The trout, when first upgraded, is perhaps the smallest animal in the game. It is also the first animal with a tail, which unlike most animals'tails, cannot be bitten by its prey. Its body colored a rosy brown, with two pectoral fins, two adipose fins and one caudal fin.
It is recommended that if you want the oceananimal upgrade chain, to upgrade to rabbit first because they can eat plankton while trouts can not. Plankton can help you level up quicker than being a trout and eating berries.