AIS Library

Background Information

Wisconsin’s Department of Natural Resources (DNR) defines an invasive species as a “nonindigenous species whose introduction causes economic or environmental harm or harm to human health” (WI Statute Section 23.22 (1) (c). These nonindigenous or non-native species can succeed in new habitats because they can quickly adapt to new environments and their native predators and competitors are absent. Invasive species can significantly alter ecosystem functions, economic value, ecological relationships, recreation, and human health.


AIS DNR Logo. Why Should We Care About Invasive Species?

The website’s goal is to provide a modern tool for public education about aquatic invasive species around Wisconsin, especially larval and adult fish identification. Currently, the Great Lakes have been significantly impacted by Sea Lamprey, Tubenose or Round Gobies, Eurasian Ruffe, Zebra Mussel, Alewife, White Perch, Asian Clam, and Asian Carp (Grass, Bighead, Silver, Common, etc). Some methods to control aquatic invasive species in Lake Michigan are reducing human transportation of these species, evaluate restoration efforts towards fish and aquatic habitats, assistance from local communities, enhance outreach and education efforts, increase monitoring, respond to emerging threats, step-up enforcement, and continue to collaborate with other organizations (DNR & UW – Sea Grant).

Aquatic Invasive Species Library (AIS Logo). Adam Dziewa/Katie Vogel. 2018



AIS Library


This library consists of aquatic invasive species pictures and resources to assist interested parties in properly recognizing and reporting a discovery of one of these species. The AIS Library was created using multiple links from numerous sources that include the DNR, UW-Sea Grant, USGS, USFWS, and other agencies or universities.

*Please click on the photos in order to access more information on each species.*

Amur Honeysuckle  Asian Clam
Asian marshweed Aquatic-forget-me-not
Banded Mystery snail Bighead Carp
Black carp Bloody-Red Shrimp
Brazilian waterweed Brittle Naiad
Canada Thistle Carolina Fanwort
Cattail hybrid Chinese mysterysnail
Common Buckthorn Common Carp
Common Teasel Curly-leaf pondweed
Cut-leaved teasel Dame’s rocket
Didymo or Rock Snot Duck Lettuce
Eurasian water-milfoil European frog-bit
Valvata piscinalis Faucet snail
Floating Marsh Pennywort Floating Water hyacinth
Flowering rush Giant Reed
Giant Salvinia Goldfish
Grass Carp Hawaii Arrowhead
Hydrilla Japanese Honeysuckle
Java Waterdropwort or Vietnamese parsley Killer Algae
Malaysian Trumpet Snail Mudmat
Narrow-leaf Cattail Non-native Phragmites or Common reed
New Zealand Mudsnail Parrot feather
Poison Hemlock Purple loosestrife
Quagga Mussel Red Swamp Crayfish
Round Goby Ruffe
Rusty Crayfish Sea Lamprey
Silver Carp Snakehead Family
Spiny naiad Spiny Water Flea
Starry stonewort Tubenose Goby
Water chestnut Water Lettuce
Water Spinach, Swamp Morning-Glory Yellow Floating Heart
Yellow Iris Zebra Mussel


Aquatic Invasive Species Visuals


Amur Honeysuckle - (Lonicera maackii) (Regulated/Prohibited & Restricted)

Amur Honeysuckle (Lonicera maackii).
DNR: Regulated/Prohibited & Restricted.
Brooke M. Hushagen & DNR.

Asian Clam (Corbicula fluminea) (Regulated/Prohibited)

Asian Clam (Corbicula fluminea).
DNR: Regulated/Prohibited.
UW – Sea Grant & USGS.

Asian marshweed (Limnophila sessiliflora) (Regulated/Prohibited)

Asian marshweed (Limnophila sessiliflora).
DNR: Regulated/Prohibited.
Vic Rammay & DNR.

Aquatic-forget-me-not – (Myosotis scorpioides) (Regulated/Restricted)

Aquatic-forget-me-not (Myosotis scorpioides).
DNR: Regulated/Restricted.
Christian Fischer & DNR.

