The name "viperfish" is also sometimes applied to the lesser weever.A viperfish is any species of marine fish in the genus Chauliodus. Viperfish are characterized by long, needle-like teeth and hinged lower jaws. A typical viperfish grows to lengths of 30 to 60 cm (12 - 24 inches). Viperfish stay near lower depths (250–5,000 feet) in the daytime and shallower depths at night, primarily in tropical and temperate waters.