No Laughing Matter:Taiwan Races to Save the Clownfish

"Walking down Taipei's 'aquarium street' a few days ago, I saw colorful fish of all kinds: blue tang, clownfish, and damselfish," laments Ho Yuan-shing, an assistant researcher with the FRI's Eastern Marine Biology Research Center (EMBRC), on his website. "All of them probably came from Southeast Asia. Fishermen bring them to the surface by poisoning the water or netting them."

"In the ocean, clownfish elicit coos of delight, but keeping them in a poorly maintained aquarium is a death sentence for the fish. Leave them be! Don't kill any more of them!"

The Eastern Marine Biology Research Center has successfully bred blue tang-the same species as Dory in the film Finding Nemo-but so far hasn't found a way to mass produce them.

Some 95% of the world's aquarium fish are thought to have been captured in the wild, and aquarium market demand for clownfish is likely to determine the fish's ultimate fate in the Pacific and Indian Oceans. "People are eager to buy them, so fishermen are eager to catch them," says Ho, explaining that these little Nemos are the world's third most demanded aquarium fish and account for 15.6% of the trade.

Taiwan is surrounded by a sea filled with all manner of corals and sea anemones. At one time, our waters were a paradise for clownfish, but in recent years their numbers have plummeted in the seas off the northeast and east coast, Kending, and Penghu. Suppliers of aquarium fish have therefore turned their attention to Southeast Asia, where the fish still abound.

But capturing clownfish is extremely detrimental to marine ecosystems. Clownfish live in symbiosis with poisonous sea anemones, which protect them and make them difficult to catch. Fishermen therefore use cyanide to stun the fish, then scoop them out of the water. Other species of fish hit by the poison, who are not moved to untainted water, simply don't "wake up." Typically more than 10 fish of other varieties are killed for each clownfish captured.

These captured clownfish are not fed during their one-week trip to Europe or the US, and may suffer impacts, fright and injuries on the way. As a result, usually just one-tenth arrive alive. Most that make it to a shop are in poor shape.

EMBRC began studying clownfish reproduction nine years ago, but that it began at all was largely a fluke.

EMBRC had opened an aquarium in Chenggong Township, Taitung County, in 2002. Then one day Ho happened to notice a large number of clownfish eggs in one of the tanks, and leapt at the chance to study clownfish reproduction. He had no way of knowing that Finding Nemo would catapult the clownfish to global popularity just one year later, and make his serendipitous research enormously topical.

Cheng Ming-jong, a researcher with the Fisheries Research Institute, is testing the effects of water pH and oxygenation on fish fry.

Because wild-born aquarium fish are still relatively plentiful and cheap, there has been little research into assisted reproduction of clownfish. Domestic and foreign commercial fish fry companies only develop breeding and rearing techniques for high-demand, high-price species. Moreover, they consider the techniques they have developed to be trade secrets.

Ho needed help overcoming difficulties related to establishing mating pairs and increasing the frequency with which the fish lay eggs. With little information from commercial research and development publicly available, he had to rely entirely on fish breeding techniques EMBRC had developed over the years. His goal was to adapt these techniques to allow him to produce large volumes of clownfish fry.

The first step was getting males to mate with females. He found that they need a quiet environment where they will not be disturbed. Moreover, sea anemones and coral are also essential. "Each species of clownfish lives in symbiosis with a specific species of anemone," explains Ho. "For example, ocellaris clownfish live in symbiosis with only three species of anemone: Heteractis magnifica, Stichodactyla gigantea, and Stichodactyla mertensii."

Clownfish are sensitive and very territorial. Only three to five clownfish live in a given sea anemone, and there is no guarantee that they will pair up. If they take a dislike to one another, they are likely to fight over territory and end up injuring one another.

EMBRC researchers therefore placed each male-female pair in a tank of its own, ensuring that the pairs were together all the time and thereby increasing the odds of mating success.

The temperature and quality of the water in the "maternity ward" were also crucial. Researchers tested the effects of variables one by one. They discovered that when they controlled the pH and the concentrations of nitrous acid and ammonia, egg production was highest with nine to 12 hours per day of light at 20,000 lux, a water temperature of 26° to 28°C, and a salinity of 33-35 parts per thousand.

Researchers also observed that certain signs indicated when clownfish were preparing to breed for the first time.

On their first reproductive cycle, the female clownfish would first choose a spot on coral next to a sea anemone. They would then spend the two to three days prior to laying their eggs removing algae and sediments from the site, sometimes using their tails to sweep away small stones. This behavior was more frequent as laying approached, and stopped only when laying began. On subsequent reproductive cycles, the fish only exhibited this behavior for two to three hours prior to laying their eggs.

