However, relatively few data exist concerning this shark, probably due to its deep water habitat. Sixgills are distributed worldwide in temperate and tropical seas and are typically found below depths of 100 meters. Several reports have identified sixgills at depths greater than 2500m. Adults reach a total length of at least 4m.
Color ranges from dark brown to dark silvery gray, and they posess large, opalescent eyes.
Such a characteristic would be advantageous to these slow swimming and wide ranging predators in order to camouflage themselves in different habitats and approach fast swimming fish undetected. Sixgills feed on a wide variety of prey.