Production systems that use lower volumes of water than conventional systems such as Recirculating Aquaculture Systems (RAS) and Bio-floc Technology (BFT) are available, but they are not widely used in farms yet. The BFT, especially, can expand the aquaculture production without increasing the use of the basic natural resources (water and land). This technology has become a promising alternative to promote the sustainability and biosecurity of aquatic animals by the utilization of smaller volumes of water, causing less damage to the environment (^{Avnimelech, 1999}; ^{Naylor et al., 2000}).

The objective of this study was to evaluate the effects of dietary supplementation with different doses of Curcuma longa hydrolate on the hematological, immunological and zootechnical parameters of Nile tilapia cultivated in a recirculation system (RAS). Nile tilapia (Oreochromis niloticus) were used, distributed in 16 polyethylene boxes, divided into four treatments: 0.0%; 2.5%; 7.5% and 10.0% of Curcuma longa hydrolate, in quadruplicate. After 45 days of treatment, four fish per experimental unit were anesthetized to remove blood aliquot for hematological and immunological analyzes and dissect the liver to evaluate the hepatosomatic index and final biometry. In the haematological analysis, the fish fed with 2.5% had a higher number of leukocytes, monocytes and lymphocytes than control, while the doses of 7.5% and 10.0% did not differ. Antimicrobial activity showed a significant decrease as the dose of C. longa hydrolate increased. The other hematological, immunological, hepatosomatic index and zootechnical data did not differ between treatments. Thus, supplementation of the hydrolate of Curcuma longa at a dosage of 2.5%, improved and maintained blood-immune homeostasis parameters in these animals, being suggested for further studies.

This study aimed to assess the final body weight, weekly weight gain, yield, apparent feed efficiency, protein efficiency ratio, and feed intake of the Pacific white shrimp (Litopenaeus vannamei) fed four diets containing different levels of soy protein concentrate (SPC) as a replacement for fishmeal, reared in a super-intensive biofloc system. Diets consisted of replacing 209 g kg^-1 fishmeal at 0, 33, 66, and 100% SPC. Shrimp were raised in a biofloc system using twelve experimental units stocked with 250 shrimp m^-3 under constant aeration (O2>5mg L^-1) and temperature (29±0.5 °C). No significant differences among treatments were observed based on water quality parameters. Shrimp fed diets with 0 and 33% substitution exhibited the highest weekly growth (1.88 and 1.79 g per week) and final weights (15.2 and 14.7 g) compared with shrimp fed the 66 and 100% replacement. A lower feed intake was observed for shrimp fed the 33% SPC diet (3.18 kg per experimental unit) compared with 0% replacement (3.62 kg). Shrimp fed the 33% replacement achieved a similar performance and lower feed intake than animals fed diet without replacement.

The LAB has shown beneficial effects in main aquatic organisms reared in Brazil, such as Nile tilapia juveniles (^{Jatobá et al., 2008}, 2011; Van Hai, 2015) and fingerlings (Jatobá e Mourinõ, 2015) and white Pacific shrimp (^{Vieira et al., 2008}; Jatobá et al., 2011). In all of these researches, probiotics have been constantly offered for fish and/or shrimp, and they have reported positive changes in host microbiota and immune system, although there are few studies that aim to optimize the probiotic use. Thus, the aim of this research was to evaluate the action time of LAB (Lactobacillus plantarum) in the intestinal tract, as well as, in what frequency the LAB should be offered, for Nile tilapia (Oreochomis niloticus).

The aim of this research was to evaluate the changes in intestinal tract microbiota, hematological parameters and zootechnical indexes of yellowtail lambaris (Astyanax bimaculatus) fed with different probiotic supply frequencies (Lactobacillus spp.). Lambaris (1,200) were distributed in twelve boxes, divided in three treatments, 100% supply; 25% and 0% (control) of feeds supplemented with probiotic. After 87 days, fish fed with supplemented diet, regardless of frequency (100% and 25%), showed an increase in the total lactic acid bacteria count of 7.99±0.15 log CFU mL^-1 and 7.04±1, 29 log UFC mL-¹ respectively, in the intestinal tract and decrease of Pseudomonas spp. in both 100% and 25% (4.09±0.84log UFC mL^-1 and 4.00±1.12log UFC mL^-1, respectively) in relation to the control treatment (6.74±1.04log UFC mL^-1). Fish fed with 100% of diets supplemented with probiotics had a higher leukocyte count (47.7±6.7x103μL^-1), lymphocytes (36.0±2.6x103μL¹), monocytes (12.0±4.2x103μl^-1), as well as higher mean final weight (10.60±0.89g) and weekly growth rate (0.80±0.08g.week^-1) than the other treatments (25% of probiotic offered and control). Probiotic (Lactobacillus spp.) offered in 25% of feeds (or more) alters the yellowtail lambari microbiota (A. bimaculatus); however, must be offer in 100% of feeds to improve the hematology profile and productive performance.