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This paper o evaluated different concentrations and exposure times of Mentha × villosa hydrolate for the control of monogeneans in Nile tilapia (Oreochromis niloticus). Mentha × villosa leaves (150 g) were homogenized and the hydrolate was obtained by hydrodistillation for 4 h in a Clevenger apparatus. Fifty tilapia were then divided into ten groups (five fish each) and subjected to therapeutic baths for 15 minutes in five different hydrolate concentrations (0, 10, 20, 40, and 80 ml.L-1;× 2 replicates). After a suitable hydrolate concentration was identified, another 50 tilapia were divided into ten groups (five fish each) and subjected to therapeutic baths at the identified hydrolate concentration for five different durations (0, 15, 30, 45, and 60 minutes;× 2 replicates). In both steps, the mucus and gills were analyzed to determine parasitological indices. The hydrolate concentration of 20 ml.L-1 showed an efficacy of 59.9% and the biggest decrease in pathogen prevalence, average abundance, and average infection compared to the control and the lowest concentration (10 ml.L-1). For duration, the best antiparasitic effects were achieved with the 60-minute therapeutic bath, as it resulted in 89.28% antiparasitic efficacy. Therefore, it was concluded that therapeutic baths of M. × villosa hydrolate at a concentration of 20 ml.L-1 for 60 minutes have satisfactory antiparasitic effects and could be used to control monogenetic infestations in the gills and mucus of Nile tilapia (O. 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.

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.

Este trabalho teve como objetivo avaliar o desempenho zootécnico e o índice de inversão sexual em diferentes frequências alimentares. Foram alojadas 50 larvas em cada uma das 9 caixas de polietileno, de 30 litros úteis, em sistema de recirculação, com filtragem e aquecimento. Foram testadas três frequências alimentares: 2, 4, 8 vezes ao dia, com ração suplementada com o hormônio 17 alfa-metitestosterona (60 mg por quilo de ração), com taxa diária de alimentação de 3 % PV, ajustada semanalmente conforme às biometrias. A taxa de inversão sexual, avaliada através de checagem da eficácia da inversão sexual, não teve diferenças entre os tratamentos, apresentando quantidades semelhante de indivíduos machos, fêmeas e intersexos. A taxa de sobrevivência foi menor no tratamento de 2/dia (69,33%) que nos outros tratamentos (98,67%). No tratamento de 2/dia o peso final foi maior (1,49 g) do que nos tratamentos 4/dia (1,11 g) e 8/dia (1,27 g). A taxa de crescimento específico foi maior no tratamento 4/dia (2,65 %.dia-1­) que no de 8/dia (2,38 %.dia-1) e ambos não diferem do tratamento de 2/dia (2,55 %.dia-1). A uniformidade dos lotes não divergiram entre os tratamentos, variando entre 41,7% a 46,7%.

This work aimed to assess the effect of the probiotic strain, Lactobacillus plantarum, on the levels of leptin, IGF-1 and their receptors on the hepatopancreatic tissues of Nile tilapia (Oreochromis niloticus) and then correlate fish growth performance and gut microbiological parameters. Fish juveniles (±23g) were reared in a recirculation system with constant aeration and temperature (25°C). They were distributed into six polyethylene tanks (45L) and fed twice a day at 5% of the tank biomass with the respective diets: control (commercial diet without probiotic) and supplemented with L. plantarum inoculum (1 x 108 CFU mL-1), both in triplicate. After 30 days of feeding, L. plantarum-fed fishes showed greater weekly growth rate, final weight, and feed conversion rate, in addition to higher count of lactic-acid bacteria and lower count of pathogenic bacteria in the intestinal tract, when compared to the control group. The immunostaining intensity for IGF-1 and leptin hormones was lower after L. plantarum supplementation than in the control group, with no change in the level for receptors. This reduction could implicate important changes in fish metabolism and homeostasis.

The objective of this study was to evaluate the hematological and immunological parameters of yellowtail lambaris (Astyanax bimaculatus), fed with different frequencies of the probiotic (Lactobacillus spp.). Fishes were distributed into 20 experimental units and divided in five treatments: control (0%), 25%, 50%, 75% and 100% of probiotic supply. A higher presence of total leukocytes (47.70 103cell µl-1), lymphocytes (36.11 103cell µl-1) and monocytes (11.58 103cell µl-1) was verified in fish fed 100% of probiotic, showing a directly proportional ratio among the frequencies of the probiotic supply on the availability of circulating cells in the circulatory system (R² 094-0.97). Hematocrit (27.30-34.63%), hemoglobin (7.00-10.90g dl-1), mean corpuscular volume (4.21-5.45 10-5.pg), mean corpuscular hemoglobin (3.45-5.40 10-6.pg), mean corpuscular hemoglobin concentration, (2.99-4.35g dl-1), total protein (44.32-50.26mg ml-1) and total plasma immunoglobulin (27.96-34.08mg ml-1) did not diverge among treatments. The frequency of the probiotic supply interferes with the hematological profile, although lactic acid bacteria were present in the same concentrations in the intestinal tract, regardless of the probiotic supply, there was an increase in circulating leukocytes, especially lymphocytes and monocytes, in lambari fed probiotic with more frequency.

This study aimed to compare the body indexes and hematological characteristics between Astyanax bimaculatus males and females. Four hundred fish were randomly distributed into four polyethylene tanks (100 fish/unit) in a recirculation system and fed four times a day (3% of biomass). After 90 days, ten fish (five ♀ and five ♂) were removed to perform blood tests and to measure weight, height, total length, height/length ratio, condition factor and index determination: vicerosomatic (VSI), hepatosomatic (HSI), and gonadosomatic (GSI). The results showed a higher average weight (g) in females (12.32±0.71) compared to males (6.98±0.75), the same happened to height (cm) = (3.01±0.07) and (2.40±0.05), total length (cm) = (3.01±0.07) and (2.40±0.05), VSI (%) = (11.43±0.81) and (3.55±1.05), HSI (%) = (0.72±0.08) and (0.30±0.04), respectively. Mean corpuscular hemoglobin (pg) was higher in females (3.72±1.20) than in males (2.99±1.51). Regarding the number of thrombocytes (103.µL-1), there was an increase in males (25.71±3.91) compared to females (17.40±6.40).