Banded Mystery snail - Viviparus georgianus (Regulated/Restricted)

Banded Mystery snail (Viviparus georgianus).
DNR: Regulated/Restricted.
Amy Benson, USGS, DNR.

Bighead Carp Hypophthalmichthys nobilis (Regulated/Prohibited)

Bighead Carp (Hypophthalmichthys nobilis).
DNR: Regulated/Prohibited.
Amy Benson, USGS, DNR.

Black carp Mylopharyngodon piceus (Regulated/Prohibited)

Black carp (Mylopharyngodon piceus).
DNR: Regulated/Prohibited.
Leo Nico, USGS, DNR.

Bloody-Red Shrimp (Hemimysis anomala)  (Regulated/Prohibited)

Bloody-Red Shrimp (Hemimysis anomala).
DNR: Regulated/Prohibited.
NOAA Great Lakes Environmental Research Lab, UW – Sea Grant, DNR.

Brazilian waterweed – Egeria densa (Regulated/Prohibited)

Brazilian waterweed (Egeria densa).
DNR: Regulated/Prohibited.

Brittle Naiad – Najas minor (Regulated/Prohibited)

Brittle Naiad (Najas minor).
DNR: Regulated/Prohibited.

Canada Thistle - (Cirsium arvense) (Regulated/Restricted)

Canada Thistle (Cirsium arvense).
DNR: Regulated/Restricted.
Stephen Solheim & DNR.

Carolina Fanwort (Cabomba caroliniana) (Regulated/Prohibited)

Carolina Fanwort (Cabomba caroliniana).
DNR: Regulated/Prohibited.
DNR & Leslie Mehrhoff.

Cattail hybrid (Typha x glauca) (Regulated/Restricted)

Cattail hybrid (Typha x glauca).
DNR: Regulated/Restricted.
Elizabeth J. Czarapata, DNR.

Chinese mysterysnail Cipangopaludina chinensis (Regulated/Restricted)

Chinese mysterysnail (Cipangopaludina chinensis).
DNR: Regulated/Restricted.
Amy Benson, USGS, DNR.

Common Buckthorn - Rhamnus cathartica (Regulated/Restricted)

Common Buckthorn (Rhamnus cathartica).
DNR: Regulated/Restricted.
Elizabeth J. Czarapata, DNR.

Common Carp Cyprinus carpio (Regulated/Restricted)

Common Carp (Cyprinus carpio).
DNR: Regulated/Restricted.
Dezidor, USGS, DNR.

Common Teasel - Dipsacus fullonum (Regulated/Restricted)

Common Teasel (Dipsacus fullonum).
DNR: Regulated/Restricted.
Elizabeth J. Czarapata, DNR.

Curly-leaf pondweed (Potamogeton crispus)  (Regulated/Restricted)

Curly-leaf pondweed (Potamogeton crispus).
DNR: Regulated/Restricted. DNR

Cut-leaved teasel (Dipsacus laciniatus) - (Regulated/Restricted)

Cut-leaved teasel (Dipsacus laciniatus). DNR: Regulated/Restricted). DNR.

Dame's rocket (Hesperis matronalis) (Regulated/Restricted)

Dame’s rocket (Hesperis matronalis). DNR: Regulated/Restricted.
Nisa Karimi & DNR.

Didymo or Rock Snot Didymosphenia geminata (Regulated/Prohibited)

Didymo or Rock Snot (Didymosphenia geminata). DNR: Regulated/Prohibited.
T. Thorney, USDA, DNR.

Duck Lettuce (Ottelia alismoides) (Regulated/Prohibited)

Duck Lettuce (Ottelia alismoides).
DNR: Regulated/Prohibited. DNR & J. Garg.

Eurasian water-milfoil (Myriophyllum spicatum) (Regulated/Restricted)

Eurasian water-milfoil (Myriophyllum spicatum).
DNR: Regulated/Restricted.
DNR/Elizabeth J. Czarapata.

