JOURNAL OF AQUACULTURE SCIENCES
Year:2020 | Volume:8 | Issue:15|Papers Count:16

Every year, common carp, Cyprinus carpio, fingerlings are released into the northern rivers of Iran to for restocking the Caspian Sea reserves. For artificial reproduction of this fish, hormone injection is inevitable and despite the differences between wild and farmed common carp, the same method is used to induce their sexual maturation in Shahid Rajaei Center in Sari. Therefore, to compare the efficiency of hormone injection in wild and farmed carp, 12 female broodstocks which caught from the Caspian Sea, and 15 farmed broodstocks were injected based on the applied methods of Shahid Rajaei Center in Sari, each in 3 treatments as follows: Twostage injection of common carp pituitary gland extract at the rate of 4. 5 mg per kg of body weight (control), and one-and two-stage injections of sGnRH + domperidone (ovaprim) at a rate of 0. 4 ml per kg of weight as the second and third experimental treatments. All 27 wild and farmed female broodstocks responded to hormone injection. The extracted egg weight and working fecundity were significantly higher in farmed broodstocks and the number of eggs per gram and relative fecundity were significantly higher in wild broodstocks (P<0. 05). Fertilization, eyeing, and hatching percentages were significantly higher in ovaprim treatments than the pituitary treatment in both farmed (93. 20± 1. 12, 94. 36± 0. 46, 91. 87± 1. 93) and wild (95. 51± 1. 42, 94. 90± 0. 01, 92. 43± 0. 15) broodstocks (P<0. 05). A positive correlation was observed between broodstocks weight, extracted egg weight, and working fecundity with each other in both broodstock groups. However, all three parameters were negatively correlated with the number of eggs per gram and the weight of the broodstocks and the weight of the extracted egg were negatively correlated with the relative fecundity. Also, the percentages of fertilization, eyeing, and hatching rates showed a highly significant positive correlation with each other (P<0. 01). In the study of relationships between variables by stepwise regression, no significant relationship was observed between the fertilization, eyeing, and hatching percentages with the weight of broodstocks and the weight of the extracted egg, but in both groups of broodstocks, the quality of eggs had a positive and significant relationship especially with the single-stage injection of ovaprim compared to the pituitary gland. Therefore, the single-stage injection of ovaprim is more suitable for both farmed and wild common carp. Although extracted egg weight and working fecundity were lower in wild than farmed broodstocks due to lower weight of them, hatching percentage in wild broodstocks was higher than farmed broodstocks with a coefficient of 2. 18.

Beluga is one of the most valuable commercial fishery species, and due to water pollution, hydrological changes in rivers, overfishing, and barriers to reach spawning habitats, this species has been categorized as Critically Endangered (CR) by International Union for Conservation of Nature (IUCN). Given that the climate change is occurring, new and intensive challenges for aquatic ecosystems and their habitats will create as a result of this phenomenon. The aim of this study is to investigate the effect of climate change on this species distribution in the future. In this regard, using Species Distribution Modeling (SDM) and MaxEnt, the distribution of Beluga was predicted under optimistic (RCP4. 5) and pessimistic (RCP8. 5) scenarios in two-time scales (2050 and 2080 AD) in the rivers of the southern part of the Caspian Sea basin. In addition, the environmental variables used include maximum river width, elevation, slope, average precipitation, average annual temperature, temperature difference between the coldest and hottest months of the year, and the basins where occupied by species. On the basis of AUC (Area Under the Curve), the model performance in predicting the distribution of the species was assessed high (0. 96). Based on the modeling results, climate change will cause no change in the species' suitable habitats in all scenarios. Therefore, if the current problems do not eliminate this species from its habitats, the probability of its resistance to climate change is high fortunately.

