# Exotic snail takes hold



## Hamilton Reef (Jan 20, 2000)

Exotic snail takes hold

EXOTIC SPECIES: A tiny snail from New Zealand that reproduces by cloning itself could spread to inland waters, expert says.

Five new exotic aquatic species have been discovered in Lake Superior -- including a tiny mudsnail from New Zealand that clones itself and is already wreaking havoc in some Rocky Mountain trout streams.

The five new species also include an amphipod, or freshwater "side swimmer" shrimp, and three new fingernail clams.	

The snail has no natural enemies in North America. They reproduce without mating by producing fully formed clones of themselves. One snail can produce hundreds of thousands of clones of itself in a year.	(more)

Duluth News Tribune | 05/16/2003 | Exotic snail takes hold 
http://www.duluthsuperior.com/mld/duluthtribune/5874857.htm


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## Hamilton Reef (Jan 20, 2000)

Bad news, but we knew it was just a matter of time.

Hardy invader takes up residence

LAKE SUPERIOR:A tiny exotic from New Zealand -- highly adaptable, able to clone itself and without a natural enemy -- has begun to colonize in the Twin Ports harbor.

Tue, May. 02, 2006 BY JOHN MYERS NEWS TRIBUNE STAFF WRITER
(218) 723-5344 or by e-mail at [email protected]

A tiny mudsnail from New Zealand that clones itself and already is wreaking havoc in Rocky Mountain trout streams has colonized the Duluth-Superior harbor.

More than 100 New Zealand mudsnails were collected in the harbor by a private research team contracted by the Environmental Protection Agency's Mid-Continent Ecology lab in Duluth.

It's the first time the snail has been found on the U.S. side of Lake Superior, but the finding wasn't unexpected.

Scientists found the snails last fall and timed Monday's announcement to coincide with upcoming fishing seasons, hoping to remind anglers not to spread the exotic species to inland lakes and rivers.

The tiny mudsnails came to the United States in 1987, infesting the Snake River in Idaho, most likely imported with New Zealand trout. They have spread rapidly across the mountain West, apparently by trout anglers.

The first Great Lakes spotting of the snails occurred in Lake Ontario in 1991, and it's believed they are transported around the lakes in the ballast of ships.

The News Tribune reported in 2003 that mudsnails were found in Thunder Bay. Scientists expected the snails to colonize the St. Louis River estuary in the Twin Ports because of its warmer, more fertile waters and because the port sees so many Great Lakes ships.

"I kind of expected to find them," Igor Grigorovich, the scientist who found the species both in Thunder Bay and Duluth, said in a prepared statement. "The St. Louis River estuary is a more suitable habitat for this snail species than Lake Superior because it's not as cold."

Grigorovich said the specimens found in the Twin Ports look different than the ones he found in Thunder Bay. The Twin Ports residents have thicker shells while the Thunder Bay snails were semi-transparent, probably because of lower calcium levels in the water there.

The snail -- about the size of a peppercorn -- has no natural enemies in North America. They reproduce without mating by producing fully formed clones of themselves. One snail can produce hundreds of thousands of clones of itself in a year.

Like other invading species, the full impact of mudsnails may not be known for years. The snails have adapted so well in western U.S. rivers that they virtually have wiped out native snails. In some rivers, such as the Madison near Yellowstone National Park, mudsnails have colonized in numbers as high as 300,000 per square meter.

That's like having a half-million of the snails in your bathtub, said Doug Jensen, aquatic invasive species program coordinator for Minnesota Sea Grant in Duluth.

Limited research in western streams shows the exotic may also be displacing native species like caddis flies and mayflies that form the backbone of a trout stream's ecosystem.

"They have adapted so well in Western rivers that they have pushed out almost all of the native insects, snails and other invertebrates that are important food for fish," Jensen said.

If swallowed by fish, the mudsnails can close trapdoors in their shells that prevent fish from digesting them -- so the fish expend energy eating the snails, but get no nutritional value from them.

The trapdoor also allows the snails to survive out of the water for up to a week, Richards said, and makes other disinfection efforts, such as bleach, ineffective.

Unlike other foreign species that have colonized in Lake Superior -- such as the zebra mussel, goby and ruffe -- the mudsnail appears to favor colder water.

A parasitic fluke controls mudsnail numbers in its native New Zealand, but the fluke apparently didn't accompany the mudsnails to North America. Researchers are considering importing the fluke, but it may take years of testing to determine if the flukes might cause their own problems here.

