Iranian Journal of Fisheries Sciences
Volume:22 Issue: 4, Jul 2023

Using beetroot, safflower, and scarlet firethorn with ten treatments, three replications, and 600 fish weighing roughly 230±10 gr that were established in a CRD experimental design for 45 days, this study evaluated the pigmentation of the fillet and skin of rainbow trout. Three groups underwent treatments in which dietary sources of plant pigment were given, while a control group did not receive any plant-based pigmentation additive. Five fish from each replication were randomly chosen and euthanized on day 45 of the experiment to evaluate the skin and fillet colors. Three criteria -L* (Brightness), a* (Redness), and b* (Yellowing) were used to evaluate the colorimetric indices after cutting a piece of fillet with skin on the lateral of the body and cooling it for 24 h. According to the findings, there was no significant difference between the experimental beetroot groups and skin color groups for fillets (p>0.05). However, the beetroot group of 10% had the highest percentage of the fillet and skin redness index, while the group without beets had the highest percentage of the yellowing and brightness index. The findings demonstrated that the addition of safflower improved skin discoloration compared to the control group (p<0.05). Scarlet firethorn was not significantly different in the experimental groups from the control (p>0.05). In conclusion, the supplementation of the rainbow trout diet with 10% safflower resulted in better fillet coloration.

The concentration of four major (Na, K, Ca and Mg), seven essential (Cu, Zn, Fe, Mn, Cr, Ni and Co) and three toxic (Cd, Pb and Hg) elements were determined in muscle of nine freshwater fish species (Mesopotamichthys sharpeyi, Luciobarbus xanthopterus, Luciobarbus grypus, Cyprinus carpio, Silurus triostegus, Planiliza abu, Leuciscus vorax, Luciobarbus schejch and Carasobarbus luteus), that were purchased from local fish markets in central Iraqi cities (Baghdad, Hillah and Karbala) during April and May 2017. Atomic spectroscopy and stripping voltammetric technique were used to analyze the samples after microwave digestion. The highest concentration found in mg kg-1dry weight was that of potassium (9014-10879) followed by sodium (999-2039), calcium (797-3081) and magnesium (1206-1819). The essential elements, Cu, Zn, Fe, Mn, Cr, Ni and Co were found at comparatively lower concentrations of less than 60 mg kg-1 d.w., whereas average levels of the toxic elements Cd, Pb and Hg were generally very low ranging between 0.019 and 5.387 mg kg-1 d.w. The average daily contribution of major and essential elements from fish to the Iraqi requirements were found to be 0.7-3.4% and 0.5-12.0% of the internationally recommended standards, respectively. Levels of the toxic elements Cd and Pb stayed behind permissible levels, while the level of mercury was above that level. Controlling agriculture and industrial effluents into the Euphrates–Tigris Basin of Iraq and proper sitting of pond waters to minimize the risk of contamination by heavy metals is highly recommended.

The present investigation was carried out to study the inflammatory response of carp (Cyprinus carpio L.) to the fungus Aphanomyces invadans infection which is known as a causative agent of Epizootic Ulcerative Syndrome (EUS). Thirty two carps with an average length of 13cm (±2cm) were injected intramuscularly with 0.1 ml of the Aphanomyces invadans spore suspension. Two injected fish were sacrificed by an overdose of 10% benzocaine, at 6 hours, 1, 2, 3, 4, 5, 6, 7, 10, 14, 18, 22, 28, 35 and 42 days after inoculation. Blocks of tissue were fixed in 10% buffered formalin then processed and stained with haematoxylin and eosin, Grocott and periodic Acid Schiff (PAS) for histologic examinations. A chronic inflammatory response, consisted of cellular infiltration, vascularization, fibrosis and granulomata formation, occurred after inoculation of spores of Aphanomyces invadans at water temperature of 27°C (± 1.5°C). Macrophages which infiltrated the lesion area in early stages took on an epithelioid configuration at 3 days post injection. In addition to classical Langhans and foreign body type of giant cells which were observed 3 days after infection, also intermediate type was seen in the lesion area. With continuing healing, giant cells reduced in number by 14 days and disappeared at 18 days after injection. Muscle regeneration started at 3 days and the defect area was filled by new muscle bundles by 14 days. Fibroplasia, along with vascularization, started at 3 days and well developed granulomata formed by 10 days and then fully matured granulomata which filled the whole defect area and were surrounded by the normal muscle bundles were observed by 18 days post injection. It is apparent from the results of the present study that healthy carp resist Aphanomyces invadans infection at high temperatures (27°C) by an active defence mechanism and employing a strong inflammatory response.

