Cardinalfish and Other Species

Two of the fish we stock do not fit any of the other groups, and both are worth knowing about - one is among the best fish available for a smaller tank, and the other is an Australian species you will rarely see anywhere. Gallery Aquatica is in Tingalpa, east of the Brisbane CBD.

These fish are in-store purchase and pickup only. We do not send live fish by courier or freight. Ring 0420 484 584 to check what is in.

Banggai Cardinal (Pterapogon kauderni, listed as Bangai Cardinals)

One of the most distinctive small marine fish there is: silver-white with three bold black vertical bars, elongated trailing fins and scattered white spots that catch the light. Reaches 8 cm and is comfortable in around 110 litres.

They move quite unlike other fish - slow, hovering, almost hanging in the water rather than swimming through it. In a small reef tank a group of them is a genuinely striking display, and because they are so peaceful and so undemanding they suit tanks where most marine fish would be a stretch.

Mouthbrooding

Banggai cardinals are paternal mouthbrooders. The male holds the fertilised eggs in his mouth for around three weeks, not feeding during that time, and releases fully formed juveniles rather than larvae. That last detail is unusual and important: it is why this species is one of the few marine fish that can realistically be bred at home, since there is no difficult larval stage to feed through.

A brooding male is obvious once you know what to look for - a distended jaw and a fish that stops eating and keeps to itself. It is not illness.

Keeping them

Keep a pair or a group of five or more. Groups of three or four tend to go badly, because two fish pair up and gang up on the odd ones out. In a larger group the aggression disperses, much as with chromis, though cardinals are far milder about it.

They are shy at first and appreciate overhangs and shaded rockwork to hover under. Feed small frozen foods - mysis and enriched brine - which they take readily. They are slow, deliberate feeders and will be outcompeted by anything boisterous, so watch that they are actually getting food in a mixed tank.

Reef safe and completely peaceful.

Ask for captive-bred

Worth knowing: this species has one of the most restricted natural ranges of any aquarium fish, confined to the Banggai Islands in Indonesia, and wild populations have been affected by collection for the trade. It is conservation-listed as a result.

Captive-bred Banggai cardinals are widely produced and are the better buy on both counts - they are hardier, better adapted to prepared food and to aquarium life, and they take nothing from a vulnerable wild population. It is worth asking about when you visit.

Flathead Perch (Rainfordia opercularis)

An Australian endemic, found along the northern and eastern coasts, and an uncommon fish in the trade anywhere in the world. Elongated orange-red body finely striped in blue-white along its length, with a distinctly flattened head. Reaches about 15 cm and wants around 250 litres.

It is a member of the same broad family as the groupers and soapfishes, and it behaves like a small one: secretive, cave-dwelling, and content to sit in a shaded overhang watching the tank rather than swimming in the open. Give it caves and it will use them constantly.

Being a predator, it will eat ornamental shrimp and any fish small enough to swallow, so treat it as invert-unsafe. It leaves coral entirely alone. Feed meaty frozen foods.

Genuinely rarely available, so if you are after one it is worth asking us to let you know when one comes in rather than hoping to find it on the day.

Which should you buy?

The Banggai cardinal, if you want a peaceful, unusual-looking fish for a smaller reef tank - buy five or more, and ask for captive-bred.

The flathead perch if you specifically want an uncommon Australian species and have a tank without small fish or shrimp in it.

Tankmates

Banggai cardinals suit any peaceful community: clownfish, gobies, blennies, chromis, anthias, tangs and dwarf angelfish. Just make sure they are not being outcompeted at feeding time. Keep them well away from lionfish, morays and triggerfish.

The flathead perch needs tankmates too large to eat - tangs, rabbitfish, angelfish and larger wrasses. It will eat cardinals, gobies, blennies, chromis and shrimp.

Common questions

Do you ship these fish?

No. All marine fish are in-store purchase and pickup only. We do not send live fish by courier or freight.

Are they in stock right now?

These are species we stock as part of our regular range, not a live inventory, and the flathead perch in particular is only available occasionally. Ring 0420 484 584 or email shop@galleryaquatica.com.au to check.

How many Banggai cardinals should I keep together?

A pair, or a group of five or more. Avoid three or four - two fish pair off and pick on the remainder. Larger groups spread the pressure and settle better.

Why has my Banggai cardinal stopped eating with a swollen jaw?

It is almost certainly a brooding male. Banggai cardinals are paternal mouthbrooders: the male holds the eggs in his mouth for around three weeks and does not feed during that time. He will release fully formed young rather than larvae.

Are Banggai cardinals easy to breed?

Easier than most marine fish, because the male releases fully developed juveniles instead of larvae, so there is no difficult larval feeding stage. They are one of the few marine species regularly bred by home aquarists.

What size tank does a Banggai cardinal need?

Around 110 litres, which makes them one of the better options for a smaller marine tank. Allow more if you are keeping a group of five or more, which you should be.

Are these fish reef safe?

Both leave coral alone. The Banggai cardinal is completely peaceful and invert safe. The flathead perch is a predator and will eat ornamental shrimp and small fish.

What is a flathead perch?

An Australian species, Rainfordia opercularis, related to the groupers and soapfishes. It reaches about 15 cm, is orange-red with fine blue-white striping, and is secretive and cave-dwelling. Uncommon in the trade anywhere.

More marine fish

See all the marine fish we stock, or the Brisbane store page for coral and equipment.