So far, only water warmer than 113 degrees and freezing them for extended periods have killed mudsnails in large numbers.


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## Hamilton Reef (Jan 20, 2000)

Invasive Snail Found in Minn. Harbor 

The snail, called the New Zealand mudsnail, is only about as large as a peppercorn when fully grown. But one snail and its offspring can generate hundreds of thousands of clones each year.

The mudsnails were first found in Idaho's Snake River in 1987, and have affected Rocky Mountain trout streams. They were first spotted in the Great Lakes in Lake Ontario in 1991.

http://hosted.ap.org/dynamic/storie...NAIL?SITE=WIMIL&SECTION=HOME&TEMPLATE=DEFAULT


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## Hamilton Reef (Jan 20, 2000)

Every new alien species poses new risk to Lakes

Before 1988 only a handful of Michigan residents likely knew  or cared  what a zebra mussel was. What would happen if a few were dumped into the Earth's freshwater seas, the Great Lakes, was anybody's guess.

Now, much to our regret, we know all too well what the zebra mussel is and what it can do when it reproduces unchecked. And unless we are incredibly lucky, everyone will soon know just what a New Zealand mudsnail is, too, and what it can do to our lakes.

All because the Great Lakes shipping industry, the U.S. Coast Guard, the Interior Department, the U.S. Senate and a host of other agencies haven't done the job that American citizens expect of them.

http://www.record-eagle.com/2006/may/05edit.htm


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## Hamilton Reef (Jan 20, 2000)

MUD SNAIL SLIMES INTO GREAT LAKES

http://www.glrc.org/transcript.php3?story_id=3051

Mike Simonson June 5, 2006

A foreign invasive species is spreading to new areas. It's a snail that could spread in huge numbers and compete with fish for food. The GLRC's Mike Simonson reports: 

The New Zealand Mudsnail has made its way to Lake Superior. It had already been identified in Lake Ontario. These snails become dense on a river or lake bottom. Minnesota Seagrant Aquatic Species expert Doug Jensen says it's like having half a million in the space of a bathtub. They can squeeze out bottom dwelling organisms that fish eat. Jensen says native fish eat New Zealand Mudsnails, but the fish don't digest them: 

"They can pass through the guts of fish and potentially waterfowl and then survive that situation and then breed in a new location, where ever they're deposited. They reproduce asexually. They produce clones of themselves; they don't need a male to establish a new colony." 

The snails are the latest on a long list of invasive species that have likely been carried in by foreign ships. 

For the GLRC, Im Mike Simonson


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## Hamilton Reef (Jan 20, 2000)

New Zealand Mud Snails Invade Lake Erie!

The snail was found at several sites in three locations in Lake Erie (near Buffalo, NY, Erie, PA, and Put-in-Bay, OH). "Because the snail was found in such diverse locations, it is likely that it has been established in Lake Erie for some time," says Ed Levri, a biologist at Penn State - Altoona. "It has probably avoided detection due to its small size and the fact that it appears to be relegated to relatively deep water."

The New Zealand mud snail is an invasive species native to New Zealand. Populations of the species have been established in North America for at least 15 years. One large population exists in rivers of the western United States where they appear to be responsible for substantial ecological damage. A population can also be found in the Great Lakes, where, until now, have been found only in Lakes Ontario and Superior. 

http://www.iaglr.org/jglr/release/33/33_1_1-6.php


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## Hamilton Reef (Jan 20, 2000)

Invasion of the New Zealand mud snails
Species could change ecosystems in eastern North America, researchers say

They are only a few millimetres long, hard-shelled and humble. But the New Zealand mud snails have laid siege to four of the five Great Lakes and are threatening to invade rivers and streams, too.

A Penn State research team says these foreign-intruder species that have long been a problem in the western United States could have the ability to change ecosystems in the East.

"Invasive species in general often have substantial negative effects. ... My biggest concern is about them getting into the streams and rivers that are emptying into the Great Lakes - and they are there right now," Edward Levri, an associate professor of biology at Penn State's Altoona campus, said yesterday.

http://www.theglobeandmail.com/servlet/story/LAC.20080808.SNAILS08/TPStory/Environment


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## Zorba (Jan 24, 2007)

What do they do? What do you mean by substantial ecological damage? What danger are they to the great lakes?


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## rockbass (Dec 8, 2007)

I love erotic snails.......wait, what?


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