NeedlefishesBelonidae

Needlefish have killed people, and never once on purpose. The mechanism is a collision, not an attack. Startled at the surface, or drawn in by a light at night, a fish over a meter long comes out of the water and skitters across it at speed with a beak of solid bone leading, and it does not steer around what is in the way. The documented cases across the Indo-Pacific are night fishermen working under lamps, night divers and snorkelers, and people standing in shallow water holding a light: the beak enters a chest, a neck, an abdomen or an eye, and it sometimes snaps off inside. Deaths are rare. Punctures are not, and they are treated as serious because of how deep and how dirty they are.

The precaution costs nothing. At night, keep a light aimed down into the water rather than swept across the surface, do not swim at the surface with a lamp held up, and if a boat is working under lights, expect fish to arrive on deck.

The rest of the animal is a straightforward surface predator. Both jaws are drawn out into a long beak lined with fine sharp teeth, the dorsal and anal fins sit far back where they do the most good in a single burst, and the fish takes small silver prey with a sideways sweep of the head rather than a forward lunge, which is how something with a beak catches something wider than the beak. It lives in the top meter or two of water and rarely goes deeper.

It arrives at those jaws in stages. A young needlefish has its lower jaw running well ahead of the upper, so for a stretch of its growth it looks exactly like a halfbeak, and only later does the upper jaw catch up and match it.

In several members of the group the bones are green, sometimes strikingly so. The pigment is biliverdin, a breakdown product of blood that most animals get rid of and these deposit in the skeleton. It is harmless, and it has kept a good food fish off plates in places that could use it. Four species are listed here, the largest well over a meter.