فصلنامه فیزیولوژی و بیوتکنولوژی آبزیان
سال یازدهم شماره 4 (زمستان 1402)

Ligula intestinalis (Lineaus1758) is one of the most common parasites of freshwater fish. This study was conducted to survey the possibility of infection of freshwater breams (Abramis brama) caught from Siahdarvishan River and their morphological and molecular characteristics were investigated. 75 breams, after dissection, all parts of their abdominal cavity completely were examined for the presence of the L. intestinalis plerocercoids. Then, the morphometric characteristics of parasites were investigated. In the next step, the definitive identification of the genus and species of parasitic samples was confirmed by identification keys. For molecular analysis, the samples were stored at -20°C. Then, molecular studies were done on 10 plerocercoids obtained from 10 separate fish by analysis of ITS2 gene. From 75 A. brama samples, 18 fish (24%) were infected by L. intestinalis. In this study, the minimum, mean and maximum size of the isolated plerocercoids were 8, 26 and 74cm, respectively. Sequencing of the ITS2 gene of L. intestinalis isolates with GenBank samples showed that these isolates had genetic differences in different hosts and based on the comparison of the ITS2 gene locus, and the presence of host-dependent species in the genus Ligula is probable.

One of the most important secondary metabolites of the marine sponges are steroids. The aim of this study is to investigate the antifungal activity of the steroidal fractions derived from the sponge Axinella sinoxea from the waters around Lark Island in the Persian Gulf. Extraction from sponges was done with acetone and separation of fractions was done by column chromatography with silica gel using a range of solvents with different polarity. Identification of steroidal fractions were done by thin layer chromatography and gas chromatography coupled with mass spectrometry. Then, antifungal properties of the steroids were investigated through determining the minimum inhibition concentration and minimum fungicidal concentration by tubular dilution method against Aspergillus fumigatus and Candida albicans. The identified steroids included compounds of Stigmasta, Ergosta, Cholest and Norgorgosta, which showed different results regarding the growth inhibition and killing of fungi and yeast strains at different experimental doses. Stigmasta and Ergosta showed more antifungal effects against A. fumigatus compared with the other steroids and Ergosta caused the best inhibitory and killing effects against C. albicans compared with the other steroids. In conclusion, promising results were found regarding the antifungal effects of the extracted steroids of the marine sponge A. sinoxea, revealing the necessity of more comprehensive investigations for the synthesis of biomedicines from the marine bioactive compounds.

According to high solubility and frequent use of paraquat, large amounts of it can penetrate into surface waters through runoff and have destructive effects on living organisms. Therefore, in the present study, the toxic effects of paraquat on the kidney and the its functional factors, including creatinine, urea, and uric acid, were investigated in benny fish (Barbus sharpeyi). 40 benny fish were divided into 4 treatments including 0% (control, t0), 25% (t1), 50% (t2) and 75% (t3) paraquat lethal concentration (0, 0.38, 0.76, and 1.14mg/L, respectively). After 96 hours of exposure, kidney tissue samples were taken for tissue studies and blood serum sampled to check changes in kidney functional factors. Injuries such as shriveling of glomerulus and renal tubules, hyperemia, destruction of tubule epithelium, dilation of urinary space and decrease in the lumen diameter of urinary tubules were seen in exposure to paraquat. Creatinine in groups t2 and t3 and uric acid in t1 showed significant changes compared to the control group (P<0.05). As the concentration increased, paraquat caused more severe and widespread damage in the kidney. The results showed severe destruction of kidney tissue in the group t3, and as a result, creatinine also increased.

Penaeidae shrimp species are the most important farmed aquatic animals from the crustacean group which have gained an important economic position in the world's aquaculture industry. In this study, complete mitochondrial genome sequences along with nucleotide and amino acid sequences of 13 PCGs per each genome from 10 important Penaeidae shrimp species were obtained from NCBI database and compared. According to the complete mitochondrial genome, the highest (88.5%) and lowest (76.4%) genetic similarity was found between Fenneropenaeus indicus and Fenneropenaeus merguiensis, and Metapenaeus ensis and Penaeus monodon, respectively. In phylogenetic analysis of the complete mitochondrial genome, two main clusters were established at the beginning of the phylogenetic tree. Metapenaeus ensis and Metapenaeus affinis were placed in one main cluster and other species in another main cluster. The results of the phylogenetic analysis of the nucleotide and amino acid sequences of the 13 PCGs showed that M. ensis and M. affinis, Litopenaeus stylirostris and Litopenaeus vannamei, and F. merguiensis and F. indicus species were grouped in different clusters, which confirms the results obtained from the comparison of the complete mitochondrial genome. Based on the results, mitochondrial genome sequences could be used for a wide range of detailed phylogenetic and genetic analyzes of different shrimp species.

In this study, reproduction efficiency and some blood indices and sex hormones of female Cyprinus carpio var. Sazan were studied due to the injection of Ovapas and Ovulin hormones. For this purpose, 24 male and female broodstocks were injected with 0.5 mL/kg of Ovapas and Ovulin hormones during one and two stages. The results of the reproductive efficiency indices showed that the injection of Ovapas and Ovulin hormones had an effect on the number of eggs, fertilization percentage, hatching rate and larval survival percentage (P<0.05), so that the highest fertilization percentage, hatching rate and larval survival percentage were in two-stage injection of Ovapas and the lowest in one-stage injection of Ovapas (P<0.05). The injection of Ovapas and Ovulin hormones had no effect on female broodstocks red and white blood cells, hemoglobin, hematocrit and lymphocytes (P>0.05). However, the number of neutrophils in the two-stage injection of Ovapas increased significantly in the post-injection stage compared to the previous stage (P<0.05). Also, the levels of serum glucose and cortisol increased significantly in the post-injection phase compared to the previous phase in all treatments (P<0.05). Thus, the highest increase in cortisol was in the two-stage injection of Ovulin and the lowest in the two-stage injection of Ovapas. But no effect has seen on calcium, sodium and total protein (P>0.05). In addition, the amount of sex hormones estradiol, progesterone and testosterone increased in all four treatments after the injection of hormones (P<0.05). Thus, the amount of estradiol in one-stage injection of Ovulin and the amount of progesterone and testosterone in two-stage injection of Ovapas were higher than other treatments (P<0.05). The results of this study showed that two-stage injection of Ovapas improves reproductive performance in female broodstocks of Cyprinus carpio var. Sazan.

In this study, the effect of different levels of selenium nanoparticles was investigated on sperm fluid enzymes including aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), superoxide dismutase (SOD), catalase, lysozyme, malondialdehyde (MDA) and albumin in male breeders of rainbow trout. A number of 84 three-year-old male breeding fish were divided into four experimental groups with three replications. Fish were fed with diets containing 0 (control), 0.5, 1 and 2 mg of selenium nanoparticles per kg of diet for 60 days. The results of the analysis of the sperm fluid in different treatments did not show any significant difference in the amount of ALP, ALT and lysozyme in the sperm fluid (P>0.05). The highest amount of ALT enzyme was in the treatment of 2mg of selenium nanoparticles, and the amount of MDA, ALT and ALP of sperm fluid in other treatments was significantly higher than the control treatment (P<0.05). Based on the obtained results, in order to increase the reproductive efficiency of rainbow trout males and improve the antioxidant indices and immunity of sperm fluid, it is recommended to add 2mg of selenium nanoparticles per kg to the diet.