The study analyzed the effect of Gontscharovia popovii supplement on growth performance, whole body composition, and hematological parameters of Litopenaeus vannamei. The shrimp were fed with 0.5%, 1%, and 2% G. popovii powder for 45 days. The essential oil of G. popovii was analyzed and found to contain a total of 49 compounds. The main compounds identified in the oil were carvacrol, γ-terpinene, and (E)-caryophyllene. The highest activities of phenol oxidase and superoxide dismutase were observed in the control group (5.64±0.14 µg/mL) and 2% concentration (56.24±0.5 µg/mL), respectively. The hematological parameters indicated that the highest values of triglyceride (108±0.88 mg/dl), cholesterol (103.3±2 mg/dl), IgM (268.5±4 mg/dl), and hyaline (5.5±0.22 106 cell/mL) were observed in the 2% concentration. The highest amounts of hemocyte (1.22±0.01 107 cell/mL) and large-granular cells (2.3±0.05 106 cell/mL) were observed in the 1% concentration, while the highest amount of semi-granular cells (4.9±0.15 106 cell/mL) was observed in the 0.5% concentration. The results of digestive enzyme activities showed that the highest activities of amylase (1265.2±22.1 n/kg), lipase (57.1±2.7 n/kg), and protease (245.2±6.12 n/kg) were observed in the 2% concentration, respectively. The results of growth performance indices showed that the highest amounts of weight gain percentage (417.58±3.55 %), weight gain rate (12.5±0.03 g), and specific growth ratio (1.73±0.01 %/days) were observed in the 2% concentration, while the highest amount of food conversion ratio (1.46±0.02) was observed in the control group. Furthermore, the results of whole body composition showed that the highest level of crude protein (18.05±0.1 %), crude lipid (1.08±0.04 %), and moisture (4.7±0.15 %) were observed in the 2% concentration, while the highest level of ash (76.8±0.4 %) was observed in the control group. In general, the findings indicate a beneficial impact of dietary supplementation with G. popovii at 2% to improve blood biochemical and immune indices, digestive enzyme activities, and growth performance in L. vannamei.

Salinity is an environmental factor that affects abalone, H. diversicolor squamata stress and survival in the hatchery and grow-out area. To understand the protective mechanism of HSP70 and HSP90 under salinity stress, a completely randomized design, and one way ANOVA test were carried out with 95% confidence interval. To characterize heat shock protein genes, we used target clones and target plus clones to obtain partial length sequences of two heat stress response-related genes: (1) heat shock protein 70 (HSP70) and (2) heat shock protein 90 (HSP90). The HSP70 and HSP90 genes contain 201 bp and 302 bp which encode 38 and 87 amino acids, respectively. The results of multiple sequence alignment showed that HSP70 and HSP90 sequences were highly conserved compared to other species. Real-time polymerase chain reaction (PCR) results showed that HSP70 and HSP90 were salinity dependent and HSP70 and HSP90 gene expression was quantified by Quantitative Real-Time PCR of hemolymph and leg muscles showing 10ppt salinity shock for 12 h showing higher HSP70 and HSP90 mRNA expression levels higher than the control group at 32 ppt and decreased expression thereafter. Experimental results suggest that these two genes may play an important role in responding to environmental stress caused by decreased salinity. Thus, this study established a theoretical foundation for further in-depth study of mechanisms of protection of abalone molecules against salinity stress.

As the prolongation of shelf life in fish processing is  one of the industrial importance, it seems that food and aquatic scientists have been moving toward a point where more novel and efficient methods for refraining from food wastage like integrative systems using nanotechnology-based approaches. Penaeus semisulcatus(n=24) were covered with saffron nanoemulsionat 0% (control, group 1), 3% (group 1), and 5%(group 2).They were kept at 4 and 8°C until further testing. The samples were assessed for microorganisms, sensory quality, peroxide value (PV), and pH.The lowest total count of bacteria, coliform count, and psychrophilic count  were observed in the shrimp samples covered with 3 and 5% saffron nanoemulsions stored at 4and 8°C, respectively (p<0.05). The lowest PV and pH were seen in the shrimp samples covered with 3-5% saffron nanoemulsions stored at 4°C (p<0.05).It is concluded that nanoemulsions of saffron 3% or 5% can enhance the shelf life of shrimp,P. semisulcatus stored at 4°C and 8°C.

Nowadays, the need to simultaneously achieve the valorization and recovery of fishing waste is critical for addressing environmental challenges and promoting resource sustainability. Fishing waste hosts enzymes that hold the potential for extraction and utilization in various industries. In this sense, the aim of this work was to extract and purify enzymes from the gastrointestinal tract of Myliobatis goodei using low-cost processes. The proteolytic and lipolytic activities of the extracted enzymes were also investigated. In addition, the detergent compatibility of the purified enzyme extract was evaluated to determine its potential application as an additive in laundry soaps. The crude extract was obtained by homogenization of 100g gastrointestinal tract in buffer Tris-HCl (pH=8.0). Then, it was precipitated with ammonium sulfate and purified by filtration. Finally, it was subjected to centrifugation at 10,000 ×g for 30 min at 4°C in an ultrafilters membrane with a 100 kDa cut-off. This purification protocol showed good performance for proteases and lipases as their activity was recovered at each step. The proteolytic activity was assayed using azocasein as substrate at pH 8.0 and 40°C, while trypsin activity was analyzed against the specific substrate benzoyl-arginine-p-nitroanilide. The lipolytic activity was carried out by p-nitrophenol production through the reaction of p-nitrophenylacetate dissolved in 2-propanol at pH 7.0 and 37°C. The compatibility of the enzyme activity with some commercial detergents was evaluated. Additionally, proteolytic and lipolytic activities were tested on spiruline and soybean oil stains and showed a strong ability to remove them from cotton fabrics. Due to its promising properties, the purified enzymes isolated from the gastrointestinal tract of M. goodei may be considered as a potential effective active ingredient for its use in the detergents industry.

