نشریه علوم و فنون شیلات
سال دهم شماره 4 (پیاپی 36، پاییز 1400)

The present study was conducted to evaluate the effect of fish meal replacement with yellow meal worm (Tenebrio molitor) (TM) on growth performance and proteolytic enzymes activity of trypsin and alkaline protease in koi (Cyprinus rubrofuscus) juvenile (weight: 0.95 ± 0.15 g) for 8 weeks. Five experimental diets were prepared with replacement levels of 0 (control), with 25% (D1), 50% (D2), 75% (D3) and 100% (D4) of fish meal with TM as isonitrogenous and isoenergetic in triplicate. Parameters of body weight gain, specific growth rate and condition factor in control, D1 and D2 diets were not shown a significant difference, while these indices had a decreased amount in D3 and D4 diets significantly (p < 0.05). The highest amount of feed conversion ratio was indicated in control and D1 diets with a significant difference than those from other treatments (p < 0.05). The survival rate was 100 % in the diets. The lipid efficiency ratio and the protein efficiency ratio in diets control, D1 and D2 were significantly the higher than other treatments (p < 0.05). The highest activity of trypsin and alkaline protease enzymes from intestine was observed in control, D1 and D2 groups which showed a significant difference compared to D3 and D4 groups (p < 0.05). The findings of growth performance and protease enzymes activity were revealed that the diets containing up to 50% TM could be appropriate for koi growth.

The aim of the present study was to investigate the possibility of replacing phosphorus chemical fertilizer (triple superphosphate) with biofertilizers as an environmentally friendly approach.  In this study, Possibility of replacing Triple superphosphate fertilizer with phosphate solubilizing bacteria "Pseudomonas deceptionensis Persian10 strain" in 10 treatments with two bacterial factors (in two levels of inoculation and non-inoculation) and chemical fertilizer (in five levels 0, 25, 50, 75 and 100% of the recommended amount of fertilizer in the pond) was examined in aquarium conditions. Treatments included: 1: 100% fertilizer + bacteria, 2: bacteria, 3: 25% fertilizer + bacteria, 4: 50% fertilizer + bacteria, 5: 75% fertilizer + bacteria, 6: 100% fertilizer, 7: 75% fertilizer, 8: 50% fertilizer, 9: 25% fertilizer, 10: control (without fertilizer and bacteria). Bacterial densities, soluble phosphorus, phosphatase and pH were measured on days 0, 2, 7, 12 and 17. The results showed that the phosphorus of all treatments had an increasing trend on different days and at the same time, an increase in the pH value and a decreasing trend was observed in the bacterial population and the amount of phosphatase enzyme. The highest amount of soluble phosphorus was observed in treatments 4 and 5. According to the obtained results, the application of 50% phosphate fertilizer + phosphate solubilizing bacteria can be recommended as a suitable ratio for the fertility of fish ponds and reducing the use of chemical fertilizers.

In this study, the effect of different amounts of rainbow trout bone micropowder (concentrations of 0.5, 1 and 2%) on the shelf life (the rate of formation of secondary fat oxidation compounds, total volatile nitrogen compounds, water holding capacity, color parameters) and the gel quality (hardness, chewing, cohesiveness and folding characteristics) of the largehead hairtail (Trichiurus lepturus) were examined during 15 days of refrigeration. Addition of bone micropowder to the gels prepared from hairtail fish, affected some of the gels properties. The results showed that with increasing the amount of bone micropowder in surimi gels, the amount of thiobarbituric acid (as the most important indicator of advanced degradation due to fat oxidation) was lower than to control group, which indicates the inhibitory effect of micropowder on lipid oxidation in the prepared surimi. In terms of color parameters, the results showed that horsetail fish gels containing bone micropowder had a darker color than the control. In the Folding Test, the horsetail gel containing bone micropowder with a concentration of 2% received the highest score. In the characteristics of texture profile (hardness, chewiness and cohesion indices), it was found that with increasing the amount of bone micropowder, the texture properties in the prepared surimi were significantly improved (p <0.05). Findings from the present study showed that bone micropowder due to its positive effect on the main indicators can be used to improve the texture properties of horsetail fish surimi gel.

