From Its Native Asia To Florida -
The Tale Of The Cobra Snakehead (page 2 of 3)

Here are some good extracts of that report entitled

NEW EXOTIC FISH NOW PRESENT IN FLORIDA'S FRESHWATER SYSTEM:
WEST PALM BEACH--An Asian fish commonly known as a snakehead is the most recent addition to Florida's list of reproducing exotic fishes, scientists reported this week. "However, it's far too early to know or even speculate on what effects the presence of this snakehead will have," according to Paul Shafland, director of the Florida Fish and Wildlife Conservation's (FWC) Non-Native Fish Lab in Boca Raton. 

There are now 31 documented exotic fish species reproducing in Florida's fresh waters. Some of the better-known exotic residents include the walking catfish, Asian swamp eel, and oscar. The snakehead is an air-breathing fish similar in appearance and behavior to the native bowfin (or mudfish). Shafland said angler Bob Newland of Sunrise caught the first documented snakehead on October 5, 2000 while fishing a residential pond in Tamarac, Broward County. The angler initially thought it was a bowfin until noticing the ocellus, a distinctive dark spot rimmed in brilliant orange near the base of the tail fin. The fish measured 26 inches long and weighed four pounds.

The fish was tentatively identified at the lab as a snakehead by Shafland, who then sampled the catch site the next day, assisted by fisheries technician Murray Stanford. The researchers visually observed two large snakeheads measuring from 20 to 24 inches and collected a smaller specimen around 12 inches long using electroshocking equipment. More than 100 snakeheads from 6 to 28.5 inches long and from one ounce to six pounds have been collected so far. FWC is sharing information with other agencies studying exotic fishes, including scientists from the United States Geological Survey. Specimens of this fish have been given to Jim Williams and Leo Nico of the USGS in Gainesville for positive identification. ?

"There is relatively little information on the life histories and ecology of most fish species from tropical Asia," Shafland said. " As a result, useful information about how these fishes may interact with native species is sparse and some of it, especially in older sources, is suspect. Snakeheads have been described as being extremely aggressive and voracious, but based on our personal observations the species collected in Florida appears to be one of the less aggressive species of snakeheads.

We hope the public doesn't over react as was the case with the media inspired hysteria regarding the appearance of the walking catfish back in the 1960s and even the swamp eel a few years ago," he said. "The presence of this species immediately places it into the unwelcome and undesirable category, but more importantly it clearly demonstrates that illegal introductions of exotic fishes continue in Florida. "In fact, this is the sixth exotic fish that has been documented reproducing in Florida waters since 1992." Shafland said.

"Obviously we need to do more to educate the public about the serious ecological consequences that the illegal release of exotic species represent." Shafland pointed out that once a fish species is reproducing in the open water systems of south Florida, it is impossible to eradicate them. Preventing the illegal introduction of exotics in the first place is really the only viable tactic along with educating anglers, aquarists, and others about the illegality of dumping and/or transferring exotic fish from one water body to another. Shafland praised Newland for taking the time and effort to report catching what appeared to be a rather strange looking bowfin.

The Boca Raton scientist stated that the cooperation and assistance of knowledgeable anglers in identifying exotics is invaluable. "Our agency just doesn't have the staff and the resources to monitor every square foot of fresh water contained in Florida's numerous lakes, streams, rivers, canals, and impoundments," he said. "Anglers are often the first to detect the presence of an exotic fish, and we often depend on their reports." Since the first snakehead was caught in October, FWC scientists at the Boca Lab have initiated a comprehensive effort to determine their distribution, relative abundance, temperature tolerance, and associations with native fish. Food habits, habitat preferences, and reproduction will also be closely studied.

"Unfortunately, there are no quick fixes once an exotic fish begins reproducing and these studies will require several years to complete," Shafland said. "We have already completed some preliminary temperature tolerance studies that indicate this snakehead cannot live in water temperatures below 50 degrees. "This is good news and bad news," he said. "The good news is that snakeheads will be largely limited to the southern half of Florida due to lower winter temperatures farther north. The bad news is that much of southern Florida likely provides suitable habitat for this undesirable fish to establish a permanent home in."

"Our initial stomach content evaluations showed that more than 50 percent of their food consisted of crayfish," said Kelly Gestring, an FWC research scientist at Boca Raton.  "Now that could in the long run have an effect on other species that feed on crayfish, but it's far too early to know what, if any effects this new exotic fish will ultimately have."

Shafland explained that exotics can sometimes adversely affect native species and habitats by changing the energy flow in the ecosystem, introducing parasites and diseases, genetic pollution of closely related species, and by competing with native species for food, shelter, and space. At the very least, even an otherwise innocuous exotic takes up space and energy that might someday be used more beneficially by a native species.

When forced to speculate on what effects the snakehead might have on native fishes, Shafland said that, "If there are any effects, these would most likely involve the bowfin (mudfish) since snakehead and bowfin share more than just general appearances. Both of these species are also predators that seem to have similar habitat and food preferences, and both can utilize air to survive in waters with little to no oxygen." Some of the literature on the snakeheads suggests this fish can reach lengths of four feet, although Shafland is skeptical.

There is no question, however, that the snakehead is highly valued throughout Asia for its food value and taste. "I have eaten a few snakeheads since we began our research into this species, and can attest to their excellent taste," Shafland said. "Their popularity as food within the Asian cultures in south Florida may even explain the presence of the snakehead in Florida waters." Although not the same species reproducing in Florida waters, FWC Wildlife Inspectors Lts. John West and Pat Reynolds, Division of Law Enforcement, found another species of live snakehead for sale in two oriental food markets in late February. Some customers apparently believe that in addition to tasting good, snakeheads have a medicinal benefit.

Chung Hing Oriental Market, NW 167th St., Miami, and P. K. Oriental Market, Pines Blvd., Pembroke Pines were both charged with possession of a prohibited freshwater fish. All species of snakeheads are illegal to possess live in the state of Florida. Possession of live snakeheads is a second degree misdemeanor punishable by up to a $500 fine and/or 60 days in jail.

West said six live snakeheads were seized at the Pembroke Pines market and eight at the Miami market. The fish all measured approximately 12 inches long. Florida law also makes it a crime for anyone to release any exotic fish into state waters.