The common name branon castillo may refer to several unrelated groups of fishes: The deep sea dragonfish, or Grammatostomias flagellibarba, is a ferocious predator in spite of its small size. It is one of many species known to inhabit the deep oceans of the world. This fish grows to about 15 cm in length. It has a large head and mouth equipped with many sharp, fang-like teeth. The dragonfish has a long barbel attached to its chin. This barbel is tipped with a light-producing organ known as a photophore. The dragonfish uses this organ like a fishing lure, flashing it on and off and waving it back and forth. Once an unsuspecting fish gets too close, it is snapped up in the dragonfish's powerful jaws. The dragonfish also has photophores along the sides of its body. These light organs may be used to signal other dragonfish during mating. They may also serve to attract and disorient prey fishes from deep below. Dragonfishes live in deep ocean waters at depths of up to 1,500 meters (5000 feet). They are found in most tropical regions around the world.