The aim of this study was to investigate the antioxidant and antibacterial effect of green bell pepper essential oil for qualitative comparison of silver carp sausage with meat sausage during refrigeration and also to replace some of the nitrite sodium (NaNO2) used in meat products. The essential oil was extracted from green bell pepper by the Clevenger method and ascorbic acid, phenolic compounds, free radical scavenging (DPPH) tests were performed to determine the antioxidant and antibacterial power. The essential oil extracted in three concentrations of 0, 2, and 4% was added to sausage samples prepared from silver carp and meat. Samples were stored at 4 ° C for 30 days. Chemical tests (pH, TBA, and TVN) and microbial evaluation (TMC, PTC, coliform, and mold and yeast) were performed at intervals of 5 days for 30 days in 3 replications. Results of pH, TBA (mg MDA / Kg fat), TVN (mg N / 100g Flesh), TMC, Pseudomonas, coliform and mold and yeast (CFU/g) on ​​day 30 for control treatment of fish sausage (minimum shelf-life) were 7.63, 3.4, 45.3, 11.6, 11, 2.5, and 1.5, respectively, and meat sausage treatment containing 4% of green bell pepper essential oil (maximum shelf -life) were 7.35, 1.86, 34.5, 5.3, 4.9, 0.62, 0, respectively. The results showed that 4% green bell pepper essential oil can be used as a suitable natural preservative in meat and fish sausages.

In the present study, the effect of phytohormone gibberellin on some physiological parameters of Tetraselmis suecica microalgae was investigated. Algae culture was performed under standard conditions with Gillard culture medium, temperature 25 ± 2 C°, light intensity 16: 8 (light/dark), salinity 25 ± 2 mg / l, and 24-hour aeration for ten days. Concentrations of 10, 20, 40, and 60 mg / l were added to the algae culture medium. Growth factors, pigments, photosynthetic factors, and biochemical composition were measured in the log phase. Based on results,  the highest rate of cell growth was observed in the treatment of 60 mg / l, although in other treatments there was a significant difference with the control (P <0.05). The highest amount of protein and carbohydrates was observed in the treatment of 60 mg / l (P <0.05). ). Total lipid content increased from 15.23 in control to 18.53 in 60 mg / l (P <0.05). Antioxidant potential, pigments, photosynthetic factors, and dry weight also showed a significant difference in the concentration of 60 mg / l compared to the control (P <0.05). The highest amount of chlorophyll a and chlorophyll b was observed at concentrations of 60 mg / l (P <0.05). Based on the results, gibberellin has a high potential for cell division, final density, antioxidant potential, cell size, and biochemical composition of Tetraselmis suecica. Also, Tetraselmis suecica can be a good candidate for marine aquatic larvae, drugs, antioxidants, and a rich source of compounds in biofuels.

To aim health risk assessment and determination of consumption rate limit of King soldier bream (Argyrops spinifer), Pickhandle Barracuda (Sphyraena jello), and Japanese threadfin bream (Nemipteru japonicus), 33 fish specimen was harvest from Jofre fishing area. After transport fish to the laboratory, was prepared and concentration of heavy metal iron, manganese, and cobalt was measured by Inductively coupled plasma - optical emission spectrometry, (ICP-OES). The Concentration of heavy metal in the muscle of fish compared with international standards.  For health risk assessment Target Hazard Quotients (THQ) and Total Target Hazard Quotients (TTHQ), for determination of consumption rate limit estimated daily intake (EDI) and estimated weekly intake (EWI), Consumption Rate Limit (CRlim) and Consumption Rate Limit meal month (CRmm) in two groups include adults and children were calculated.  The Results showed that manganese content in all three fish species (36.59 to 55.48 µgr/gr) more than the world health organization (WHO) and the United States Environmental Protection Agency (USEPA). Also Cobalt content in Argyrops spinifer and Sphyraena jello (66.62 and 0.38 µgr/gr) more than WHO. According to THQ, TTHQ, EDI, and EWI, the Consumption of none of the three fish species had not health risk for the consumer. Additional to the highest CRlim in adults and children determinate as in Argyrops spinifer and Sphyraena jello was manganese, respectively (10.12 and 2.17 µgr/gr), (29.36 and 6.29 µgr/gr) and in Nemipteru japonicus (184.25 and 39.48 µgr/gr) Cobalt determinate.

