Bradbury's batfish
Coelophrys bradburyae
Bradbury's batfish features a flattened, disc-like body, pale tan coloration, and distinctive pectoral fins that resemble wings.
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About the Bradbury's batfish
This is a tiny deep-sea batfish from off Japan that basically lives down in the dark on the seafloor, using a little lure (like other anglerfish relatives) to help it hunt. It is super obscure - the original description was based on a single specimen from about 557-595 m deep, so there just is not much biology or aquarium info out there.
Also known as
Quick Facts
Size
5.8 cm
Temperament
Peaceful
Difficulty
Expert
Min Tank Size
0 gallons
Lifespan
unknown
Origin
Western Pacific (Japan)
Diet
Carnivore - unknown in detail; likely small benthic crustaceans/worms
Care Notes
- Give it a big, mature sandbed (fine sand) with low flow and lots of open bottom space - these batfish are sit-and-wait hunters and hate being blasted around.
- Keep salinity steady at 1.025-1.026 and temp around 74-78F; they do way better with stability than chasing some magic number, so use an ATO and don not let salinity swing.
- They are picky and lazy feeders at first - start with live foods (ghost shrimp, small shore crabs, live mollies acclimated to salt) and then wean onto thawed silversides, shrimp, or squid on feeding tongs right in front of the lure.
- Feed smaller portions more often (every other day or so) and watch the belly - they will gorge and then sit, and fatty foods can wreck them if you overdo it.
- Tankmates need to be calm and not food-competitive: avoid wrasses, triggers, puffers, and anything that will steal food, nip the lure, or crawl over it; slow, non-aggressive bottom fish are the only semi-safe picks.
- Cover intakes and overflows - they can wedge into weird spots and get pinned by suction, especially when they are stressed or newly introduced.
- Red flags: torn lure/filaments, cloudy eyes, rapid breathing, or refusing food for more than a couple weeks; most losses come from shipping damage plus starvation, so quarantine and get it eating early.
- Breeding in tanks is basically a lottery - they are deepwater/spawn-in-the-water-column types, so do not buy one expecting babies; focus on long-term feeding and keeping stress low.
Compatibility
Good Tankmates
- Small, chill sand-sifters like a Yellow Watchman Goby (Cryptocentrus cinctus) - they mostly mind their own business and wont hassle a sit-and-wait batfish
- Other peaceful gobies (neon gobies, clown gobies) - calm, not bitey, and usually smart enough to stay out of the mouth-sized danger zone
- Dragonets like a scooter blenny/dragonet (Synchiropus) - peaceful and slow, and they cruise for pods instead of picking on weird-shaped fish
- Firefish (Nemateleotris) - gentle open-water types that dont spend their day inspecting and pecking at everything on the bottom
- Tiny, well-behaved blennies like tailspot blenny (Ecsenius stigmatura) - generally peaceful and not the fin-nipping, bully kind
- Cleaner shrimp (like skunk cleaners) and small, non-predatory inverts - batfish are ambush hunters, but they usually ignore cleaners and you want tankmates that wont harass them
Avoid
- Hawkfish (flame hawkfish, etc.) - they perch and pounce, can be pushy, and they love picking at slower, weirder fish and stealing food right off the bottom
- Dottybacks (pseudochromis) - classic small tank terrors, super territorial, and they will absolutely stress a peaceful, sedentary batfish
- Aggressive or nippy wrasses (sixline, some halichoeres) - constant motion, constant attitude, and they can harass or outcompete the batfish at feeding time
- Triggers and puffers - too curious and too bitey, they tend to harass oddball bottom sitters and can take chunks out of fins or spines
Where they come from
Bradbury's batfish (Coelophrys bradburyae) is one of those deepwater oddballs that looks like it was designed by committee. They are collected from deeper slopes and seamount-y habitats where the light is low and food is hit-or-miss. That deepwater origin drives almost everything about how they handle captivity: they do not like bright, busy reef tanks, and they do not handle shipping stress like a hardy clownfish would.
This is an expert-only fish for a reason. Most losses happen in the first few weeks from shipping damage, starvation, or infections that show up after the stress of collection.
Setting up their tank
Think of this fish as a sit-and-wait ambush predator that wants a calm, dim corner and stable water. Give it space on the bottom, lots of low caves/overhangs, and no sandstorm flow. The fish is not built to compete, and it will not appreciate you blasting it with reef-level light and current.
- Tank size: I would not do one in anything smaller than 40-50 gallons, and bigger is nicer for stability. They do not need swimming length, they need stable conditions and a quiet footprint.
