A tiny deep-sea anglerfish inside a balloon of loose transparent skin, and one of the rarest things a blackwater dive returns.
A small rounded fish carried inside a much larger envelope of loose, inflated, transparent skin, so that the animal in a frame is mostly empty space with a dark core. The fins are small and rounded, there are no pelvic fins at all, the mouth is large for the head, and pigment is limited to a few dark patches over the gut and the top of the body. Females carry a short bud on the snout that will become the illicium; males have large nostrils, no lure, and jaws already modified into the denticles they will use to attach to a female.
The inflated skin belongs to the larval stage and is lost at transformation. The larval frogfishes, which have their own entry, carry a similar baggy envelope and are the animal a ceratioid is most often confused with in a photograph; frogfish larvae have limb-like pectoral and pelvic fins held out from the body, and a ceratioid has no pelvic fins to hold out.
The adults live in the deep sea and are not met by divers. What comes up on a blackwater dive is a larva that has drifted into the upper water, and this is a rare catch even at the sites where blackwater diving is run regularly. The families involved — among them Melanocetidae, Oneirodidae and Himantolophidae — are separated on characters a photograph of a larva will not give, so records are kept at the suborder.
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.
