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Fish Tale

By Cindy Spence

Research at UF's Tropical Aquaculture Laboratory is vital to Florida's $50 million ornamental fish industry

Walk into any restaurant or office building with an aquarium and there’s probably a smudge on the glass where a nose pressed against it, the better to watch the underwater world within. Maybe the observer is still there, wide-eyed and smiling.

What’s not to like? An aquarium opens to our inspection a world usually hidden from view: colorful coral, swaying plants, fish of every hue and stripe. A sharptoothed eel might lurk in a rocky opening as serene clownfish flit by. A seahorse or two, posed in a spiny question mark, might swim nearby as the ubiquitous housekeeper, the algae-eater, cleans the glass. It’s the world of Nemo, come to life 10 gallons — or 100 gallons — at a time.

It’s a hobby that can start with a goldfish in a plastic bag and grow into an obsession.

Craig Watson has known that obsession since he was 8 years old and stocked his first aquarium. Four decades later, as director of the University of Florida Tropical Aquaculture Laboratory in Ruskin, Watson has several hundred aquaria, and he never tires of pressing his nose up to the glass.

“There’s always another fish, and to see it for the first time, it’s exciting,” Watson says.

Science is the key to modern tropical aquaculture. Science has produced the world’s first patented fish. It can make the nondescript female swordtail sprout a flashy tail like the male. And science can get a species to spawn that has never spawned in captivity before.

Advances in science advance the industry, too. A regular female swordtail fetches perhaps 15 cents. Gussy her up with an actual sword-shaped tail, and she fetches 25 to 30 cents. For the female swordtail — and the farmers who trade in swordtails — looks are everything, and the UF laboratory stocks and studies some of the flashiest fish around.

“It’s hard to put into words how valuable this facility is to the industry,” says Marty Tanner, president of the Florida Aquaculture Association.

Industry Godsend

Watson’s dad gave him his first aquarium at the age of 8. By 16, Watson was working at a tropical fish farm in Miami, back when the industry was clustered in South Florida. In college he worked in a pet store until he found himself with a biology degree and no job. He worked for a tropical fish wholesaler in Riverview until the Peace Corps sent him to a hatchery in Tunisia for three years. After his return to the United States and another degree, he heard about an opening working with ornamental fish at the UF Cooperative Extension Service office in Hillsborough County.

“I spent nine years as an extension agent, answering any question anyone came up with,” Watson says. “In 1990, I realized we had extended what we knew, and we needed to do some research.”

Shortly afterward, a National Weather Service site in Ruskin showed up on a government surplus property list. Next door, a 6.5-acre fish farm was for sale. UF won a $500,000 grant from the Florida Department of Agriculture and Consumer Services to renovate the building and farm.

By 1997, the UF Tropical Aquaculture Laboratory was in business.

From these modest beginnings, the laboratory has become a powerhouse for tropical aquaculture research with a $1 milliona- year budget and 13 active projects. Researchers at the lab work closely with tropical fish farmers.

“We’ll ask them, ‘What are we missing? Is there a fish you’d like us to look at?’” Watson says.

While hobbyists wouldn’t think of taking a sick guppy to the veterinarian, tropical fish farmers often consult veterinarian Roy Yanong and sometimes bring tiny patients to diagnostic lab manager Debbie Pouder. Recently, Pouder helped a farmer who recognized and treated a primary infection in his fish, but couldn’t cure them until the diagnostic lab pinpointed a secondary infection.

Being surrounded by farms and understanding the business helps her help the farmers, Pouder says.

“A pure academic might tell a farmer to give a fish an injection,” Pouder says. “Here, we understand the farmer may well have 20,000 of those fish, and an injection is not so simple.”

Fish get sick just like people, and when they do, they need the right medicine, Watson says, so the lab conducts research that may give farmers access to more drugs and chemicals. Many used in other areas of agriculture might be useful for fish farmers, but first they must meet Food and Drug Administration standards for use in minor species.

“The FDA likes to match one drug with one species,” Watson says, “but I’m working with 500 species, so that doesn’t work.”

For their part, farmers credit the UF lab with a large measure of their success.

“That laboratory is the greatest thing since the wheel,” says Dave Rawlins, of Rawlins Tropical Fish in Lithia. “It’s a godsend to the industry.”

Small Ponds, Big Business

In a region where agriculture is usually defined by rolling hills of citrus as far as the eye can see, aquaculture is almost invisible to the casual observer, because one small pond can hold thousands of fish, even different species, and represent an investment of $20,000.

“Fish farming on a per-acre basis is one of the highest-value crops,” Watson says. “In tropical fish, you measure production by the square foot, not the acre.”

More than 85 percent of Florida’s tropical fish farms are in Hillsborough County. Membership in the Florida Aquaculture Association ranges from 150 to 180 farms, including many that raise food fish like catfish, tilapia and clams, says Tanner, who owns Aquatica, a company with three area farms.

Although sales dipped following the hurricanes of 2004 and 2005, the USDA still found that aquaculture racked up sales of almost $75 million in 2005. Of those sales, more than $33 million were in ornamental fish and more than $17 million in aquatic plants. The high value of the crops is evident when you consider the size of the farms: only nine had 50 or more acres in production and by far the majority — 185 — had fewer than three acres in production.

Because of the farms’ small footprint, fish farmers don’t feel the same pressures larger landowners do from developers, but they are feeling pressure from foreign competition.

