Considered the largest fish currently living on Earth, the whale shark (Rhincodon typus) appeared 400 million years ago and remains poorly known by scientists. Very mobile, the adult whale shark moves away from coastal areas and lives, almost exclusively, in oceanic habitats located off-shelf. This pelagic species, which mainly evolves in deep waters, commonly sinks to abyssal depths between 1,968 and 2,952 feet (600 and 900 meters) and can even descend to 3,290 – 4,921 feet (1,000 – 1,500 meters), making its observation difficult.