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.

Some hemipteran xylem and phloem-feeding insects have evolved specialized alimentary structures or filter chambers that rapidly transport water for excretion or osmoregulation. In the whitefly, Bemisia tabaci, mass movement of water through opposing alimentary tract tissues within the filter chamber is likely facilitated by an aquaporin protein. B. tabaci aquaporin-1 (BtAQP1) possesses characteristic aquaporin topology and conserved pore-forming residues found in water-specific aquaporins. As predicted for an integral transmembrane protein, recombinant BtAQP1 expressed in cultured insect cells localized within the plasma membrane. BtAQP1 is primarily expressed in early instar nymphs and adults, where in adults it is localized in the filter chamber and hindgut. Xenopus oocytes expressing BtAQP1 were water permeable and mercury-sensitive, both characteristics of classical water-specific aquaporins. These data support the hypothesis that BtAQP1 is a water transport protein within the specialized filter chamber of the alimentary tract and functions to translocate water across tissues for maintenance of osmotic pressure and/or excretion of excess dietary fluid.