The red-lipped batfish (Ogcocepphalus darwini) is an unusual looking fish from the Galapagos Islands. It belongs to the family Ogcocephalidae, whose members are commonly referred to as batfish.
Red-lipped batfish resemble and are closely related to rosy-lipped batfish (Ogcocephalus porrectus), which are found near Cocos Island off the coast of Costa Rica. Both fish species look and behave very similarly to one another.
There is another group of fish that are commonly referred to as batfish, but they belong to the family Ephippidae and not the family Ogcocephalidae. The name "batfish" is derived from their appearance - they are fish that are said to resemble bats.
All fish known as batfish have compressed bodies. Batfish from the family Ephippidae usually have elongated fins and laterally compressed bodies. In contrast, batfish from the family Ogcocephalidae, which the red-lipped batfish belongs to, tend to have horizontally compressed bodies and don't have elongated fins.
Although some batfish species are kept in the home aquarium, in general you won't encounter the red-lipped batfish in the aquarium hobby. Most batfish species that are kept in the home aquarium are from the family Ephippidae.
The red-lipped batfish is not considered a good aquarium fish because of its predatory nature. Also, it is a deep sea fish and so isn't commonly encountered. It usually inhabits an ocean depth of over 100 feet (30.5 m).
In addition, because this fish normally inhabits the deep sea, the lighting in its aquarium would need to be kept much darker than most aquarists are used to. In fact, they aren't often kept in home aquaria.
The red lipped batfish has a similar method of finding edible prey as the longlure anglerfish. Both the red-lipped batfish and the anglerfish "go fishing" for their dinner. Like the anglerfish, the red-lipped batfish has an illicium, which is a small extension from its head region. In the red-lipped batfish the illicium is protected by an elongated snout. Attached to the illicium is the esca that the fish uses to lure in unsuspecting prey.
See the article on longlure anglerfish to see a short You Tube video of both the red-lipped batfish and the anglerfish.
They are carnivores and their diet consists mainly of small fish and crustaceans (e.g., shrimps, mollusks, and crabs).
The red-lipped batfish is a bottom dwelling fish. To move from place to place it has modified fins that it uses to "walk" across the ocean floor instead of swimming.
It is believed that the function of the bright red lips may be to enhance species recognition during spawning.