Fish consumption is increasing due to the global population growth. Therefore, taking advantage of new methods such as marine aquaculture can be a reliable source for the production of fish in the world. The purpose of this study is the spatial analysis of marine aquaculture farms in the coasts of Mazandaran province.

In this study, three categories of criteria (water quality, economic-social and physical-environmental) were considered for spatial analysis of aquaculture farms in the coasts of Mazandaran, which are based on the Geographic Information System (GIS) and hierarchical analysis process (AHP), is used according to the definition of the decision law, and at the end, the existing aquaculture farms (9 farms) are analyzed using the Extract function.

The results show that the location of the present farms can be transferred to more favorable areas with less risk. Among the existing farms, farms 1 and 2, located on the coasts of Joibar and Babolsar, have the most suitable condition and the highest amount of desirability. Also, the results of weighting between the three groups of water quality parameters show physical and socio-economic; Due to the importance of temperature, turbidity and chlorophyll criteria in marine aquaculture, water quality group has more weight than other groups (0.4034) and then the group of physical factors (0.3808) than social factors. (0.2168) more weight is given.

The findings of this study show the ability of GIS as well as satellite imagery to locate and evaluate marine aquaculture.

Government support for attracting investment in Persian Gulf marine fish farming has provided the grounds for Iran's fisheries development. Sea bass is a valuable species in the global market that, while helping food security and exports, also brings offshore security to the country by farming in marine cages. Production of more than 26,000 tons in the five years leading up to 2019 and its 45% growth in southern Iran promises more success for it. The study reviews Iran's position in the production of Sea bass fish in the southern waters of the country and identifies its strengths, weaknesses, and opportunities and threats. Therefore, with self-sufficiency in the supply of fry and inputs, strengthening training and research in the field of marine fish, organizing the internal market and continuous monitoring of the international market, monitoring pollution and its environmental impact assessment and developing the support chain of related industries before and after Will be able to provide sustainable development.

This study was conducted to investigate the possible effects of cages culture Asian sea bass fish (Lates calcarifer) on the population structure of macrobenthos in the Rigo area of Qeshm Island in Hormozgan province during a breeding period in 1397 were investigated. The average abundance of macrobenthos at the location of the cages culture and the refrences site in this study was equal to (52765 ± 19154 in m2) and (50642 ± 21002 in m2), respectively.The results showed that at the time of the study among the identified the genus of Ammonia sp. With a relative abundance of 73.41 percent at the location of the cages compared to the control station and Archasterope sp., Spirolochulina sp. and Nephtys sp. with a relative abundance of 63.9%, 49.1% and 12.6%, respectively, were more dominant in the control station compared to the location of the cages.The loading rate of organic matter in the bed of the cages was significantly affected by fish farming activities and in some times showed a significant difference with the control station (P<0.05). In general, at the time of the study, activities related to fish farming in cages had no effect on the population structure of macrobenthos in the study area.

The objective of this study was to control the reproductive cycle and increasing the efficiency of the production of pikeperch (Sander lucioperca) through determining the effects of different photoperiods on reproductive performance and egg and larval quality.

Pikeperch broodstock with mean weights 1367 ± 55.3 g were exposed to three different photoperiods with light intensity 630 lux including constant light (24L), constant darkness (24D), and 12 h of light, 12 h of darkness (12L:12D) with three replicates for 40 days.

The results showed that the pikeperch reproductive performance was affected by photoperiod. Broodstock under 24L spawned earlier than those of the other photoperiods. The highest spawning were observed in the morning in 24L (66.7 ± 3.5%) and the lowest spawning belonged to the 24D and 12L:12D that never spawned at night. Although fertilization rate and number of eggs per gram  did not show any significant difference in various photoperiods, the timing of spawning and the egg quality exhibited remarkable difference.

The results of this study pointed out to effective application of photoperiod on changing the spawning time, reproductive and induction of out-of-season spawning of pikeperch broodstock. Additionally, these results unequivocally prove that the reproductive performance of pikeperch can be considerably improved and stimulated by an effective photoperiod.