Nowadays, the presence of microplastics in aquatic ecosystems is a serious challenge for aquatic animals. In this study, the accumulation of polystyrene microplastic (PS-MPs) and its toxic effects on histology of liver and intestines of goldfish was investigated. A total of 231 healthy fish with an average weight of 18. 55± 2. 41 g was selected in the spring of 2019. Microplastic were synthesized in two size ranges (0. 25 and 8 μ m) with two different functions (fluorescent and non-fluorescent). The experiments were performed in two stages. Initially, after the adaptation period, 63 fish were exposed to a constant concentration (PS-MPs) of 300 μ g/L of both 0. 25 and 8 μ m PS-MPs. Liver and intestinal tissue were sampled for 7 days and the samples were imaged using a fluorescent microscope. Then, 168 fish were exposed to non-fluorescent microplastics with different concentrations (0, 5, 0. 5, 0. 05 ppm) for 28 days to determine histopathological lesions. The results showed that both sizes can accumulate in liver and intestinal tissues. Examination of liver histopathology showed different complications such as bleeding, necrosis, cell swelling, bile stasis, thinning of the sinusoidal space and accumulation of blood compared to the control group, the severity of lesions increased with increasing concentrations in a group of size. There was no predictable trend, but the intensity of destruction was greater at 0. 25 μ m. Examination of intestinal tissue lesions showed different complications such as necrosis, loss of intestinal villi, vacuolation, villi decay and degeneration of epithelium in both size groups compared to the control group. In general, microplastics have destructive tissue effects on goldfish. Most tissue lesions were observed at the highest concentration (5 mg/l). The severity of particles with a size of 0. 25 μ m was higher than the size of 8 μ m, with destructive effects observed first in the intestine and then in the liver.

In this study, Vanami shrimp were fed Gracilaria corticata alga and Saccharomyces cervesia yeast, then their immunity indicators were studied. A total of 1800 shrimp with 5 gr after adaptation storage were were selected and after adaptation were introduced into nine 10-tons tanks. The first they were tested for disease. Shrimp did not have any bacterial viral diseases. A group was fed Gracelaria corticata as 1500 mg / kg and another tretment with Saccharomyces cerevisiae as 1 g / kg for 25 days. The hemolymph of shrimps was sampled on days 1, 3, 9, 18, and 25. Then, immunity indicators, including THC, TPP, SOD, POD and PO were compared. The results showed that in both treatments, the immunity indicators were significant increased compared to the control group (P<0. 05). In addition, the immunity indicators in the algae treatment showed a higher increase compared to the yeast one (P<0. 05).

The oriental river prawn (Macrobranchium nipponense) is a commercially important farmed species in some countries of Southeast Asia, and an exotic one distributing in lakes, reservoirs and aquaculture ponds in the northern provinces of Iran. This study was conducted to investigate the reproductive characteristics of this species in Alagol, Almagol and Adjigol wetlands. A total of 1284 specimens were collected, and their biometrical data measured. The sex ratio of male to female for the whole region was estimated to be 1: 1. 29. This ratio was different between wetlands. Females were dominated the length groups of 12-20 mm, while males were more frequent in length groups of 24 mm and larger. The spawning season was started in early spring and lasted till mid-summer. The mean condition factor was estimated 1. 038 for males and 0. 64 for females. The mean batch fecundity ranged from 342 in Alagol to 3722 in Adjigol. The relationship of batch fecundity with carapas length and total weight showed an exponential model. The highest volume of the oocytes was observed in Alagol, and the lowest one in Adjigol. The carapas length at first maturity was estimated as 12. 1 and 13. 2 mm for males and females, respectively. Its high fecundity, small first length of maturity, and spawning during warm-water fish farming makes prawn broadly distributed in the area, therefore it is difficult to eliminate it from the inland water ecosystems.

