Lionfish are a gorgeous but venomous saltwater fish. They have long flashy tentacles and fan like pectoral fins. When they are happy and have their fins spread out they are fascinating to watch. The lionfish is a predator that will consume more than 70 species of fish, great care should be taken when picking tank mates for these beautiful fish. Lionfish can live five to ten years if proper care is conducted in their aquarium. They are not small fish or Invertebrate friendly, they will consume them whole leaving no sign your fish are missing.