Obesity is transgenerational epigenetic metabolic disturbance. Although the diet-induced obese (DIO) zebrafish model is well established, reproductive parameters and changes in offspring have not yet been evaluated. Thus, the aim of this study was to evaluate possible changes in reproductive parameters, embryos and offspring (F1) generated by the reproduction of diet-induced obese males and females. The adult zebrafish were divided into two groups receiving a balanced diet (Control group) or overfed (DIO group) were investigated. The dietary protocol was maintained for eight weeks. During this period, males and females in the same group were stimulated through a weekly reproduction protocol. To verify parental obesity, body weight, blood glucose, triglyceride, the hepatosomatic and gonadosomatic index and adipose tissue morphometry evaluations were carried out. Reproductive parameters were evaluated through ovarian and oocyte maturation stage, total spawning, fertility and fertilization index. To verify possible changes caused by parenteral obesity, all offspring were kept in separate groups in correspondence with their parents and were fed a control diet. Plasma glucose, triglycerides, mortality rate, hatching, and deformities were determined. After eight weeks under the diet protocol, the DIO group exhibited characteristic obesity alterations, displaying significant increases in body mass and hepatosomatic and gonadosomatic indices, hyperglycemia and visceral and subcutaneous adipocyte hypertrophy. In addition, high mortality rates, morphologic deformities and high plasmatic glucose and triglyceride levels, with 100% mortality at 60 dpf, were observed for the offspring. Therefore, obesity induction in adults led to negative effects on their offspring, with high occurrence of deformities and mortality.

The objective of this study was to determine the clove oil (CLO) dose as an anesthetic for tambacu juveniles (♂Piaractus mesopotamicus × ♀ Colossoma macropomum) at two temperatures. Sixty-four animals (2.42 ± 0.39 g and 5.19 ± 7.5 cm) were used in a 4x2 factorial design, composed by four concentrations of CLO (25, 50, 75 and 100 mg L -1 ) and two temperatures (25 and 30 °C). Data were submitted to a two-way ANOVA followed by Tukey test. Linear regression analysis was also applied to correlate the induction and recovery times of fish. Deep anesthesia was achieved at all concentrations tested and no mortality was observed during the experimental procedure and after a 24-hour observation period. The shortest time for deep anesthesia (31.75 s) was observed at a concentration of 100 mg L -1 and a temperature of 30 °C, differing significantly from the other treatments. The longest recovery time (> 270 s) was observed at concentrations of 75 and 100 mg L -1 at both temperatures tested. A positive linear relationship between induction time and deep anesthesia (P<0.05) and a negative linear relationship between total recovery time (P<0.05) was observed. The CLO was effective to anesthetize tambacu juveniles in routine management activities. We recommend to use the 50 mg L -1 concentration of CLO and a temperature of 30 °C when considering the induction and recovery times for a deep anesthesia.

This study was carried out to evaluate the effects of feed restriction on the performance and feeding behaviour of Brycon orbignyanus. Ten‐day larvae (72.84 ± 8.61 mg) were distributed in 36 aquariums (density of 15 larvae/L) in a completely randomized design consisting of six treatments and six replicates. The treatments were determined according to the number of feed restriction days: 0, 2, 4, 6, 8 and 10 days (F0, F2, F4, F6, F8 and F10, respectively), totalling 10 days. The results for final weight, weight gain and specific growth rate were significant (p < .05), and F2 and F0 presented the highest values among all experimental groups. The adopted feeding strategies did not influence final survival (p > .05), and no cannibalism behaviour was observed in any of the treatments. F2 and F0 treatments also displayed higher swimming speed (p < .05) among the assessed groups. The time spent searching for and capturing prey was significantly lower in the F0 treatment. Muscular atrophy for the F10 group was observed, and F2 animals presented no significant difference (p > .05) in muscle fibre diameter when compared to F0. Thus, dietary restrictions can be applied as a strategy for B. orbignyanus reared in intensive laboratory systems for 2 days without compromising performance, muscle growth and feeding behaviour.

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