The Chimaeridae, or shortnose chimaeras, are a family of cartilaginous fish.They resemble other chimaeras in general form and habits, but have short, rounded snouts, without the modifications found in related families. Many species have long, tapering tails, giving them an alternative name of ratfish. Shortnose chimaeras have a venomous spine on their backs, which is sufficiently dangerous to injure humans.They are found in temperate and tropical marine waters worldwide.