Needlefish (sometimes called long toms) are long, slender fish, up to 1.5m in length and comprise up to 34 individual species. Their most distinctive feature is their long, narrow beak, which houses multiple sharp teeth. They have a single dorsal fin, located to the rear of the bosy, close to the anal fin.
These fishes live at the surface and are protectively colored for this mode of life by being green or blue on the back and silvery white on the lower sides and belly. They often have a dusky or dark blue stripe along their side
In most species, the upper jaw only reaches its full length in adults, so the juveniles have a half-beak appearance, with an elongated lower jaw, but a much smaller upper one. During this stage of their lifecycle, they eat plankton, switching to fish once the beak fully develops.
All needlefish feed primarily on smaller fishes, which they catch either sideways in their beaks, or with an upward sweep of their heads. In addition, some species also take krill, swimming crustaceans, and small cephalopods.
Needlefishes can leap at the surface at speeds of up to 60km per hour, and some people have been injured when accidentally struck by them, particularly at night when the fishes are attracted by lights.