LEWISTON – A voracious predator illegally introduced into Maine waters years ago continues its spread, this time invading pristine No Name Pond.

State fisheries biologist Brian Lewis confirmed the presence of northern pike in No Name Pond on Friday. Lewis announced the discovery Tuesday in the weekly fishing report published by the state Department of Inland Fisheries and Wildlife.

Lewis said “what appeared to be two different age classes of pike” were observed. That often means the fish have been in the waters for an extended time, long enough to begin reproducing.

Lewis, though, noted that his unfamiliarity with the nature of No Name’s outlet made it unclear how the pike made it to the pond. It’s possible, he suggested, that they might have migrated to the pond via brooks and streams feeding Sabattus River. Pike have long been established in Sabattus Pond.

Or, Lewis wrote, the predator might have been illegally introduced to the pond by anglers who prefer the pike over native game fish. That’s how pike gained a foothold in Maine waters originally.

“They’re everywhere now,” said Mike Harnden, who works at Stone’s Bait and Tackle in Lewiston. He said northern pike are also flourishing in the Androscoggin River, where they’d be more likely to menace bass than Maine’s traditional game fish: salmon and brook trout.

At No Name, brook trout have been stocked by the state. The pond also has been known to produce landlocked salmon, the result of previous stockings.

“Pike are very aggressive eaters,” Harnden noted, and pose a threat to species such as No Name’s trout.

Harnden said No Name anglers could help curb pike populations by killing any northerns that they catch.

State fisheries experts bemoan the extent of northern pike in Maine, largely because they’re such a threat to native species. Pike, which often grow to 20 and 30 pounds, are at the top of the marine food chain.

They’re also prolific. The invader was found last year in a stream in Fayette that flows into the Sandy River. If pike migrate to the Sandy, they could eventually take up residence in the Kennebec River below Madison. And to the west, the only thing keeping them from reaching the Rangeley Lakes area from the Sandy is Smalls Falls.

Pike also were found last year in Sebago Lake, the state’s second-largest, and home to native landlocked salmon, brook trout and lake trout. That has fisheries experts worried.

“When (pike) got into Long Pond in the Belgrade Lakes, they decimated the salmon fishery,” said Mark Latti, a spokesman for the IF&W.

Bobby Van-Riper, another IF&W biologist, called illegal stocking of pike “insidious.”

Last year, discussing the pike threat to the Sandy River, Van-Riper said, “These are not sportsmen and women; they couldn’t care less about the fishing of others.”