During the early development stages, fish larvae undergo complex changes that result in improved their adaptation to their environment. Shirbot, Arabibarbus grypus, is one of the economical valuable fish in the southwest of Iran due to its high-quality meat and marketing. Hence, the current study was conducted to investigate the morphological changes in its larvae during early development stages up to 50 days post-hatching. The larvae were obtained from the native fish breeding center of Khuzestan Province. Larvae were sampled daily for the first two weeks and then every 5 days until 50 dph. To study the body shape changes of larvae, geometric morphometric technique with the definition of 9 landmark-points was used. Relative warp and regression analysis based on P-value obtained from 1000 replications were used to study the morphological changes during early developmental stages. The changes of morphological stages were visualized based on the deformation grids compared to the consensus one. Based on the results of the geometric morphometric analysis, the larval stages of this species from hatching up to 50 days can be divided into four distinct stages of (1) 1-4, (2) 5-25, (3) 30-35 and (4) 40-50 DPH in terms of morphological changes. The inflexion point of morphological changes was 20 dph. The end of stage 1 coincided with the beginning of exogenous feeding, and stage 2 was more concerned with changes in the body shape, including the increase of the body depth as well as increasing pigment density, especially in the dorsal part of the body, indicating increased fish adaptability for greater maneuverability, camouflage, and increased the ability to prey small organisms. In the third and fourth stages, this species is almost in the form of a miniature form of adult fish, one but with a relatively elongated, fusiform body shape.

This study aimed to investigate the lenght frequency and species composition of fish caught in conical lift-net in May 2018 in two fishing ports of Babolsar and Amirabad by four fishing vessels during 33 torrents at a depth of 50-40 m. After identification, the total length and weight of the specimens were measured. Of the 27967 fish samples examined, the highest relative abundance belonged to Clupeonella caspia (98. 98%) and the lowest one Gasterosteus aculeatu (0. 032%). Number of fish caught in the Babolsar and Amirabad ports were 27610 and 357, respectively. Out of 193 fishes, the highest and lowest percentage of relative frequency fish species were for Alosa caspia (37. 8%) for G. aculeatu (4. 7%). The relative abundance of other species in the ports of Babolsar and Amirabad are Syngnathus caspius was 38. 8 and 28%, G. aculeatu 50 and 0%, Mulets 11. 11 and 18. 2%, A. caspia 0 and 41. 7%, Rutilus kutum 0% and 12%, respectively. The results show that the maximum and minimum frequencies in Babolsar port was 99. 86% for Clupeonella caspia and 0. 03% for C. engrauliformis and in Amirabad were 65. 38% and 6. 04%, respectively, for C. caspia and C. grimmi. Among the Kilka fish caught in the two zones, the abundance of C. caspia and C. engrauliformis were highly dependent on the fishing region (P<0. 01). The results show that maximum lenght abundance of conical lift net in Babolsar and Amirabad fishing ports are 11. 5-12. 5 cm.

Phytoremediation is a sustainable and inexpensive technology and has become popular as an alternative solution to traditional wastewater treatment methods. The aim of this study was to use fish farm effluent as a culture medium for the Azolla and also to improve the effluent. For this purpose, the initial amount of 60 g of Azolla was dvided in two treatments with three replications, including Azolla in the wastewater of Beluga sturgeon farm (SW) and Azolla in the water of Anzali wetland (AL) which were grown in-vitro for 30 days. Sampling of water was performed to evaluate some water quality parameters at 10, 20 and 30 days. At the end of the experiment, the plant growth performance, fatty acid profile, and approximate composition were measured. The results showed that maximum amount of biomass (295. 22 g) and plant width (9. 64 mm) were observed in SW treatment (P<0. 05). Also, the results of fatty acid composition showed that saturated fatty acids in SW treatment had a significant increase compared to AL treatment. However, unsaturated fatty acids in SW treatment showed a significant decrease compared to AL (P<0. 05). In addition, a significant downward trend in the water quality parameters (phosphate, nitrate, and nitrite) was observed in SW treatment on day 30. The highest and lowest contents of fat and moisture were observed in SW treatment (P<0. 05). Therefore, the production of Azolla in Beluga farm effluent can be an effective and cost-effective method due to the rapid growth rate, high ability to absorb the amount of phosphorus and nitrogen in water, as well high nutritional values (protein and lipid contents) and high diversity of fatty acids.

