[Iniaz]

The trick question here is -- 1. live the longest and 2. easy to care. So gold fish and Koi live long but not easy to care - especially Koi. My answer is -- the African Catfish. They grow from one inch to 3 feet long. Maybe more. They eat a lot, crap a lot if there is food. They fast for months if there is no food. They live in water with zero oxygen so you dont have to clean your tank for years. If the water dries up, so long as they are moist, they will still live. They eat vegetation, frogs, lizards, chicken guts, dog food, your fingers, stray cats, your mother-in-law. And like the mother-in-law, they are ugly as sin...