For pet owners, it is the pit bull of fish -- a species known to gobble goldfish whole, jump out of its tank and even shatter an aquarium with its thrashing.

So when Maryland officials proposed a ban on possessing the snakehead, the fish's fans were, quite predictably, upset.

It's as if, they said, wild tabbies were killing Maryland's songbirds, and the state solved the problem by banning all orange cats -- period.

Or, continues Ruth Hanessian, president of the Maryland Association of Pet Industries, as if poodles became a nuisance, then "all of the sudden they're banning all dogs, and you had to turn in your pet. . . . How would you feel?"

As Maryland officials mull emptying the state entirely of 29 breeds of snakehead fish -- not just prohibiting the importing and selling of the region's piscatorial Public Enemy No. 1, but also the actual possession -- a couple of dozen lobbyists, pet owners and pet store owners protested last night in Annapolis.

Jim Karanikas, owner of Tropical Fish World in Gaithersburg, said he attended the hearing on behalf of his customers with snakeheads.

"One was going to come today, but he was afraid you were going to take it from him," he said during the hearing.

Federal law prohibits importing snakeheads into the country, carrying them across state lines and dumping them in local waters. Maryland is developing regulations on the fish, said Gina M. Hunt, director of policy and regulatory services for the state Department of Natural Resources Fishery Services. Virginia has banned possession of snakeheads. The District has no laws on snakehead possession, but it is governed by federal restrictions.

Protesters and speakers in Annapolis yesterday were asking that pet owners who have snakeheads "be grandfathered in, and that's one thing we will be looking at," said department spokeswoman Heather Lynch.

Tropical breeds of the snakehead that are most often sold to fish lovers typically could not survive the region's cold winter, but the northern snakehead has been found in two Maryland ponds and the Potomac River and its tributaries.

State officials believe the fish are finding their way into waterways because pet owners are tiring of the voracious predators and dumping them out. Once in the water, the snakehead could disrupt the ecosystem by eating other fish, officials fear.

Ponds in Wheaton and Crofton have been drained in hopes of eliminating the fish. But with the discovery of nine snakeheads in the Potomac's open waters in the past two months, officials acknowledge that there's no stopping the Asian import.

In many ways, what frightens naturalists about the fish is what delights some pet owners.

"They eat other fish -- that's the attraction," said Birgit Sexton, 55, who has worked for the past 14 years at Glen Burnie's House of Tropicals.

Snakeheads eat their prey whole, unlike piranhas, which nibble and pick at their meat.

"They're like stomachs with fins," said Chris Phillips, 19, an Anne Arundel Community College student who used to own a cobra snakehead.

At one point, the fish leaped from its tank, and Phillips came into the room and found it lying on the floor.

"It had dust all over it and was about to die, but I put it back in, and it came back to life," Phillips said, still marveling. Not long after that, though, the fish leaped out again, and Phillips couldn't save it. "If your tank's not covered completely, it'll find a way out," he said.

Right before the federal law banned the sale of snakeheads two years ago, the fish store where Sexton and Phillips work received its final shipment of a couple of dozen baby snakeheads. Generally, the snakeheads sold for $6 each -- and they "didn't sell any faster than any other aggressive fish," Phillips said. "But as soon as they were [about to be] outlawed, we couldn't keep them in stock."

The snakehead price doubled, and even then, "they went quick."

It's the perception -- and even hope -- of angry attacks that lure some fish owners to the snakeheads and other "aggressive" fish, like piranhas and arapaimas, a Brazilian fish, pet shop workers said.

Like the snakehead, the arapaimas eat their fish whole, and when Phillips dropped a couple of coin-size goldfish into the tank, the long, tubular fish zoomed straight for the goldfish, effortlessly opening their mouths and gobbling. The South Americans' heads, normally as flat as an envelope, bulged wide until suddenly, the goldfish were gone and their gullets shrank flat again.

It was like watching the Discovery Channel. Live.

Some snakeheads, said Kevin Farrell, owner of Critters pet store in Bowie, "are as big around as a man's leg. . . . They're scary as hell and can eat you out of house and home."

Yet that's part of the attraction.

"They break tanks when they get big. They swim with such force that when they hit the side of the tank, it shatters," Phillips said.