Sodium alginate is a cheap and available biopolymer due to its biodegradability and hydrophilic properties, PH sensitivity and natural nature received more attentions. Therefore, the present study investigates and compares the antioxidant properties of alginate in different concentrations of brown algae of Sargassum vulgare and Padina pavonica. According to the results, both algae had high antioxidant activity and the total amount of phenol antioxidant activity in three concentrations (100, 150 and 200 mg/ml), and chelating ability in three concentrations (0. 1, 0. 5 and 1 mg/ml) in Sargassum alginate were high. Ehereas the Padina alginate had a higher percentage of free radical scavenging DPPH, hydroxyl free radical at concentrations (0. 11 and 1. 83 mg/ml), regenerative power at the concentrations 160 and 320 μ g/ml. There was no significant difference in the inhibition of free superoxide radicals between both algae at any concentration intervals (P>0. 05).

Nowadays, chromosome manipulation of different aquatics is a useful method in improving their genetic characteristics. Tetraploids have four sets of chromosomes in each cell. Tetraploids are one of the most effective methods for producing broodstocks which can be used in androgenesis, gynogenesis as well as is an economical way to produce non-induced triploid populations. Induction of tetraploidy in aquatics are usually done by late physical or chemical shocks, after fertilization and before the first mitotic division of the egg, cleavage. These aquatics are able to produce diploid gametes that can be used to achieve higher levels of ploidy. Survival, growth, and other physiological parameters in tetraploid are different from diploid ones. The percentage of tetraploid induction varies in different individuals and is affected by environmental and shock conditions as well as genetic characteristics. In this article, we will review the mechanism of tetraploid induction, methods of production, application, detection of ploidy levels and performance of tetraploids.

Fungal infections are important in the destruction of freshwater fishes and their eggs in the wild and commercial fish farms. This study aimed to investigate the lethal concentration of HUWA-SAN TR50, which is among the new generation of ecological disinfectant compounds. For thispropouse, atotalof 4000 fertilized eggs of rainbow trout were used in 5 treatments and one control, and each group with 3 repetitions. During the experiment, the water temperature, DO, Ph and hardness were 11± 0. 5° C, 8. 6± 0. 32 mg/L, 7. 7± 0. 41 and 130 mg/l, respectively. During the experiment, the incubators were oxygenated by aeration pumps and mortality was recorded every 24 hours. The results showed that the mortality percentage in treatments was significant different compared to the control one (P<0. 05). Therefore, LC50 of this substance was calculated in 24 hours as 2278. 12, in 48 hours as 1251. 35, in 72 hours as 552. 31 and in 96 hours 312. 40 ppm. Hence the LC50 96 h concentration of HUWA-SAN TR50, is close to therapeutic dosage and it has a relatively more different than its toxic doses. Therefiren, this can be recommended in practical treatment in Rainbow trout hatcheries.

The present study was conducted to evaluate the effects of oral administration of hot-water extract of the brown algae, Sargassum ilicifolium on the growth performance, digestive enzymes, and proximate composition in Penaeus vannamei. In this study, 600 shrimps with an average body weight of 4. 7± 0. 55 g were distributed in 4 treatments with 3 replicates. Shrimps were fed a diet supplemented with 0 (control), 0. 25, 0. 5 and 1% hot-water extract. After a 66-day trial, the results showed a significant increase in the intestine and hepatopancreas amylase and protease activity of the shrimp fed with 0. 25 and 0. 5% hot-water extract. The intestine lipase activity was significantly lower in both treatments fed with 0. 25 and 0. 5% of the hot-water extract, while in the 1% treatment was significantly higher than in the control. The shrimps fed with 0. 25 and 0. 5% hot-water extract showed significantly higher hepatopancreas lipase activity than the control. The proximate composition analysis revealed no differences among the treatments with the control in the amount of fat, ash, protein, and moisture. The growth performance was also not influenced by the different amounts of supplementation. Although the growth parameters were not influenced by the supplemented fed diets, the enhanced enzymatic activity in the intestine and hepatopancreas may result in better efficiency in the prolonged feeding trial. It could be suggested that the use of the hot-water extract of S. ilicifolium as a natural supplementation without any adverse effects on the growth and proximate composition, could be beneficial in shrimp culture.

