My engineer brother's silver dollar aquarrium fish is very large, around 1.5 feet long.This fish is a relative of the pacu and the dangerous piranha. The fish has already gobbled two or three hammerhead fishes and even killed a fellow but smaller silverdollar fish just by butting its head on the body of the poor victim. It now shares a large aquarium with an oscar pet fish which suffered lacerations at its mouth perhaps when they were feeding.
