of 39 and 43 bp in this section, which were also present with 3. 2 repetitions. But none of these repetitive sequences was observed in ship. The length of the control region in the A. gueldenstadtii, A. persicus, A. stellatus, A. nudiventris was 921, 870, 826 and 839 bp, respectively. The overall structure of the Dloop region showed that the sturgeon control region is similar to that of other fish, including the homologues of the CSB-conserved blocks, which are located on the upstream of these blocks. According to the presence of tandem repeat (mini-satellite) in control D-loop region and also the importance of these markers in conservation programs for genetic resources it may be possible to use them in screening of sturgeon species.

In order to qualitative evaluation of the sediment samples, the samples were seasonally taken in the Tiab basin for one year from autumn 1994 to summer 1995. Four stations were considered to be sampled that the first was between the south and north Tibet, the second station is located to the south Tiab and the third station located at the subbranch of the canal and the station 4 at the branch of estuary. Two ecological indicators based on macrobenthos community were used to calculate ABC and w-statistic indices. Spatial distribution of macrobenthos density at four stations showed that station 4 with an average of 1467 individual per square meters had the highest density, followed by station 3, 1 and 2, respectively, with 652, 393 and 223 individual per square meters in ranking are next. Amount of weight-based indices showed that the frequency curve in the ABC index is located on the top of the weight curve at all four stations and the w-statistic index with the lowest value is-0. 433 at station 2. The results of this study showed that, although at stations far from shrimp breeding grounds, the diversity is more than those are close to shrimp farms, but biodiversity figures indicate that all areas are affected by effluent from shrimp pools.

Arabian yellowfin sea bream (Acanthopagrus arabicus) is a candidate for cage culture. In this study to improve spawning performance (in quality and quantity) the effects of using human chorionic gonadotropin (HCG), Luteinizing hormone-releasing hormone analogues (LHRHA2), carp pituitary extract (CPE) and a combination of CPE plus LHRH-A2 in females were investigated. The hormone treatments and control were tested in triplicates. Each replicate was stocked with 30 fish with a sex ratio of 1: 1 and the average weights were 675g and 310g for females and males, respectively. In each trial, females were injected twice with the same dose in 24 hours between of either. Spawning occurred in all tanks and the use of all hormones successfully induced spawning in a shorter time. Relative fecundity was found to be significantly elevated in the mix treatment (p<0. 05). Fish in the control group and HCG treatment showed the lowest relative fecundity. Buoyant egg percentage was not significantly affected by different hormones. Results of survival rate percentage in 10 and 35 DPH did not show any significant different between treatments and control group (p>0. 05). Starvation challenge was designed for 3 DPH larvae. Survival rate of larvae in 12, 24, 36, 48, 60, 72 hours after starting challenge did not differ significantly among treatments (p>0. 05). The present study revealed the best spawning performance of A. arabicus was achieved at a combination of CPE plus LHRH-A2, This hormone combination increases the quantity of produced eggs without affecting their quality.

The effects of Conocarpus erectus, Paulownia fortunei extracts and their mixture (50%+50%) on the growth performance, digestive enzymes activity and non-specific immunity of rainbow trout (Oncorhynchus mykiss) were studied. Fish were divided into 4 four experimental groups fed diets with 0% (T1), 1% of conocarpus extract (T2), 1% of paulownia extracts (T3) and their mixture (T4) for 30 days. One-hundred and eighty fish (57. 00± 4. 09 g) were randomly stocked in twelve 70-L Aquarium assigned into three treatments and a control group. The growth performance was significantly increased in all herbal extracts fed fish compared to the control (P < 0. 05); the highest value was obtained by treatment 4. The food conversion ratio (FCR) was improved in all experimental treatments compared to control. The digestive enzymes levels revealed significant increment in fish fed 1% Paulownia extract (T3) in comparison with the other treatments and control. There were no significant difference in protein and albumin levels of fish blood serum in different experimental treatments and control (P > 0. 05). While, glucose and hemoglobin levels were significantly increased in fish fed diets containing plant extract. The results of this experiment showed that the use of conocarpus and paulownia extracts can improve the growth, digestive enzymes and non-specific immunity of the O. mykiss.

