A prehistoric water species, the sea lamprey, will be making its way to Vermont's freshwater lake this week. Also known as the vampire fish, the eel-like species are a nuisance, according to the Vermont Fish & Wildlife, yet rarely attack humans.

At about two feet long with a round mouth filled with jagged teeth, the sea lamprey survives by sucking the blood and fluids of other fish. State officials say that the largest, threatening population is in Lake Champlain. The Great Lakes Fishery Commission informs that although sea lampreys do not kill their hosts when they are in the Atlantic ocean, they are responsible for killing up to 40 pounds of fish in the Great lakes every year.

Lampreys are a fish species that lack scales, fins and gill covers. Similar to sharks, their skeletal structure is made of cartilage. The fish have a row of seven pairs of gill openings behind their eyes and mouth.

Their round mouth acts like a suction mechanism, with horny teeth and a tongue with small, sharp plates. They may attack their prey for hours, days, and even weeks.

Sea lampreys have been invading the Great Lakes since the 1830s through the Welland Canal, starting with Lake Ontario and Lake Erie. Within ten years, the lampreys have invaded all five lakes, attacking commercial fish such as perch, trout, and whitefish, causing a collapse to trout populations within 100 years.

The Aquatic Vampire

Human attacks are rare, but there had been a few recorded instances, such as Christopher Swain's story, a long-distance swimmer. On an episode of River Monsters, he brings the host Jeremy to the place where he was attacked by an 'aquatic vampire.'

Christopher was in the middle of a 129-mile swim in a lake. The first sensation he felt was similar to 'when your mobile phone [is] in your pocket and it vibrates.' Reaching down, he realized that he didn't just brush up against something, but a three or four-foot snake-like creature was attached to his leg.

When he was finally able to remove the slippery creature off his leg, it immediately attached back on. Christopher removed the sea lamprey a second time and flung it in the air as he finished his swim for the day. The swimmer shared that it is an experience that really got to him - more than swimming through lighting storms, being run over by boats, and swimming through nuclear waste.

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Regulating Their Numbers

In the Connecticut River, state officials have documented a less threatening sea lamprey species that do not threaten other fish and have become an essential part of the local ecosystems.

Lael Will from the Vermont Fish & Wildlife said, 'If you happen to see a spawning sea lamprey or a lamprey carcass, don't be alarmed. The fish provide a number of important ecological benefits and are considered a Species of Greatest Conservation Need in both Vermont and New Hampshire.'

Adult lampreys die shortly after spawning. Their carcass then becomes a source of food for other marine species and local birds.

They also breed in the lake waters where larval lampreys stay for about five years, filtering small particles in the water for food. After maturing, they swim downstream towards the Atlantic Ocean where they spawn on fish and once in a while return to the lakes if they can get past the barriers.

Today, the Great Lakes Fishery Commission controls the sea lampreys in the Great Lakes alongside the U.S. Fish and Wildlife Service and Fisheries and Oceans Canada. They have built several dams around the lakes to regulate the number of lampreys entering the freshwater lakes.

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