Two menacing lizardfish were collected on the trip, from a depth of 2,500m (1.6 miles). “It has just nasty, nasty teeth,” says Bray. Huge eyes help them detect the faint glow of bioluminescence, which is a form of light made by many marine animals. Lizardfish are hermaphrodites, which means they have both female and male sex organs. This is a great reproductive strategy in the vastness of the deep sea, as the fish don’t have to worry about finding a partner of the opposite sex when they want to reproduce – any member of the same species will do.