Flathead Perch - How an Unobtainable Fish Became a Captive Bred Aquarium Fish

Fifteen years ago, the Australian Flathead Perch was so rare that the handful of wild specimens to reach the trade sold for thousands of dollars, up to $8k, and even scientists knew remarkably little about it. Todd Gardner, one of the world's most accomplished marine fish breeders, fell in love with this oddball species and was determined to culture it. After years of hard work, he raised the first Flathead Perch ever bred in captivity. Today, as manager of Biota North Carolina, he and his team are making this once unobtainable fish available to everyday reefkeepers for a fraction of what it used to cost.

A fish that lived in books

For a long time, the Flathead Perch was what reefers call a "book fish," a species you know exists but never expect to see outside the pages of a reference guide. It comes from the coral reefs of eastern Australia, has a limited range, and is so secretive that even divers rarely spot one. 

Science didn't know much more about this fish than the hobby did. Before 2016, everything published about its larvae came from just two settlement stage larvae caught in a light trap off Queensland in 1999. It shares a family with the groupers and basslets in the family Serranidae, as a close relative of the Liopropoma basslets, and it's the only species in its genus.

When wild specimens did trickle into the trade, the fish was worth more than a used car. In 2011, "Lemon" Yi-Kai Tea named it Reef Fish of the Year, even though almost nobody could actually get one. That same summer, Reef Builders called it "one of the rarest reef basslets ever documented in the aquarium hobby" and reported that shops in Japan sold a wild caught Flathead Perch for ~$8K. When LiveAquaria finally offered one to American collectors in August 2011, the price tag was ~$5K (Reef Builders, 2011). For the vast majority of reefers, the fish was completely unobtainable.

So how did it end up in your tank?

This is where Todd Gardner comes in. If you've spent any time researching marine fish breeding, you know the name. Todd is one of the most accomplished marine fish breeders in the world: a commercial aquaculturist at C-Quest back in the 1990s, MASNA Aquarist of the Year 2012, and the first person to breed Gramma dejongi. He had also already bred basslets like Gramma and Liopropoma, rare skills even within the tiny niche of marine aquaculture.

Todd was he was confident he had the ability to breed and raise its difficult larvae. In 2016, an anonymous donor (with help from Fluid Dynamics International and Kevin Kohen at LiveAquaria) gave Todd an adult pair that had already lived in captivity for about five years. He set them up in his lab at Suffolk County Community College, where his students helped care for them, and the pair started spawning.

Flathead Perch Egg

Getting eggs turned out to be the easy part. The larvae hatch unable to feed, then, similar to the Lipropoma Todd previously raised, grow a dorsal filament that eventually stretches to about 20 times their body length (probably to mimic deep sea siphonophores, which is about as cool as larval fish get). They need specific live copepods and phytoplankton which take experience and skill to produce. The first batch died off steadily day after day, and the losses spiked at flexion and again at settlement, when those long filaments naturally snap off. From a batch of roughly 1,000 eggs in July 2016, about 20 fish made it through settlement. That's 2%.


Flathead Perch 35DPH 

Twenty fish. That's what all that dedication bought, and it was enough. When Todd wrote up the project in 2017, he described it as "the first and only successful rearing of R. opercularis to date." Preserved eggs and larvae from the project also went to the Smithsonian to help fill in gaps of what science knows about this species. You can read Todd's full account in his 2017 article on Reefs.com.


59DPH with filament

60DPH after filament breaks off

Where does Biota come in?

Todd's Flathead Perch story didn't end in 2017. He knows that being the first to raise a species is a big deal, but it matters even more to the hobby and to advancing aquaculture to have a plan for getting that species into commercial production. That's Biota's specialty. Around 2019, he joined The Biota Group when we launched our partnership and production facility with Carteret Community College in North Carolina. Today he manages Biota North Carolina and teaches aquaculture at CCC, and the Flathead Perch is one of the fish his team raises. It's still one of the most difficult fish we produce. The larvae haven't gotten any easier, and that's a big part of why this fish is still scarce, still pricey, and still sells out.

But here's the thing. A hardy captive bred Flathead Perch, already eating prepared foods, is now something a regular hobbyist can actually buy, for a fraction of what a wild one cost in 2011. 


7 month old Flathead Perch

Is it ugly?

Every so often, someone sees a photo of our Flathead Perch and asks why we'd bother breeding such a plain little fish. Short answer: it isn't plain at all. The fish you usually see in our posts are juveniles, and juveniles don't have their adult coloration yet. At that stage they're mostly brown with a thick black stripe down the side (which, fair enough, isn't the flashiest look). Grown up, the Flathead Perch (Rainfordia opercularis) is a whole different animal: bright orange with aqua stripes, and genuinely striking. Our juvenile photos really don't do this fish justice.


Changing juvenile


Getting close to adult coloration

We get why it isn't for everyone, though. It's shy and spends most of its time in the rockwork, but once it gets used to its territory, it becomes a lot more confident. It doesn't often come out into the light, so be sure to give it plenty of caves and rock overhangs. Come feeding time, though, it'll venture out (sticking to the shady areas, of course) and beg for food with the best of them. It's also expensive, it's still scarce, and it needs very large, peaceful tankmates [it isn't aggressive, but can eat anything its own size or smaller because of its huge mouth], so it isn't a fish we'd recommend to every reefer. That's okay. Not every fish has to be for everyone.

Even though it is obtainable now thanks to captive breeding, the Flathead Perch is still a pretty scarce fish. Very few people have ever seen one in real life. This isn't something you'll see at a typical pet shop, and you have someone who has one to see it. It also needs a particular setup, so not every system makes a good home for one. All of which means that if you do get one, it comes with MAJOR bragging rights.

We're not bothered when someone calls this fish ugly or boring. If anything, we take it as a compliment. Fifteen years ago, almost nobody could have an opinion about the Flathead Perch, because almost nobody had ever seen one. The fact that an everyday reefer can now look at it, shrug, and say "eh, not for me" is proof of just how far our work with this species has come.

That's what aquaculture is supposed to do. It takes a fish that lived in books and puts it within reach of anyone who wants one. Not everyone will, and that's fine. But for the people who've been waiting a decade or more to keep this little Australian oddball, it's a dream come true.

Photos by Todd Gardner, last photo by Felicia McCaulley