Murray Island bandfish

Where they come from

Owstonia merensis (Murray Island bandfish) is one of those deepwater, slope-reef oddballs that shows up from the Coral Sea area around the Torres Strait and nearby regions. They are not a "reef flat" fish at all - think dimmer light, cooler-stable water, and a life spent hovering just off the bottom where food drifts by.

That background matters because a lot of the usual "reef tank" assumptions (bright lights, heavy foot traffic, boisterous tankmates) make them shut down fast.

Setting up their tank

If you only remember one thing: build the tank around making the fish feel safe. Bandfish are hoverers that want a tight bolt-hole and calm water around it. Mine spent the first couple weeks doing the classic "peek out, grab a bite, reverse back in" routine until it decided I was not a threat.

• Tank size: bigger is easier. I would not bother under 40-50 gallons for a single fish, and 75+ if you are trying a pair or a small group.
• Aquascape: lots of rock, but with real caves and crevices you can actually see into. Make a couple narrow, shadowy hideouts, not just open arches.
• Substrate: fine sand is nice, but they are not true sand-burrowers like garden eels. The hiding spots matter more than the sand depth.
• Flow: moderate, not blasting. Give them a calmer "eddy" area near their hideout so they can hover without fighting the current all day.
• Lighting: they do better with subdued light or shaded zones. If your reef lights are intense, add overhangs and darker lanes.
• Cover: lid the tank. They can spook and launch.

I also recommend a long, boring acclimation period: dim the lights, keep the room quiet, and do not rearrange the rock after it goes in. They hate change, and they remember where "home" is.

What to feed them

They are planktivores/micro-predators. In practice that means small meaty foods, offered frequently, and ideally delivered so it drifts past their face. If food hits the sand, the faster fish will vacuum it up before the bandfish even decides to move.

• Great starters: live copepods, enriched live brine (as a transition food), small live mysis if you can get it
• Frozen staples: PE mysis (chopped if needed), calanus, finely chopped krill, enriched brine, roe/eggs
• Prepared: some will take tiny sinking pellets eventually, but do not bank on pellets as the main diet early on

Training them onto frozen is the make-or-break step. I have had the best luck starting with live foods for a few days, then mixing in frozen calanus or chopped mysis so it looks like "drifting specks." Use a turkey baster or feeding pipette and gently puff food past their hideout.

How they behave and who they get along with

They are shy, observant, and easily bullied. Once settled, they hover in the open more than you would expect, but they still want a quick escape route. Sudden movement outside the tank can send them rocketing back into the cave.

• Good tankmates: small, calm reef fish that do not compete hard for the same food (small gobies, quiet wrasses, firefish-like personalities if they are not pushy, some dartfish).
• Avoid: dottybacks, aggressive clown pairs, most hawkfish, big wrasses, triggerfish, fast boisterous anthias groups, anything that rushes the water column at feeding time.
• Also avoid: fish that will "own" the same cave system (certain basslets or territorial blennies), because the bandfish will just stop coming out.

If you are determined to keep it in a busy reef, you can still make it work, but you will be doing targeted feeds forever. I ended up turning off pumps for a few minutes, feeding the bandfish first with a pipette, then letting everyone else have the leftovers.

Breeding tips

Realistically, breeding in home tanks is rare. Deepwater perchlets/bandfish type species tend to have pelagic larvae that are tiny and demanding, and getting a compatible pair is its own puzzle.

If you want to take a swing at it anyway, your best shot is a species-focused setup: calm tank, multiple hideouts, heavy feeding, and a way to collect eggs/larvae (overflow to a larval collector or a dedicated kreisel style rearing tank). If you ever see dusk spawning behavior (pairing up, rising into the water column), you will need live plankton cultures ready, not "tomorrow."

Common problems to watch for

• Starvation from shyness or competition - the fish hides, misses meals, and slowly wastes away.
• Shipping/decompression issues - odd buoyancy, sudden decline after looking OK initially, trouble staying level in the water.
• Jumping during the first weeks - spooked fish and open tops do not mix.
• Mouth damage - they can scrape themselves in tight rockwork or during rough capture; watch for swelling or refusal to feed.
• Parasites (marine ich/velvet) - deepwater fish can crash fast; quarantine is your friend, but keep the QT quiet and dim.

My rule with bandfish: if it skips food for 2 days, I treat that like an emergency. First I check for bullying and feeding access, then I check breathing rate and body condition, then I check water quality. Most of the time the fix is simple - quieter tank, targeted feeding, and giving it a real cave it can claim.