Human economic activities have caused many environmental impacts that can be attributed to climate change as the most important side effects. One of the components of climate change is the change in rainfall pattern, time and space distribution of rainfall, and also the reduction of rainfall. Considering the importance of water inputs in economic activities, especially agriculture and fisheries, in the present study, the effect of rainfall change on the value added of the fisheries sector in the short and long term has been studied. For this purpose, the Auto-Regressive Distributed Lag model (ARDL) has been used. The results of this study indicate that rainfall in the short and long run has a positive and significant effect on the added value of the fisheries sector. Rainfall by improving access to surface water and groundwater resources has indirect effects on improving the value added of the fisheries sector. According to the results, it is suggested that fish catch limits be applied in critical areas affected by climate change. Also, in order to adjust and adapt the country's aquaculture sector to shocks caused by rainfall and climate change, the field of technology and production improvement should be provided through providing banking and financing facilities.

This study was carried out to determine the water environmental parameters as risk factors for rainbow trout breeding and rearing farms in the Haraz River. 84 water samples were collected at 6 stations during seven months in 2017-2018. Water samples were analyzed by standard titration and spectrophotometry. Results showed that the range of water temperature (4. 0-17. 0◦ C), weather temperature (5. 0-28. 0◦ C), dissolved oxygen (7. 36-14. 24 mg/l), BOD5 (0. 20-20. 80 mg/l), COD (3. 50-41. 40 mg/l), electro-conductivity (345-650 μ S/cm), turbidity (2-81 NTU), TSS (0. 01-0. 72 g/l), pH (6. 98-8. 15), TP/P (0. 01-0. 15 mg/l), PO4 3-(0. 01-0. 20 mg/l), NH4 + (0. 02-0. 31 mg/l), NH3 (0. 14-4. 36 μ g/l), NO2-(0. 01-0. 21 mg/l), fecal coliform (9-30000 CFU/100ml) and water quality index (48. 5-98. 5) were changed. The results of the stepwise regression analysis indicated that the risk factors of water quality in the Haraz River were fecal coliform, phosphate, turbidity, and BOD5 parameters, and fecal coliform had a higher coefficient factor (beta coefficient) than other parameters (p<0. 05). As a result, according to the average water index of stations (less than 55), water of the Haraz River is contaminated and critical to breeding and rearing trout, but it has acceptable microbial count for fish farming and wildlife. In addition to seasonal conditions such as environmental conditions and rainfall, the way of pound managing has been effective in maintaining water quality.

In the present study, the effect of seven dietary carbohydrate sources on growth performance, feed utilization and amylase activity of Pangasiandon hypopthalmus was evaluated for 12 weeks. Fish subjected to diets containing raw dextrin and potato starch showed a significantly (p< 0. 05) higher growth rate than those fish consuming other experimental diets, except wheat starch diet. Furthermore, fish fed with wheat and corn starch showed significantly higher (p<0. 05) Interaperitoneal fat value than that of fish fed with potato, Alfa and waxy maize starch. Moreover, fish fed with wheat starch had significantly higher (p<0. 05) amylase activity than that of those subjected to other experimental diets, except corn and waxy maize diets. Overall, this study showed that the raw forms of dextrin starch and potato were suitable dietary carbohydrate sources for further scientific studies on the carbohydrate utilisation of P. hypophthalmus.

Development of natural and environmentally friendly antifouling agents is a suitable alternative to solve the global marine fouling problem. In the current study, antibacterial, antimicro algal, anti-barnacle and antifouling activity of non-polar, semi-polar and polar extracts from three parts of the sea cucumber, Stichopus herrmanni, body (i. e. body wall, digestive tract and respiratory tree) were studied. The inhibitory activity assay of n-hexan, ethyl acetate and methanol extracts were evaluated against five bacterial strains, two microalgae species and barnacle larvae. In order to investigate the antifouling performance, the extracts were added to a resin epoxy coats and exposed in the sea water for the duration of three months. Based on Results, the ethyl acetate extract of the body wall with the lowest MIC against S. aureus (0. 500 mg/ml) and I. galbana (0. 125 mg/ml), and the lowest LC50 against barnacle larvae (0. 061 mg/ml), showed the best inhibitory activity. After three months treatment, the coated panels containing 4% extract of ethyl acetate from body wall had the lowest final weight (189. 67 ± 5. 51 g) and lowest fouling cover percentage (74. 76%) among all the panels (P<0. 05). Regarding the high antifouling activity of ethyl acetate extract from the body wall of the sea cucumber S. herrmanni, it is recommended as a potential natural alternative for the antifouling coats.

