Temperature and food availability are key drivers of growth and reproductive development in fishes, but information on how they interact is poorly understood. This study investigates the effects of water temperature and food availability on growth, sex ratio and gonadal development of the convict cichlid (Amatitlania nigrofasciata) which is an ornamental fish that may be a useful lab model. For this experiment, 180 juvenile convict cichlid (0.3 ± 0.02 g) were held at three different temperatures (26, 29 and 32 °C as T1, T2 and T3) and fed to satiation (S) or a restricted diet (R: half satiation) during a 56-day experimental period. Specific growth rate was significantly higher in T2S treatment than the other groups. The highest and lowest mean oocyte sizes were recorded in T1S and T3R groups, respectively. The sex ratio of fish held at 29 °C was male biased (female, 21.0%; male, 78.9%), but this was not seen at 26 °C (female, 47.6%; male, 52.4%) or 32 °C (female, 57.1%; male, 42.9%). In T1S and T1R treatments, oocytes developed more than the other treatments and in T2S group testicular development was more advanced than other groups. These results demonstrate the complex interplay of temperature and food availability on growth and reproductive development in the convict cichlid. Appropriate food availability significantly improves growth and reproductive processes, while restricted feeding decreases growth, survival rate and reproductive performance.

To understand whether soluble fiber (SF) with high water-binding capacity (WBC), swelling capacity (SC) and fermentability reduces food intake and whether it does so by promoting satiety or satiation or both, we investigated the effects of different SFs with these properties on the food intake in rats. Thirty-two male Sprague-Dawley rats were randomized to four equal groups and fed the control diet or diet containing 2% konjac flour (KF), pregelatinized waxy maize starch (PWMS) plus guar gum (PG), and PWMS starch plus xanthan gum (PX) for three weeks, with the measured values of SF, WBC, and SC in the four diets following the order of PG > KF > PX > control. Food intake, body weight, meal pattern, behavioral satiety sequence, and short-chain fatty acids (SCFAs) in cecal content were evaluated. KF and PG groups reduced the food intake, mainly due to the decreased feeding behavior and increased satiety, as indicated by decreased meal numbers and increased inter-meal intervals. Additionally, KF and PG groups increased concentrations of acetate acid, propionate acid, and SCFAs in the cecal contents. Our results indicate that SF with high WBC, SC, and fermentability reduces food intake—probably by promoting a feeling of satiety in rats to decrease their feeding behavior.

Food reformulation, either to reduce nutrient content or to enhance satiety, can negatively impact upon sensory characteristics and hedonic appeal, whilst altering satiety expectations. Within numerous food systems, perception of certain sensory attributes, known as satiety-relevant sensory cues, have been shown to play a role in food intake behaviour. Emulsions are a common food structure; their very nature encourages reformulation through structural design approaches. Manipulation of emulsion design has been shown to change perceptions of certain sensory attributes and hedonic appeal, but the role of emulsions in food intake behaviour is less clear. With previous research yet to identify emulsion designs which promote attributes that act as satiety-relevant sensory cues within emulsion based foods, this paper investigates the effect of oil droplet size (d4,3: 0.2–50μm) and flavour type (Vanilla, Cream and No flavour) on sensory perception, hedonics and expected food intake behaviour. By identifying these attributes, this approach will allow the use of emulsion design approaches to promote the sensory characteristics that act as satiety-relevant sensory cues and/or are related to hedonic appeal. Male participants (n=24) assessed the emulsions. Oil droplet size resulted in significant differences (P<0.05) in ratings of Vanilla and Cream flavour intensity, Thickness, Smoothness, Creamy Mouthfeel, Creaminess, Liking, Expected Filling and Expected Hunger in 1h’s time. Flavour type resulted in significant differences (P<0.05) in ratings of Vanilla and Cream flavour intensity, Sweetness and Liking. The most substantial finding was that by decreasing oil droplet size, Creaminess perception significantly increased. This significantly increases hedonic appeal, in addition to increasing ratings of Expected Filling and decreased Expected Hunger in 1h’s time, independently of energy content. If this finding is related to actual eating behaviour, a key target attribute will have been identified which can be manipulated through an emulsions droplet size, allowing the design of hedonically appropriate satiating foods.