Spadefish and Batfish, Family Ephippidae, in the Home Aquarium
Spadefish are a mixed bag as far as suitability for keeping in the home aquarium. Some species are model specimens in peaceful communities, being hardy, easy to feed, and personable. Others, are skittish and never really settle into home aquarium life. All of them are big, however, and are demanding in terms of tank space. Do you have what it takes to keep these lovely fishes?
Species
Ephippidae is one of the 6 Families under the Suborder Acanthuroidei (Order Perciformes). They are related to Surgeonfish, Scats, Rabbitfishes, and the Moorish Idol, all of which commonly are sold as pet fish.
About 20 species of fish over 8 genera have been identified for the Family Ephippidae. Though only a small number of these have been noted along the coasts of North America:
- Chaetodipterus faber (Atlantic Spadefish) [pictured]
- Chaetodipterus zonatus (Pacific Spadefish)
- Platax orbicularis (Orbicular Batfish)
Only the Orbicular Batfish is periodically sold as a pet fish in the Marine Trade, though it is extremely well suited to captive life. The other species are more often sold as food fish than pet fish.
Conservation Status
Both species of Chaetodipterus Spadefish are considered to be Stable, with an IUCN Status of Least Concern. No information is listed on the Orbicular Batfish.
Distribution
The majority of species of Spadefish are found in the Pacific Ocean, mostly in the Indo-pacific and only two species are found in the Atlantic. The Pacific Spadefish and Orbicular Batfish are sometimes found in the Gulf of California down along the Pacific Coast of Mexico. The Atlantic Spadefish has a much longer range, from as far north as Massachusetts down to Rio Grande do Sul, Brazil. They are not typically common North of the Chesapeake bay, however.
Description
Spadefish as a whole are large, deep-bodied fish. The Atlantic Spadefish tops out at about 36 inches (and 20 pounds!), while the other two species periodically reach 20-26 inches. They are also extremely tall fish, usually reaching 16 inches in height. Obviously not fish for shallow tanks.
The Chaetodipterus Spadefish are very skittish fish and never seem to adapt to life in the home aquarium. Too often to they refuse to eat or die “mysterious deaths” after doing seemingly well for a period of time. The Orbicular Batfish is another story. These fish do seem to take readily to life in the home aquarium and quickly recognize people who are food sources. They seem to imprint on the owners and have been described as “dog-like” in behavior.
Spadefish as a whole are typically peaceful to all but bite-sized fish in the home aquarium, though will consume (or at least “taste”) invertebrates in the tank and should be considered for Fish-Only systems. They are social fish, being best kept in large groups to reduce nervousness. They are also fairly smart and have been noted for being able to be trained to retrieve objects!
Feeding
Not picky at all. Spadefish which are settled in will likely consume whatever food you provide them, whether pelleted or frozen or freeze dried or live (in the case of invertebrates). The best staple food is a good quality pellet such as Spectrum, with frozen foods supplemented every so often. Spadefish also eat seaweed in the wild, so should be supplemented with green foods as well like Sushi Nori.
Water Quality
As marine fish, especially those which are found in reef settings, Spadefish are best kept in large, stable systems. High carbonate hardness, high pH (around 8-8.5), and low levels of fish waste in the water are musts. They are best kept around a Specific Gravity of 1.025-1.026. These are large fish and produce a lot of waste. Utilizing Deep Sand Beds to aid in nitrification and a working protein skimmer are HIGHLY recommended with these fish. Live Rock is beneficial as well.
Temperature depends on species, but for all should remain stable. Subtropical species will likely be fine around room temperature, but the Tropical Orbicular Batfish will all need heaters in the tank.
Brackish Suitability
The Spadefish family includes several species of fish which are brackish tolerant. As juveniles, the Orbicular batfish does best in brackish waters around 1.015, though as adults are best kept from 1.020-1.025. Likewise, juvenile Atlantic Spadefish have been noted in areas around 1.011-1.015, but as adults should be kept in full marine conditions. There is no evidence to suggest that the Pacific Spadefish can be kept in brackish conditions for any extended period of time.
Tank Size
Tanks for these fish need to be massive. The (slightly) smaller, less nervous Orbicular Batfish can be kept in tanks around the 300 gallon mark or higher in small groups. The two Chaetodipterus Spadefish will need thousands of gallons and large groups to be kept calm and healthy. This is not an easy task for the home aquarist, and as such these fish are likely best left in the Ocean or in Public Aquaria.
Breeding
These fish are not bred in home aquariums. They are thought to be pelagic spawners, breeding in large schools. The larvae develop in coastal waters and/or estuaries and return to the ocean upon maturity. All Spadefish sold in stores are wild-caught. There has been some success in breeding the Atlantic Spadefish for use as food fish, which requires hormone injections in order to trigger spawning.
Final Thoughts
Compared to Damselfish and Marine Angelfish, the North American Spadefish are not exactly colorful or as highly desired for the home aquarium. While it’s true that many of these fish are not well suited for captive life, the ones that do are wonderful additions to large Fish-Only systems and are definitely worth keeping.
Sources
Fish Identification, Fishbase
(7c) Batfishes (Platax Spp.), Neale Monks
Crazy about Batfishes, but not Spades, Family, Ephippidae, Bob Fenner
SAV and Faunal Relationships With Regard to Salinity and Seasonality, K. Burns, J, Gannon, C. Weaver, E. Estevez, A. Boyes, M. Gittler
Development of Baseline Larviculture Production Protocols for Atlantic Spadefish Chaetodipterus faber, Daniel Sennett, Michael Schwarz, Jesse Trushenski
(Image Source: Me!)