The present study examined the effects of dietary dwarf elder (Sambucus ebulus) on hemato- immunological and biochemical parameters and protection against Yersinia ruckeri in rainbow trout. The fish were divided into four groups (in triplicate) and fed diets supplemented with 0, 2.5, 5, and 10% of the powdered leaf of dwarf elder for 8 weeks. The blood samples were taken on weeks 4 and 8 of the trial. The use of dietary dwarf elder did not significantly affect the red bloo cells (RBC), hematocrit, hemoglobin, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC), lymphocytes percentage, glucose, and alanine transaminase (ALT) levels of all the treated groups compared to the control group on weeks 4 and 8. At the same time, the total count of white blood cells (WBC) and the neutrophil percentage in the fish receiving the herb powder were significantly higher than the control group. The highest total protein, albumin, immunoglobulin levels, and respiratory burst activity were observed in 5% group after 4 and 8 weeks. On the 8th week, the lysozyme activity was significantly increased and the triglyceride was significantly decreased in 5 and 10% groups compared to the control group. After 4 and 8 weeks, the treated groups exhibited a significant decrease in the cholesterol and alanine aminotransferase levels compared to the control group. The lowest number of bacterial colonies in the serum antibacterial activity belonged to 5 %, 10 %, 2.5 %, and control groups, respectively. At the end of 8 weeks, the fish were challenged with Yersinia ruckeri and the survival rates of the control, 2.5 %, 5 %, and 10 % groups that were 22.2 %, 60.3 %, 79.5 %, and 68.5 %, respectively. The present findings indicate dwarf elder possesses beneficial dietary effects on immune responses and resistance against Y. ruckeri in rainbow trout.

The fertility indices of the African catfish (Clarias gariepinus) milt diluted in different extenders were investigated using four adult males and two adult females. There were four groups with three replicates each, comprising an undiluted fresh milt group (FM; Control) and three groups of different milt extenders: soya beans milk (SM), citrated egg yolk (CEY), and citrated water (CW). Each extended milt group was diluted at a 1:10 ratio and stored at 4 °C for 48 h prior to spawning. After milt extension, the milt pH, sperm motility and viability, and sperm concentration were determined daily for 7 days. The egg fertilization and hatchability rates, fry survival rate, embryo viability rate (at 8 h and 24 h), and fry gross biometry (13 days post-spawning) were evaluated. The results showed no significant difference (p>0.05) in the diluted milt pH of the different groups. The sperm viability, motility, and concentration significantly decreased (p<0.05) in all groups, although the CEY group had the highest values (p<0.05) compared to SM and CW treatments. No fertilization was observed in SM treatment. It was concluded that as a milt extender for the African catfish, chilled CW was similar to CEY with respect to fertilization, hatchability, and fry survival rates, while a higher fry body weight was obtained in CW compared to CEY. On the other hand, the chilled SM extender stored for 48 h was not suitable for producing fry due to unsuccessful fertilization.

This study aimed to identify the potential fishing zone (PFZ) for shrimp in Bushehr province waters, located in the south of Iran using remote sensing data. The Sea surface temperature (SST) and chlorophyll-a (Chl-a) data were extracted from the +ETM Landsat 7 sensor and MODIS Aqua (EOS PM) satellite images from the summer of 2002 to the summer of 2017. The land-based physicochemical parameters were recorded using a CTD (Conductivity, Temperature, Depth) device in 27 stations in the geographical positions from E 50˚ 44´ and N 28˚ 59´ to E 51˚ 40´ and N 27˚ 33´, in June and July 2017. The shrimp catch per unit effort (CPUE) was calculated from the results of Shrimp stock assessment projects performed in Bushehr province waters by Iran Shrimp Research Center. The highest values of SST-Chl-CPUE fuzzy overlay were obtained at stations 24, 22, 4, 16, 21, 19, 27, 26, 25 and 10. The highest amount of shrimp CPUE was recorded in the areas where the SST was lower and the chlorophyll-a was higher. The results showed a strong and positive relationship between the amounts of long-term shrimp CPUE and fuzzy overlay of SST-Chl-a in the studied area (p<0.05). Based on the results, the potential zones for shrimp capture in Bushehr province waters were Nakhiloo, Mond River, Ra's-e-Khan, Motaf, Heleyleh, and Rostami, which located in the southern and northern parts of the studied area. Results of the validation study showed that 63% of the captured shrimp by commercial vessels were in the introduced PFZ.