In recent decades, recovery and identification of digestive enzymes from fish has attracted much attention and new applications for these enzymes have been defined in some industries, such as the food and detergent industries. One of these recovered enzymes is Trypsin, which in this study was extracted and purified from the intestine of Caspian kutum using a three-step extraction method with 50 mM Tris-HCl buffer (containing 10 mM CaCl2 pH 7. 5), 60% ammonium sulfate precipitation and Sephadex G-75 gel chromatography. The Result was an enzyme with 52% yield and a purity of 25. 78-fold. The kinetic parameters of Vmax and Km for BAPNA substrate were calculated using the Michaelis-Menten equation and were 2. 9958 μ mol/mg. min and 0. 5350 mM respectively and Kcat was 6. 2568 S-1. The kutum Trypsin’ s half-life was also calculated as 58. 72 min for BAPNA substrate using the conversion of the enzyme activity graph (in minutes) to natural logarithmic graph and determining its slope. The results showed that it is easy and economical to extract and purify Trypsin from intestine of Caspian kutum and it is kinetically more effective than commercial Trypsin. It is suitable for use in the food industries, fish processing industry, culture media production as well as application in biotechnology research.

The present study aimed to investigate the biodiversity and distribution of fishes in Kohgiluyeh and Boyer-Ahmad Province, and providing an updated checklist of fishes in this province. Samplings were done in the Bashar, Zohreh, Semmeh and Maroun rivers drainages troughout this province during 2017-2018. Overal, 27 specices belonging to 18 genera and 4 families were identified, including ten endemic, fourteen native and three exotic species. From these, 9 more species are listed for the province comparing the previous checklist. Also, ichthyodiversity hotspots in the province were introduced, ichthyodiversity threats were investigated and some protection solutions are suggested.

The use of immune stimulants such as algae has a key role in enhancing of immunity. On the other hand, the presence of nanoparticles affects the physiological status of fish and reduces their immune function. Therefore, the purpose of this study was to investigate the effect of enrichment of diet with algae on carp serum immune parameters in exposure to zinc oxide. 250 common carp were divided in four groups for 42 days, algae-free (treatment 1, control), food containing 0. 5% algae (treatment 2), food containing 1% algae (treatment 3) and food containing 2% algae (treatment 4), then 50% of acute concentration of zinc oxide nanoparticles (1. 5 mg/l) was added to each of the groups over a period of fourteen days. The results of this study showed that in general, experimental treatments had a significant effect on serum protein, immunoglobulin and serum albumin levels (P<0. 05), but there was no significant effect on serum glucose (P>0. 05). Also, experimental treatments had a significant effect on ASA, ALP and ALT levels (P<0. 05). The significantly increased rate of these indices was due to treatments fed with algae. Also, these indices increased significantly in treatment of zinc oxide and also in zinc with algae group. Experimental treatments did not had a significant effect on blood glucose level (P>0. 05). It can be concluded that Padina algae may partially improve the reducing effect of nano-oxide on serum total protein and immunoglobulin levels, which requires further research in this regard.

