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This study evaluates the impact of dietary supplementation of the blue-green alga Arthrospira platensis NIOF17/003 nanoparticles (AN) on the growth performance, whole-body biochemical compositions, blood biochemistry, steroid hormonal, and fry production efficiency of Nile tilapia (Oreochromis niloticus) broodstock, during the spawning season. After a 21-day preparation period to equip the females and ensure that their ovaries were filled with eggs, mating between the mature females and males took place in a 3:1 ratio during a 14-day spawning cycle. A total of 384 tilapia broodstock 288 females and 96 males with an initial body weight of 450.53±0.75, were divided into four groups; AN0: a basal diet as a control group with no supplementation of Arthrospira platensis, and the other three groups (AN2, AN4, and AN6) were diets supplemented with nanoparticles of A. platensis at levels of 2, 4, and 6 g kg─1 diet, respectively. The results found that fish-fed group AN6 showed the highest significant differences in weight gain (WG), final weight (FW), feed conversion ratio (FCR), protein efficiency ratio (PER), and feed efficiency ratio (FER). Females fed the AN6 diet showed the highest significant fat content. Compared to the AN0 group, fish fed on the supplemented diets showed significant improvement (p < 0.05) in triglyceride, glucose, and aspartate aminotransferase (AST). A gradual increase in AN inclusion level resulted in a gradual increase in the concentrations of luteinizing hormone (LH), and follicle-stimulating hormone (FSH), testosterone, progesterone, and prolactin. The rates (%) of increase in fry production for females fed supplemented diets were 10.5, 18.6, and 32.2% for AN2, AN4, and AN6, respectively, compared to the control group. This work concluded that the inclusion levels of 6 g kg─1 of A. platensis nanoparticles in the diet of Nile tilapia broodstock significantly improved the growth performances, steroid hormone concentrations, and increased the fry production efficiency by 32.2%, respectively. These findings revealed that A. platensis nanoparticles resulted in a significantly enhanced female' reproductive productivity of Nile tilapia broodstock. [ABSTRACT FROM AUTHOR]

The current study aimed to assess the influence of dietary inclusion of cyanobacterium Arthrospira platensis NIOF17/003 as a dry material and as a free-lipid biomass (FL) on the growth performance, body composition, redox status, immune responses, and gene expression of whiteleg shrimp, Litopenaeus vannamei postlarvae. L. vannamei were fed five different supplemented diets; the first group was fed on an un-supplemented diet as a negative control group (C-N), the second group was fed on a commercial diet supplemented with 2% of A. platensis complete biomass as a positive control group (C-P20), whereas, the three remaining groups were fed on a commercial diet supplemented with graded amounts of FL at 1%, 2%, and 3% (FL10, FL20, and FL30, respectively). The obtained results indicated that the diet containing 1% FL significantly increased the growth performance, efficiency of consumed feed, and survival percentage of L. vannamei compared to both C-N and C-P20 groups. As for the carcass analysis, diets containing A. platensis or its FL at higher levels significantly increased the protein, lipid, and ash content compared to the C-N group. Moreover, the shrimp group fed on C-P20 and FL10 gave significantly stimulated higher digestive enzyme activities compared with C-N. The shrimp fed C-P20 or FL exhibited higher innate immune responses and promoted their redox status profile. Also, the shrimp fed a low FL levels significantly upregulated the expression of both the peroxiredoxin (Prx) and prophenoloxidase (PPO1) genes than those receiving C-N. The current results recommended that dietary supplementation with 1% FL is the most effective treatment in promoting the performance and immunity of whiteleg shrimp. [ABSTRACT FROM AUTHOR]

The current study aimed to evaluate growth performance, digestive enzyme activities, antioxidant status, nonspecific immune response and intestinal histological status of red tilapia fed Daphnia meal (DM) as a substitute for fishmeal (FM). Hybrid red tilapia (Oreochromis mossambicus × Oreochromis aureus) fry (0.54 ± 0.05 g fish−1) was allocated in nylon haba cages (100 fry m−3) for 2 weeks as an acclimation period. The fish were divided into five groups (three replicates each). The experimental diets were prepared by replacing FM with DM at concentrations of 25%, 50%, 75% and 100% respectively. The results indicated that fish fed increasing levels of DM (50%–75%) experienced high growth performance, feed utilisation and protein content. The activities of digestive enzymes were significantly increased in all groups fed DM diets compared to the control. The antioxidant balance was improved by decreasing the level of malondialdehyde and increased the total antioxidant capacity, catalase, superoxide dismutase and glutathione reductase activities in the liver of fish fed DM. The nonspecific immune response, including lysozyme, alkaline phosphatase activities and total protein level improved significantly with increasing FM substitution levels by DM in a dose‐dependent manner. Histometric analysis of the intestinal wall revealed an increase in the villus length, crypts depth and goblet cells number in groups fed DM meal up to 50% substitution level compared to other treatments. It may be concluded from results of this feeding trial that in the aquaculture of hybrid tilapia, FM may be substituted with up to 50% DM without compromising intestinal health, growth performance and immune status of the fish. [ABSTRACT FROM AUTHOR]

