Taxonomy

Rarity

The IUCN Red List has recorded the shortnose batfish as Least Concern since 2014, but reef guides rate it very uncommon to rare across its range. A diver who finds one still counts it as a lucky day. Sightings are uncommon because the fish disappears into the bottom. It is the color of the sand it lies on, partly buried most of the time, and does not move unless it has to. It is the kind of animal a diver walks past without noticing. Encounters happen when a diver looks closely at the sand. The species is caught in a small aquarium trade in northeastern Brazil and almost never eaten. No population trend has been reported that would move its status.

Seasonality

Location

The shortnose batfish is a Western Atlantic and Caribbean animal. It lives from southeastern Florida, the Bahamas, and the northern Gulf of Mexico south through the Antilles and the western Caribbean to northern Brazil. It does not occur in the Pacific Ocean and is not found off California. A diver looking for one has to travel to the tropical Atlantic to find it.

Within that range, the fish holds to soft bottoms next to reefs rather than the coral itself. The substrate is sand, mud, coral rubble, or seagrass. The recorded depth runs from the shallows to about 1,000 feet. Individuals have been reported at depths throughout that range. Reef guides give a working depth range of 5 to 600 feet, so only the shallow end of that band is within reach of a diver, and reliable observations come on scuba rather than snorkel. Snorkelers do find the fish in the shallow flats and seagrass meadows of the Bahamas and the Florida Keys, but not often. The animal is built to walk the seafloor.

Deep Dive

The shortnose batfish is an anglerfish that barely swims. It belongs to a family of flattened, bottom-dwelling anglerfishes called batfishes, and the feature that defines the family is the fins. The pectoral and pelvic fins are thickened into short limbs with elbows and fleshy pads at the tips. The fish uses them to walk across the seafloor in a slow, 4-legged shuffle. Researchers who have studied the fins describe them as working much like the legs of a land animal, with the shoulder joint able to rotate because of the shape of the first radial, one of the small bones at the base of the fin. Batfishes will sometimes push off in a short, awkward hop, but they are not built to swim well. On flat sand or mud, a batfish covers ground the same way a toad does.

The face is the other easy tell. Above the mouth, the fish carries a horn-like knob that varies from a short bump to a long, finger-like point. Under the horn, in a small cavity, sits a retractable lure. The lure is a modified dorsal fin ray with 3 fleshy tips at its end, and the fish can push it out or pull it back in. In the closely related species that have been studied, the lure works by releasing a chemical attractant that lasts about 2 minutes and pulls small prey close enough to strike. The hunting sequence has not been directly observed in the shortnose batfish itself, so the details are inferred from its relatives. What has been recorded of its stomach contents fits the family pattern: small fishes, crabs and other crustaceans, snails, clams, worms, and occasional bits of algae.

Everything about the fish is built around not being seen. Its color ranges from dark gray to reddish brown with a network pattern of paler blotches ringed by darker edges, and the pattern matches the mixed coral rubble and coarse sand it prefers. Juveniles show a paler mottling that resembles gravel. Adults settle onto the bottom and press down until they are half buried, so what a diver's eye picks up looks more like scattered debris than a fish. The camouflage protects the batfish from predators looking down at it and keeps small prey from noticing the lure. The maximum recorded length is about 15 inches, and a typical adult is 6 to 12 inches from the tip of the horn to the tail. That is a small, still animal on a busy reef floor. A diver who spots one is usually a diver who was moving slowly and studying the sand more than the coral above it.

The shortnose batfish is not aggressive and is not dangerous to divers. It is not fished commercially in the United States and appears in the aquarium trade only in small numbers out of Ceará, Brazil. No breeding season has been described from the wild, and no group behavior has been reported. The eggs and larvae drift in open water, and juveniles settle to the bottom when they change into their adult form. Once a batfish reaches the sand, it stays there.