120 specimens of common carp were treated in salt water with 4ppt, 8ppt, 12ppt treatments and freshwater with three replications for 2 weeks. For histomorphology study in the end of the period thickness of 4μ to 6μ were prepared. Also samples were collected for immunohistochemical and ultrastructural studies. Results showed that at the filament position, the highest and lowest number of chloride cells belonged to 8 ppt salinity and control treatment, respectively. Also at this position, the largest size of the cells belonged to the salinity of 12 ppt and the smallest size belonging to 4 ppt. At the lamellar site, the highest number of chloride cells belonged to 4 ppt salinity and the lowest number belonged to the control treatment without changing in the size. In immunohistochemical studies for Na⁺ /K⁺-ATPase localization, it was found that chloride cells were high in filament epithelium and few in the lamellar epithelium in different salinities. These cells were present with intense immunofluorescence in the apex, base, and between inter lamellar filament. According to the electron microscopy studies, the membrane of the chloride cells of the gill of common carp showed that different apical morphologies as the deep hole, shallow basin and wavy convex. In general, range of tolerance and adaptation of common carp is high to salinity changes due to rapid changes in chloride cells in the direction of entering and leaving water and electrolytes. So that, this species was able to adapt to the changes in environmental different salinity and to survive.

The aim of the current study was to evaluate the effect of dietary Lactococcus lactis subsp. lactis and chitin on blood and serum biochemical parameters and intestine bacteria of common carp. To do the experiment, 360 juvenile carp with mean initial weight of 12± 1. 5 g were randomly distributed in the fiberglass tanks designed based on different levels of chitin 0, 1 and 2% and probiotic 0 and 2% (1 ×107CFU/g) in diet and the experiment lasted for eight weeks. The experimental treatments were including control (treatment 1), probiotic 2% (treatment 2), chitin 1% (treatment 3), chitin 2% (treatment 4), probiotic 2% + chitin 1% (treatment 5) and probiotic 2% + chitin 1% (treatment 6). On the end of the experiment, blood parameters including red blood cell (RBC), Mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), hemoglobin (Hb), hematocrit (HCT), white blood cell (WBC), lymphocyte, eosinophil and monocyte, serum biochemical parameters including total protein, albumin, glucose, cholesterol, triglyceride and intestinal bacterial colony were determined. The results showed that RBC, MCV, MCH, MCHC, Hb, HCT, thrombocyte, monocyte had no significant difference among treatments (p>0. 05), But, maximum level of WBC in treatments 5 and 3 (18. 03± 1. 66, 16. 86± 1. 49 103 mm3, respectively), lymphocyte in treatments 5 and 2 (70. 40± 4. 58, 65. 00± 2. 65, respectively) and eosinophil in treatments 3 and 6 (2. 67± 1. 16, 1. 67± 0. 58, respectively) were observed. Biochemical parameters showed no significant difference among experimental treatments and control, but, there were significant difference among the diets containing probiotic and chitin or/and a mixture of probiotic and chitin (p<0. 05). The intestinal bacterial colony in all treatments except treatment 6 was more than the control (p<0. 05). The maximum bacterial colony count was observed in treatment 4 (653. 33± 25. 17 CFU/g). In conclusion, it seems the addition 2% probiotic, 1% chitin and a mixture of them can improve white blood cells and intestinal bacterial colony in common carp.

This research aims to study is the pattern of metal elements accumulation including copper, zinc, nickel and lead in the muscle, gills, liver and kidney of Schizocypris altidorsalis, in Chahnimeh reservoirs of Sistan. For this purpose, 40 samples were collected randomly from the population in winter and spring (20 samples each season). In the next phase of the research, muscle, gill, liver and kidney tissues of the samples were cut out for further study. Then, the concentrations of heavy metals were measured using atomic absorption. The samples were already prepared and treated by nitric acid of high concentration. The results of the study showed that concentrations of copper, zinc and nickel in muscle tissue in winter season were 43. 01± 1. 39, 143. 08± 0. 63, 8. 01± 0. 53 and 1. 13± 0. 18 μ gr. gr-1 dry weight, respectively. Also these results in spring were 42. 90± 1. 50, 141. 04± 3. 02, 7. 07± 1. 56 and 4. 32± 0. 22 μ gr. gr-1 dry weight respectively. Totally, the highest amount of copper and zinc elements in the liver tissue and lead and nickel elements were measured in gill tissue. Finally, the results of the current research showed that the concentrations of these metals in muscle tissues are higher than limits set by FAO and WHO standards. But, the concentration of nickel was lower than FDA standard.