Deep-water fish are some of the most bizarre of all fish, and Sloane’s viperfish is no exception. At one end of its slender body it has a large head with huge, barbed teeth, while at the other it has a tiny forked tail. Rows of photophores run along the sides and belly and light the fish up like a night-flying airplane. During the day, it stays in deep water, but at night it migrates upward to feed where prey is more abundant. The single dorsal fin, just behind the head, has a very long first ray that can be arched over the head and may help entice prey within reach. Sloane’s viperfish spawns throughout the year. It is one of nine species of viperfish, all deep-living.