- Aquascape: broad ledges, caves, and shaded pockets. Leave open sand or a flat rock area where it can perch and hunt.
- Substrate: fine sand works, but keep it clean. Detritus piles around these guys fast because they sit in one place.
- Flow: low to moderate, but break it up. You want gentle movement, not a powerhead pointed at its face.
- Lighting: subdued. If you run strong lights, create shaded zones with rockwork and consider a shorter photoperiod.
If you can, start with a tank that has been running a long time and has a mature pod population. Even if you plan to train it to frozen, that early "something is always moving" food availability can buy you time.
Water parameters are just standard marine reef ranges, but the real trick is avoiding swings. Keep salinity steady, keep nitrate reasonable, and do not let oxygen drop at night. Deepwater fish can react badly to sloppy aeration, especially in warm rooms.
Cover the tank. Batfish can lunge and scoot, and stressed new arrivals sometimes end up on the floor even though they are not classic jumpers.
What to feed them
Feeding is the whole game with Coelophrys. A lot of them arrive thin and they do not recognize pellets or flakes. You are basically teaching a weird, sedentary predator that dead stuff on tongs is food. Some learn. Some never do.
- Best starter foods: live ghost shrimp, small live marine shrimp, live blackworms (if you can source clean ones), and sometimes live mysis.
- Transition foods: thawed mysis, chopped raw shrimp, pieces of squid, and small strips of fish flesh (not oily, not seasoned).
- Feeding method: long tongs or a feeding stick right in front of the mouth, with the pumps paused so the food does not blow away.
- Frequency: small offerings daily at first. Once it is taking frozen reliably and has some weight, you can shift to every other day.
I have the best luck feeding right after lights dim. They often act more confident in lower light, and you are not fighting daytime tank bullies.
Watch the belly. A batfish that is not gaining weight is on a timer. Do not assume it is eating just because food disappears. Tankmates and cleanup crews will steal meals fast.
How they behave and who they get along with
They are basically living furniture with teeth. Most of the day they sit, blend in, and wait. The "lure" (their little fishing rod) is real, and they will use it if they are comfortable. They are not aggressive in the chasing sense, but anything that fits in the mouth is potential food.
- Good tankmates: calm, non-competitive fish that will not harass it and will not steal every bite (think small, peaceful species that stay in the water column).
- Bad tankmates: fast feeders (wrasses, anthias), nippy fish (some angels, triggers), and anything that perches on it or picks at skin (some hawkfish).
- Inverts: expect it to eat small shrimp and tiny crabs if it can catch them. Large cleaner shrimp sometimes survive, but do not bet on it.
Do not mix it with small gobies, blennies, or tiny cardinalfish unless you are fine with them turning into dinner. If it fits, it is food.
They do best as a feature fish in a species-leaning setup. A busy community tank is usually a slow-motion failure: the batfish loses meals, stays stressed, and you are left wondering why it is fading.
Breeding tips
Realistically, breeding Bradbury's batfish in home aquariums is not something most of us can plan for. Deepwater anglers and batfish have complicated spawning behavior, and even sexing them is not straightforward. If you ever keep two that tolerate each other, consider it luck, not a repeatable recipe.
If you do observe courtship or egg release, document everything: temperature, photoperiod, moonlights, feeding schedule, and time of day. For rare fish like this, good notes are genuinely useful to other keepers.
Common problems to watch for
Most issues with this species come down to three things: they arrive damaged, they do not eat, or they get infections after stress. They can look "fine" while actually declining, so you have to be a little paranoid in a good way.
- Starvation: hollow belly, pinched look behind the head, weak response to food. Act early with live foods and target feeding.
- Shipping/stress damage: torn fins, abrasions on the belly, red patches. Keep lighting low and avoid handling.
- Bacterial infections: redness, cloudy patches, fin rot, ulcers. These can escalate fast in a stressed deepwater fish.
- Parasites: heavy breathing, flashing, excess mucus. Quarantine is tough with reluctant eaters, but skipping it can burn you.
- Low oxygen/high heat: rapid breathing and lethargy, especially at night. Add surface agitation and keep temperatures steady.
Be careful with copper and other harsh meds. If you have to treat, do it with a plan and close observation. These guys are not forgiving, and appetite usually gets worse under medication.
The single best "quality of life" move: give it a calm feeding zone. Turn off pumps for a few minutes, use a feeding stick, and do not let cleaner shrimp or hermits mob the food before the batfish commits.
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