Determining appropriate methods to release fish into confined water bodies such as lakes necessitates an awareness of the potential impact on local fish and the ecosystem in general, as well as a cost-benefit analysis. The purpose of this study was to apply various release strategies boosting the survival rate (%) of grey mullet (Mugil cephalus) fingerlings in the lower part of Wadi El-Rayan Lake (WRL) located in Al-Fayoum Governorate, Egypt. This study involved two experiments. The first experiment involved nursing and rearing grey mullet fingerlings in net enclosures (NE-CWT) and an earthen pond for 40 days before releasing them into the WRL. In the second experiment, three groups were studied before being released into the WRL: the first group underwent a nursing experiment (nursing for 40 days for acclimatization), the second group underwent grow out rearing for 334 days, and the third group (control group, continued) was released directly into the WRL, without extended rearing, acclimatization, or CWT recovery. During the first experiment, the growth performance, feed utilization, and survival rates of M. cephalus fingerlings were recorded. Throughout the second experiment, the fishermen collected monthly samples from the WRL to monitor the growth and survival rates of M. cephalus. The data revealed that fish temporarily held in NE-CWT had significantly higher (P< 0.05) final body weight, total weight gain, specific growth rate, and survival rate. Growth trends were similar for the fish temporarily held in EP-CWT. These findings emphasized the significance of short-term rearing and acclimation prior to release for improving the performance parameters of mullet seed compared to direct release into the lake. The study results can be used to increase the effectiveness of future grey mullet (M. cephalus) stockings in the Egyptian lakes. Transferring the results to fishermen's associations in Egypt will provide these groups more time to evaluate and improve the stock enhancement technologies. [ABSTRACT FROM AUTHOR]

Aquacultural scholars and experts should create new plans to sustain aquaculture, with a minimum negative impact on the environment since aquaculture activity affects the environment and is further complicated by the paucity of good-quality water and land. As a result, a symbiotic experiment involving fish and plants was carried out to ascertain how the two organisms affected one another. The deep Flow Technique was created as a hydroponic system in its simplest form. Mentha spicata L. (mint) at 46 cm TL, Ocimum basilicum L. (basil) at 43.5 cm TL, Origanum majorana (marjoram) at 37 cm TL, Salvia Rosmarinus (rosemary) at 33 cm TL, and Origanum syriacum (thyme) at 34.7 cm TL were the plants utilized in this experiment. 400 fish/pond (1.3 g wet weight) of the Oreochromis niloticus L. species of tilapia fingerlings were stocked. A commercial feed for specific species (with a crude protein content of 25 percent) was represented as the diet in this experiment. Four plants and a control treatment comprised the five treatments, each of which had three replicates. The findings showed that using medicinal herbs improved the quality of the water, especially when compared to un-ionized ammonia (NH3) values in both basil and marjoram. Basil and mint ponds had the greatest fish performance results without any discernible variations, while rosemary ponds had the best survival rate at 96.25%. The performance of some medicinal plants as well as the purity of the water is both benefited by symbiotic relationships with both fish and plants. In order to assess the impact of intense culture on the effectiveness of this program, more studies must be conducted. [ABSTRACT FROM AUTHOR]

Aquafeed additive quality and quantity remain pivotal factors that constrain the sustainability and progress of aquaculture feed development. This study investigates the impact of incorporating the benthic diatom Amphora coffeaeformis into the diet of Nile tilapia (Oreochromis niloticus) broodstock, on the blood biochemistry, steroid hormone (SH) levels and seed production efficiency. Broodstock females displaying mature ovary indications were initially combined with males at a ratio of three females to one male. A total of 384 adult Nile tilapia (288 females and 96 males) were used, with 32 fish (24 females and eight males) assigned to each of 12 concrete tanks (8 m³; 2 m × 4 m × 1 m), with three replicate tanks for each dietary treatment, throughout a 14‐day spawning cycle until egg harvest. Fish were fed one of four different dietary treatments: AM0% (control diet), and AM2%, AM4% and AM6% enriched with the diatom A. coffeaeformis at levels of 20, 40 and 60 g/kg of diet respectively. At the trial's conclusion, total protein, albumin, triglyceride and creatinine), SHs (follicle‐stimulating hormone, luteinizing hormone, free testosterone, total testosterone, progesterone and prolactin) and seeds production efficiency of Nile tilapia improved significantly (p < 0.05) in alignment with the increment of A. coffeaeformis supplementation. The findings propose that including A. coffeaeformis at levels ranging from 4% to 6% could be effectively employed as a feed additive during the Nile tilapia broodstock's spawning season. [ABSTRACT FROM AUTHOR]