Approximately 10% of plastic products enter the environment annually in the form of plastic waste. Plastic trash is usually broken down into smaller pieces by physical, chemical, and ultraviolet processes and enters aquatic ecosystems through surface runoff. Therefore, in recent years, the accumulation of plastic waste in aquatic ecosystems has become a global environmental problem. Microplastics and Nano-plastics may enter the aquatic body through feed intake or waterborne pathways. Microplastics (MPs) may enter the body through the gastrointestinal tract or gills and then the circulatory system and be distributed to all parts of the body. Therefore, exposure to MPs may lead to disruption of biochemical homeostasis and bioaccumulation. Since, hematological and biochemical parameters of aquatic animals are a suitable indicator for evaluating aquatic health in environmental toxicology studies. Therefor, this study aimed to review the mechanism of transmission of MPs to aquatic organisms, bioaccumulation potential, and changes in hematological and biochemical parameters.

This study aimed to investigate the effect of different levels of prebiotic Pleurotus ostreatus on hematological indices of Nile tilapia, Oreochromis niloticus exposed to chlorpyrifos toxin. A total of 120 fish were distributed for 42 days in 4 treatments (each with 3 replicates), including control (1), no prebiotic fungi, (2) food containing 0. 05, (3) food containing 0. 1 and (4) food contained 0. 2% prebiotic. Then, 0. 5 ppm of Chlorpyrifos was added to each group for 16 days and their blood parameters were examined. Based on the results, prebiotic alone had no significant effect on erythrocyte count, mean cell volume (MCV), hematocrit, hemoglobin, white blood cell (P<0. 05) but exposure to Chlorpyrifos and prebiotic in combination increased the mentioned factors compared to the control and prebiotic treatments alone. However, the levels of white blood cells and erythrocytes, hemoglobin, hematocrit, and MCHC were higher than the other treatments in the combination of 0. 2 and 0. 1% prebiotic and Chlorpyrifos. It is concluded that the 0. 1 and 0. 2% prebiotic level could have the best effect on the blood indices of Nile tilapia.

This study was conducted to investigate the morphological variations of Sasanidus kermanshahensis, in the Karkheh river drainage. For this purpose, a total of 162 specimens of the Gardekaneh, Bojin, Dinoarab, Doab, Khoramroud, Maran and Sartang rivers were collected. A total of 30 morphometric traits were measured using digital calipers. After standardization, data were analyzed using Kolmogorov-Smirnov analysis, One-way ANOVA and Duncan grouping, Kruskal-Wallis, principal component analysis (PCA), and Multivariate analysis of variance / canonical variate analysis (MANOVA / CVA). The results showed significant differences in 27 morphometric traits out of 30, and the characteristics, including pre anal length, distance between pectoral and anal fins, pre ventral, distance between pectoral and ventral fins, caudal peduncle length and pectoral fin length were effective traits in separating the studied populations. The results revealed high Phenotype plasticity ability of Sasanidus kermanshahensis in different habitats. Also based the results, this species adapts to the environmental conditions of different habitats by shifting the position of its fins throughout the body.

This study was conducted to evaluate the effect of fish meal replacement by Aqupro (processed soybean meal) on growth performance and body composition of juvenile Siberian sturgeon (Acipenser baerii). One hundred and five juveniles Siberian sturgeon (initial body weight 171. 79± 1. 07 g; mean± SE) were distributed in five treatments each with three replictions. The experimintal diets, including different levels of Aqupro (20, 40, 60 and 80 percent) replaced with fish meal. During the 90 days feeding period, the fish were fed with the experimental diets to apparent satiation four times daily (9: 00, 13: 00, 17: 00, 21: 00). At the end of rearing period, growth performance and fish body composition were measured. The results showed there were no significant differencs in growth performance including final weight, weight gain, feed conversion ratio, body weight increase, final length, condition factor, specific growth ratio, protein efficiency ratio, lipid efficiency ratio and survival rate with the control group (P>0. 05). There were no significant differences in crude protein, crude fat, moisture and ash contents of the whole body among the groups (P>0. 05). According to the results, due to the importance of fish meal and its high price, nutritional value of Aqupro and easy accessibility, best growth performance and no negative impact on mentioned parameters in AP60 and AP80 treatments, using of Aqupro up to 60% recommended in the Siberian sturgeon diet.