A slender fanged mid-water fish that hangs still in the beam and rarely leaves it.
A long, thin, cylindrical fish with a pointed head, a jaw carrying a few large depressible fangs among smaller teeth, small pelvic fins set well back, and an adipose fin. Young ones are largely transparent with a line of dark pigment blocks along the gut and are among the more ghostly things in a beam; older ones turn silvery. Most seen are between 5 and 25 cm, though the family runs larger. Needlefish and halfbeaks are surface fish with beaks and no adipose fin; the ribbonfish, which has its own entry, is deep and compressed with red fins; a leptocephalus has neither fins nor teeth. Identification is at the family. The genera — Lestidiops, Lestrolepis, Paralepis, Macroparalepis and others — are separated on fin ray counts and on internal characters, and this entry is pitched accordingly.
They are mid-water predators of fish and crustaceans, built light: a reduced skeleton and a watery body keep them close to neutral buoyancy without a functional swim bladder in many species. Like most of what a blackwater dive meets, they migrate upward at night and are in the upper layers only while it is dark.
The usual way one is noticed is that it does not move. A barracudina will hold position in the beam at a steep angle, head up or head down, and allow a close approach, which makes it an easier photographic subject than its speed would suggest. That stillness also means one can sit in a diver’s light for some minutes and be logged as several different animals.
Ratings are per location: 1 means found on most dives that look for it, 5 means a handful of records. Where enough dives have been logged the figure is calculated from them; otherwise it is an editorial estimate, and says so. We publish habitat and destination, not the dive site.
