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Pheromones are molecular signals of hormones or their derivatives that affect the same species in the environment outside the body. The effect of ovary extract of psyllium as a pheromone-containing substance (PGF2α) on pheromone induction and the process of final sexual maturation and changes in male sperm indices of this fish have been investigated and compared in different treatments. Male fish with an average weight of 45 ± 200 g were released in 300 liter fiberglass ponds and after adapting the fish to the environment (for 48 hours), the experiments were performed in 5 experimental groups (one control group, one prostate gland control group and 3 groups Treatment) in which each group consisted of 9 adult male fish. Different concentrations of ovarian extract were added to the water in three treatments of 5, 10 and 15 mg / l as a bath. After 24 hours, the fish were anesthetized and fish biometrics was performed by measuring length and weight. After blood sampling, fish gonads were weighed. The results showed that pheromone induction of ovarian extracts and their positive effect on increasing the rate of sperm counts. Gonadosomatic index as well as testosterone levels at 10 and 15 mg / l treatment and prostaglandin treatment (PGF2α) were significantly increased compared to the control (p <0.001). Sperm density and spermatocrit in the treatment of 15 mg / l (T3) had a significant decrease compared to the control, but the indices of sperm motility rate and sperm motility percentage compared to the control did not show a significant difference. Relative sperm volume in all treatments was affected by pheromone extract and a significant increase was observed compared to the control in T3 treatment (p <0.001). Administration of pheromone extract resulted in control of male reproductive fish reproduction in all experimental groups.

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In the present study, the effects of different probiotics mixtures on growth performance, hematology and antioxidant capacity of Asian seabass (Lates calcarifer) juveniles (30 g). In this study, three bacterial mixtures were used that were isolated from the native aquatic species of Khuzestan and the South of the country, which include: the first group includes different strains of Lactobacillus plantarum, the second group includes L. plantarum with a mixture of L. bulgaricus, L. acidophilus and L. rahamnosus and the third group includes the mixture of bacteria of the first and second groups along with the mixture of Bacillus cereus and B. thuringiensis, which were identified through their quorum quenching features and isolated from Asian sea bass. Four treatments were designed by spraying various bacterial mixture on a basal diet, which included diet (1, control group) on which only sterile physiological serum was sprayed on the diet, diet (2) on which the bacterial mixture of the first group was sprayed on the diet, diet (3) on which the mixture of bacteria of the second group was sprayed and diet (4) which was the mixture of all bacteria was sprayed on it and fed to the fish. The fish was fed with the experimental diets four times a day up to satiation at 30.5 °C for 100 days. In this study, the fish that was fed with 2, 3 and 4 diets had a higher growth performance than the control (p < 0.05), which was associated with an improvement in the food conversion ratio. Blood and antioxidant indices were improved in the fish fed with diets containing probiotics mixture. Treatment 4 had more total plasma protein and albumin than other treatments. In conclusion, the use of a mixture of different probiotics increased growth in Asian seabass that associated with improved health indices in this species.

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The present research was started in 2016 at Bandar Imam Khomeini Marine Fish Research Station. The aim of this project was to produce fertile broodstock and achieve the biotechnique of larval propagation and fry production of the Asian sea bass. In this regard, the Thai fry strain were introduced in the station over three different years and their breeding was done until the pre-breeding stage. After four years, 3- and 4-year-old female pre-brooders and 1.5-year-old male pre-brooders were produced, and in the summer of 2022, these brooders were propagated by artificial reproduction method through injecting. In Khuzestan, the reproduction season begins from June to the end of September at a temperature between 28 and 34 ºC. The fish spawning occurs between 36 and 40 h after injection at midnight. The LHRH-α2 hormone was injected intramuscularly for the artificial reproduction of this species. The percentage of fertilization, hatching, and survival of 3-day-old larvae of Asian sea bass in different months varied between 78-92%, 82-93%, and 75-85%, respectively. From February 2022 to July 2023, 208 brooders were donated to 5 private hatchery sectors in Khuzestan and Hormozgan provinces for the mass seed production of this species. The results of the current project showed that the establishment of biosecurity is the most important principle in the implementation of breeding programs, domestication of new marine fish candidates, and selective breeding programs. Also, Asian sea bass has great potential for reproduction in captivity and mass fry production, and it can help short-term programs for the development of marine cage culture in the southern waters of Iran.

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An eight-week study was conducted to examine the effects of dietary butyric and propionic supplementation levels on growth and gut microflora in juveniles’ sobaity seabream (Sparidentex hasta). In this regard, a basal diet (44% crude protein and 15% lipid) was supplemented with various levels of butyric (BA) and propionic acids (PA) to design seven experimental feeds as follow: 1-control (diet without organic acid supplementation), 2- BA 0.5%, 3- BA 1%, 4- PA 0.5%, 5- PA 1%, 6- BA+PA 0.5% (0.25% BA+0.25% PA supplementation), 7- BA+PA 1% (0.5% BA+0.5% PA supplementation). Three hundred and fifteen fish with initial weight of 28.5±0.5 g were distributed among 21 polyethilene tanks (300 L). The fish were fed with the experimental diets three times a day up to visual satiation making sure that no feed remain at the bottom of the tanks. Water temperature and salinity were 31.3 °C and 46 g/L, respectively. The fish fed with 0.5 and 1% PA or 0.5% blends of BA and PA had higher growth rate than other groups. Also, the improvement of food conversion ratio was observed in the treatment fed with 0.5% PA and 1% BA treatments. Total bacterial count in the gut did not affect by the experimental feeds but lactic acid bacteria count increased with supplementing acidifiers in diet. Based on the findings of this study, 0.5% PA or blends of PA and BA at 0.5% level are recommended for improving growth and gut health condition in juveniles’ sobaity seabream.