While Florida is the nation’s tropical fish tank, accounting for 95 percent of all ornamental fish produced in the U.S., that’s only a fraction of total ornamental fish sales, with imports accounting for two-thirds of the market.

Fish farmers in places like Malaysia, Indonesia and Mexico don’t face the same level of regulation as their Florida counterparts, from drugs to treat sick fish to farming conditions. The lab’s researchers try to help level the playing field, Watson says.

The hottest thing to hit the aquarium market lately is the world’s first patented ornamental fish, the GloFish®. The fish is “manmade,” and that has sparked enough controversy to keep the GloFish® out of some pet stores. Pointing at an aquarium filled with zebra fish sporting a pinkish-reddish color, Watson says the GloFish® is a good tool to further the debate about genetic engineering.

The GloFish® was originally developed in Singapore as a tool to quickly assess water quality. A regular zebra fish is white with black stripes. When fluorescent genes from anemones are inserted into the zebra fish embryo, however, those genes are expressed in the color of the fish. The genes are heritable, too, meaning the genetically modified zebra fish can pass on its fluorescent red, green or orange color to its offspring. The company licensed to sell the fish in the United States has funded UF research to determine whether the GloFish® can be made sterile, so far without success.

The novelties in the laboratory don’t stop with the GloFish®.

There’s the archer fish, which can spit a drop of water at a bug on a ceiling or branch, knocking the creature off its perch and into the water to become dinner. Native to Malaysia and Australia, the fish has drawn attention from scientists interested in finding out how it focuses that lethal drop of water.

Then there’s the puffer fish. From its unprepossessing name, you wouldn’t guess that it is highly evolved, but the puffer genome is compact, with only about 365 million base pairs, compared to about three billion for humans.

“The puffer fish has the shortest, cleanest, most truncated genome of any vertebrate animal,” Watson says. “This animal is missing all the genetic garbage most animals have, and we’re interested in how that came about.”

From the Amazon, there is the black ghost knife fish, which is almost blind but can navigate and mate using the waves produced by an electrical organ in its tail.

The only Florida native the laboratory is studying is the mosquito fish, which due to its appetite for mosquito larvae also has the widest global distribution. The tiny fish — about half an inch long — also is an effective predator and will gang up on bigger fish, eating them piece by piece.

Another oddity is the mangrove killifish, whose northernmost distribution is Tampa Bay. The fish is the only self-fertilizing hermaphrodite in the vertebrate world, with ovaries and testes in each fish.

Then there are the popular swordtails, which are participating in methyl testosterone tests to masculinize them, thereby getting females to produce the male’s trademark swordtail.

Reproduction gets a lot of attention, Watson says, because producing fish in the United States, as opposed to importing them, saves money. It also allows a farmer to control conditions.

Fire eels, for instance, can fetch $200 in a pet shop. But they need to be caught in the wild in Southeast Asia, imported, then observed to ensure they are healthy before they can be sold and placed in a home aquarium.

If researchers can figure out how to breed fire eels domestically, they can raise them on farms, under controlled conditions, ensuring their health, Watson says.

The laboratory doesn’t do much research on saltwater species, which make up only a small fraction of the market, but Watson and his colleagues have had success recently with one saltwater sea creature — coral.

Watson said the prevailing opinion was that greenhousegrown coral could not be transplanted successfully into the wild. Researchers at UF, the Mote Marine Laboratory in Sarasota and the Florida Aquarium in Tampa, however, raised seven common corals in greenhouses and transplanted them to the Florida Keys National Marine Sanctuary to repair a damaged reef.

In a dive last year, the researchers checked up on the experiment and, so far, the lab-rat corals are healthy. The project has won another round of funding to study techniques to attach live coral to reefs and more lab corals will be transplanted this summer. The project was also recognized by the environmental organization Coastal America.

Exotic vs. Invasive

For hobbyists, the more exotic the fish or plant the better. But with 99 percent of the aquaculture industry based on nonnative species, exotic traits pose issues. Some invasive species in Florida can be traced to home aquaria that were dumped in Florida waterways, says Jeff Hill, who came to the lab in 2006 to study invasion ecology.

Like Watson, Hill got into tropical fish as a boy. Later, he bought a fish farm, which he sold to go to graduate school. With firsthand knowledge of both the aquaculture industry and science, Hill is in a unique position to balance the two.

“People always assume there’s a negative effect from nonnative species, but it’s not always negative,” Hill says. “I’m very interested in why some species are capable of establishing and some are not. It’s a difficult question. Something can fail to establish 20 times and the 21st time it will establish. There can be small releases and something becomes established, or thousands can be released and not establish.

“Is it habitat? Is it parental care? The air? What makes a better invader? What is the role of the invaded systems themselves?”

The Asian Swamp Eel is an example of an accidental release Hill is studying. The eels are popular in ornamental aquaculture for their odd appearance and in the food fish trade, where they are farmed for Asian markets. Watson said ornamental fish farmers were concerned the eels, which have a reputation as a “gluttonous, voracious predator, eating everything in their path,” would get into ponds and eat the fish stock.

But research showed the eels prefer insects, small crustaceans, worms and tadpoles — not ornamental fish, making them no threat to aquaculture. But a population of the eels has taken up residence next to Everglades National Park, and their effect on the ecosystem is not yet known.

Craig Watson
Director, Tropical Aquaculture Laboratory
(813) 671-5230