Species and Origin: The common carp is a large omnivorous fish. They have large scales, a long dorsal fin base, and two pairs of long barbels (whiskers) in its upper jaw. Native to Europe and Asia, it was intentionally introduced into Midwest waters as a game fish in the 1880s.
(Be aware of a native look-a-like: the native fish bigmouth buffalo looks like a carp without barbells)

Impacts:

• Common carp are one of the most damaging aquatic invasive species due to its wide distribution and severe impacts in shallow lakes and wetlands
• Their feeding disrupts shallowly rooted plants muddying the water
• They release phosphorus that increases algae abundance
• Carp induced declines in water quality causes declines of aquatic plants needed by waterfowl and fish

Status: They are established in 48 states. They are distributed in hundreds of waters in the southern two-thirds, and a few waters in the northern third of Minnesota. See US map.

Means of spread: The incidental inclusion and later release of live bait spreads common carp.

Common names: Curly cabbage, crisp pondweed.

Location: Grows from the shore to depths of up to 15 feet.

Description: Leaves are somewhat stiff and crinkled, approximately 1/2-inch wide and 2 to 3 inches long; leaves are arranged alternately around the stem, and become more dense toward the end of branches; produces winter buds can be confused withclaspingleaf pondweed.

Hints to identify: Has small "teeth" visible along edge of leaf; begins growing in early spring before most other pondweeds; dies back during midsummer; the flower stalks, when present, stick up above the water surface in June; appears reddish-brown in the water, but is actually green when pulled out of the water and examined closely. Easily confused with claspingleaf pondweed, which has leaves with no "teeth" around their edges.

Importance of plant: Provides some cover for fish; several waterfowl species feed on the seeds; diving ducks often eat the winter buds.

Eurasian watermilfoil was accidently introduced to North America from Europe. Spread westward into inland lakes primarily by boats and also by waterbirds, it reached Midwestern states between the 1950s and 1980s.

In nutrient-rich lakes it can form thick underwater stands of tangled stems and vast mats of vegetation at the water's surface. In shallow areas the plant can interfere with water recreation such as boating, fishing, and swimming. The plant's floating canopy can also crowd out important native water plants.

A key factor in the plant's success is its ability to reproduce through stem fragmentation and runners. A single segment of stem and leaves can take root and form a new colony. Fragments clinging to boats and trailers can spread the plant from lake to lake. The mechanical clearing of aquatic plants for beaches, docks, and landings creates thousands of new stem fragments. Removing native vegetation creates perfect habitat for invading Eurasian watermilfoil.

Species: Large, olive colored snails.

Origin: Chinese mystery snail (CMS) is native to Asia. It was brought to California in 1892 as a food source, and found in Massachusetts in 1915 — likely an aquarium release. The historic range of the banded mystery snail (BMS) is the southeastern U.S., primarily in the Mississippi River system up to Illinois. It is a popular aquarium snail that’s been released in Minnesota.

Impacts: Both snails can form dense aggregations. In Asia, the CMS can transmit human intestinal flukes, however, cases have not been documented in the United States. It also is a carrier of trematode parasites found in native mussels. BMS can cause mortality of largemouth bass embryos when they invade nests.

Status: CMS are present in over 80 waters and BMS occurs in about 50 waters in Minnesota.

Regulatory classification (agency): Chinese, Japanese, and other mystery snails (species in the genus Bellamya / Cipangopaludina) are regulated invasive species (DNR). The banded is an unlisted nonnative species. All are illegal to introduce into state waters.

Means of spread: Most likely introduced via dumping of aquariums and by transfer from one water body to another.

Keys to identification: Chinese mystery snail has small shallow depressions above the shell opening and rows of fine, short stiff hairs parallel to the whorl of the shell (may wear off with age and abrasion).

Banded mystery snail has red bands that are parallel to the whorl of the shell.