Batfishes are beautiful, but extremely difficult to keep saltwater fish. They really are something else, but so many of them just don't make the transition from the wild to the home aquarium. They are members of the "Family Ephippidae". These members are shy, retiring, and mouthbrooders. The family has 7 genera and 20 species, found in the Atlantic, Indian and Pacific Oceans.
The body of Batfishes is flattened sideways. The mouth is small. Adults are silvery and rather squarish. Hence their other common name of Spadefish. Juvelines may look very different in colour and pattern and have very elongated dorsal and anal fins. Those seen 12-15cm long. The species are difficult to distinguish without examination of small body parts.
As high finned fishes they need a lot of space, especially in height in an aquarium what in a standard reef aquarium not can be offered (with the exception of specially for Batfishes prepared aquariums). The diet of Batfishes consists mainly of plankton, algae, small fishes, jellyfish, worms, and other small invertebrates.
Batfishes are passive, and not compatible with same or like species. They may also have problems with other fish, since they are slow swimming and other fishes often tend to nip at their fins. They have the best chance of survival if kept alone. In most cases Batfishes are not reef compatible.
They frequently appears in the aquarium-trade but it's probably better left in nature as very few survive for any appreciable time in captivity.