Also known as the pirarucu, it is the largest freshwater fish in the world reaching the length of 18 ft. It can be found in the Amazon river together with the silver and black arowana. A 4-6 inches juvenile arapaima would cost around PHP 4000-5000 here in the Philippines. Through my friend's experience, it has a big appetite and grows very fast, even a 100 gallon aquarium is not enough for this fish as it often ends up breaking the glass. So quite often you would see arapaima owners building ponds or pools in order to accomodate their pet.
