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This trial investigated the efficacy of artichoke (Cynara scolymus) extract (AE) on the growth performance, immunity, antioxidant parameters, and resistance against Aeromonas hydrophilaof goldfish (Carassius auratus). For this purpose, a total number of 470 goldfish with initial weight 5.70±0.2 g were fed with four experimental diets including 0 (T0), 100 (T1), 150 (T2), and 200 (T3) mg kg−1diet AE for 8 weeks. At the end of feeding trial, growth performances, serum immune parameters, and mucus antioxidant enzymes were measured. Fish were challenged with A. hydrophila, and the antioxidant and immunity-related gene expression were investigated. Based on the results, the highest final weight (FW) and weight gain (WG) were attained in T2 and T3 (P<0.05). Immune factors including ACH50, lysozyme, and total immunoglobulin in T2 and T3 showed the highest values (P<0.05). The expression of GR, IL1β, TNFα, HSC70, HSP70, and HSP90βgenes in T1, T2, and T3 were higher than the control (P<0.05). The GSTexpression was significantly enhanced in T2 (P<0.05). The present study demonstrated that the administration of AE, especially at doses of 150 mg kg−1, could improve the growth, immunity, and antioxidant parameters, as well as enhance disease resistance against A. hydrophilain goldfish.

This study evaluated the benefits of supplementing Nile tilapia diets with probiotics Saccharomyces boulardii(SB) and Bifidobacterium bifidum(BB) in terms of growth, antioxidant status, immune-related genes, and resistance against heat stress. Fish (with an initial weight of 3.85 ± 0.50 g) organized into four triplicate treatment groups defined as control (T0, no supplementation), Saccharomyces boulardii(T1, 1010CFU/g), Bifidobacterium bifidum(T2, 1.5×10 8 CFU/ mL) and a mixture of both (T3). This trial continued over a 56-day feeding period and fish were sampled for analysis and thereafter, Nile tilapia was exposed to heat shock under a high temperature of 32°C for 48 hours. Results revealed that the highest final weight (FW), weight gain (WG), and specific growth rate (SGR) as well as significantly lower feed conversion ratio (FCR) were observed in the T3 compared to other groups (P < 0.05). Alternative complement activity (ACH50), total Protein (TP), and lysozyme (LZM) improved in fish-fed supplemented diets, and the highest value was observed in T2 and T3 (P < 0.05). Moreover, this combination enhanced antioxidant status, as evidenced by elevated levels of superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT), reflecting improved defense against oxidative stress (P < 0.05). Gene expression analyses revealed increased expression of immune-related genes such as Interleukin 8, Interleukin10, Interleukin1β, tumor necrosis factor, and LYZ as well as antioxidant genes including CAT, Gpx, glutathione-disulfide reductase, SOD, in test groups compared to the control group (P < 0.05). The survival rate in Nile tilapia after heat stress was significantly higher in T3 compared to other groups (P < 0.05). It was concluded from this experiment that dietary inclusion of the probiotics species in combination could be promote growth and immune responses of O. niloticus.

In this study, the effect of different doses of recombinant gonadotropin-releasing hormone (rGnRH) and ovaprim (OVP) was investigated on reproductive function, sex steroid levels, and stress response in female koi carp, Cyprinus carpio, females. For this purpose, female koi carps (980.66 ± 23.46g) were divided into five experimental groups and injected with the following preparation procedure: 0.9% NaCl with 5mg/kg body weight (BW) of domperidone (Dop) (Control, C), 0.5ml/kg BW of ovaprim (OVP); 10μgkg BW-1of rGnRH with 5mg/kg of Dop (rGn10), 25μg/kg BW of rGnRH with 5mg/kg of Dop (rGn25), and 50μg/kg BW of rGnRH 5 with mg/kg of Dop (rGn50). To evaluate sex steroids and stress indicators in the females, blood samples were collected before injection and 6, 12, and 24h post-injection. The results indicated that the females were significantly different in terms of the number of spawned females, with the highest numbers in OVP and rGn25 treatments and the lowest number in the control treatment. Significant differences were observed between hormone-treated fish at the latency period, and the highest latency was obtained in the rGn10 treatment compared to shorter latencies in the other treatments. Sex steroid levels (17β estradiol (E2), testosterone (T), and 17α, 20β-dihydroxy-4-pregnen-3-one (DHP) were affected by the hormonal treatments. Levels of E2 decreased in rGnRH and OVP treatments at 6 and 12h after the injection. T and DHP levels increased in rGnRH and OVP treatments at 6 and 12h after the injection and then decreased at 24h post-injection. Cortisol levels increased at 6 and 12h post-injection and decreased 24h after the injection. No changes were observed in lactate and glucose levels at 6h after the injection, but its levels were significantly higher in hormone-injected treatments than in the control treatment at 12h after the injection. rGnRH could induce spawning, and the highest spawning rate and efficiency were measured in the rGn25 treatment. According to the results, rGnRH may be suggested as an alternative to other hormones used for artificial propagation in koi carp.