Relying on its previous experience hatching saltwater fish and on close observation, EMBRC worked out the keys to breeding in captivity in just six months, enabling it to increase the frequency with which its clownfish laid eggs from five or six times a year to more than 20.

Young clownfish can be packaged and sold at 60 days old, when they are about two centimeters in length.

Research shows that clownfish embryos usually begin to hatch about half an hour after sunset. Light interferes with the hatching, so it is best if it takes place in a pitch-dark environment. "Anemones retract their tentacles at this time, so the just-hatched fry are safe from stings and injuries," explains Cheng Ming-jong, an FRI researcher.

The newly hatched fry are just 0.3-0.4 centimeters in length, their black eyeballs the only easily visible part of their otherwise transparent bodies. The fry are also phototactic, enabling researchers to use an LED light to gather them together and move them to another tank.

Ho says that the larvae's small size makes them vulnerable, and they die at a greater rate than the adult fish. In the wild, their survival rate is less than 0.1%. One of the keys to rearing clownfish fry is finding foods that increase their survival rate. EMBRC developed rotifer, copepod, and brine shrimp feeds for different stages in their development and has succeeded in raising the survival rate for assisted-reproduction larvae to 10-15%.

Controlling parasites was another nut to crack. Changes of season and passing typhoons create large differences between day and night temperatures that make it easy for parasites like marine ich and marine velvet to infect and kill the larvae. The larvae do best when summer water temperatures stay under 30°C and winter temperatures remain above 24°C.

EMBRC has developed techniques for mating, egg laying, hatching, and creating fish fry for five species of clownfish found in Taiwan's waters (ocellaris, tomato, pink skunk, saddleback, and banded clownfish) and 10 species found elsewhere (including black and white ocellaris, akindynos, and yellowtail clownfish).

This means that Taiwan has developed reproductive techniques for more clownfish species than any other of the small number of nations engaged in such research, including the US, the UK, Thailand, and Denmark.

A yellowtail clownfish, native to Oceania.

With reproductive technology in hand, it is now possible to consider applying it to saving clownfish in the wild.

Ho says that we need to survey the distribution of clownfish and sea anemone species, and the available resources (algae, crustaceans, and mollusks) in the waters around Taiwan before we can evaluate the feasibility of conservation zones. Over the last two years, TFRI divers have conducted several test releases of fish in the waters off the east coast and recorded tracking data.

But can these small test releases, which involve just 10 or 20 fish each, restore clownfish populations? Ho says that ecologists have doubts about the effectiveness of even large-scale releases. They argue that assisted reproduction produces too little genetic diversity, making it possible for a pathogen to wipe out the entire population.

But others disagree. They argue that the ocean breaks up groups of freshly hatched clownfish, carrying some north to Japan on the Kuroshio Current and others south to the Philippines. Batches released by humans will not end up reducing genetic diversity because they will be widely distributed and mate with a variety of other groups.

How to go about restoring clownfish to the environment may be under debate, but there is widespread agreement on the use of clownfish bred in captivity to supply the aquarium market and reduce the capture of clownfish in the wild.

But meeting aquarium market demand requires that the fish be produced in volume. The EMBRC therefore established Taiwan's first clownfish fish fry production facility in late 2008. The facility integrates everything from rearing of stud fish, mating, and egg-laying to packaging of live fish fry for transport.

Since last year, these techniques and production processes have been transferred to two companies: Azoo and Gentle Castle. Negotiations are currently underway with three others.

"Transferring technologies to the private sector, which can then ramp up production to supply the aquarium market, is equivalent to conservation," says Ho, who notes further that fish bred in captivity have an easier time adapting to artificial environments and feed, and therefore have a 60% higher survival rate in aquaria than fish born in the wild.

Black and white ocellaris are very expensive, selling for about NT$1,000 each.

Clownfish have real market value. A single two-centimeter-long fish sells for NT$50-100, and prices can go much higher depending on species, rarity and demand. For example, while common ocellaris go for NT$150-300 each, the rarer black and white ocellaris sell for about NT$1,000 each.

The industry estimates that mass production of clownfish-including investment in related businesses-will be worth upwards of NT$100 million per year to Taiwan.

"Assisted reproduction technology is still in its early stages," says Ho. "There isn't much competition. If Taiwan's fisheries businesses are the first to develop an operating model, they could become the world's largest provider of fish for saltwater aquaria and claim a significant share of the US$1.5-billion global market."

In recent years, the European Union has mulled a ban on the importation of live wild fish. If implemented, such a ban would greatly increase the demand for aquarium fish bred in captivity. In such circumstances, Taiwan's first-in-the-world clownfish breeding technology represents a tremendous opportunity.

A Maldive clownfish protecting its eggs.