European frog-bit (Hydrocharis morsus-ranae) (Regulated/Prohibited)

European frog-bit (Hydrocharis morsus-ranae). DNR: Regulated/Prohibited.
Erich Haber/DNR.


European stream (Valvata  piscinalis). DNRRegulated/Restricted.
Amy Benson, USGS, DNR.


Faucet snail (Bithynia tentaculate). DNR: Regulated/Prohibited.
Amy Benson, USGS, DNR.


Floating Marsh Pennywort (Hydrocotyle ranunculoides).  DNR: Regulated/Prohibited.


Floating Water hyacinth (Eichhornia crassipes). DNR: Regulated/Prohibited. DNR.


Flowering rush (Butomus umbellatus). DNR: Regulated/Restricted. DNR.


Giant Reed (Arundo donax). DNR: Regulated/Prohibited. David Moorhead & DNR.


Giant Salvinia (Salvinia molesta). DNR: Regulated/Prohibited.
Forest and Kim Starr/DNR.


Goldfish (Carassius auratus). DNR: Regulated/Restricted.
M.E. Brown, USGS, DNR.


Grass Carp (Ctenopharyngodon idella). DNR: Regulated/Prohibited. USFWS, USGS, DNR.


Hawaii Arrowhead (Sagittaria sagittifolia). DNR: Regulated/Prohibited.
Christian Fischer/DNR.


Hydrilla (Hydrilla verticillata). DNR: Regulated/Prohibited. Kerry Dressler/DNR.


Japanese honeysuckle (Lonicera japonica). DNR: Regulated/Prohibited. Nisa Karimi & DNR.

Java Waterdropwort or Vietnamese parsley (Oenanthe javanica) (Regulated/Prohibited) KENPAI/DNR

Java Waterdropwort or Vietnamese parsley
(Oenanthe javanica). DNR: Regulated/Prohibited. KENPAI & DNR.

Killer Algae - Caulerpa taxifolia (Regulated/Prohibited) Rachel Woodfield - Merkel & Associates, Inc. , USDA, DNR

Killer Algae (Caulerpa taxifolia).
DNR: Regulated/Prohibited. Rachel Woodfield – Merkel & Associates, Inc., USDA, DNR.

Malaysian Trumpet Snail - Melanoides tuberculatus (Regulated/Prohibited) Bill Frank (FL), USGS, DNR

Malaysian Trumpet Snail (Melanoides tuberculatus). DNR: Regulated/Prohibited. Bill Frank (FL), USGS, DNR.

 Mudmat (Glossostigma cleistanthum) (Regulated/Prohibited) Leslie Mehrhoff/DNR

Mudmat (Glossostigma cleistanthum).
DNR: Regulated/Prohibited. Leslie Mehrhoff/DNR.

Narrow-leaf Cattail – Typha angustifolia (Regulated/Restricted) Elizabeth J. Czarapata, DNR

Narrow-leaf Cattail (Typha angustifolia).
DNR: Regulated/Restricted. Elizabeth J. Czarapata, DNR.

Non-native Phragmites or Common reed (Phragmites australis) (Regulated/Prohibited & Restricted) Elizabeth J. Czarapata, DNR

Non-native Phragmites or Common reed (Phragmites australis). DNR: Regulated/Prohibited & Restricted.  Elizabeth J. Czarapata, DNR.

New Zealand Mudsnail - Potamopyrgus antipodarum (Regulated/Prohibited) DNR

New Zealand Mudsnail (Potamopyrgus antipodarum). 
DNR: Regulated/Prohibited. DNR.

Parrot feather (Myriophyllum aquaticum) (Regulated/Prohibited) DNR

Parrotfeather (Myriophyllum aquaticum).
DNR: Regulated/Prohibited. DNR.

Poison Hemlock - (Conium maculatum) (Regulated/Prohibited & Restricted) DNR

Poison Hemlock (Conium maculatum).
DNR: Regulated/Prohibited & Restricted. DNR.


Purple loosestrife (Lythrum salicaria). DNR: Regulated/Restricted.
Elizabeth J. Czarapata, DNR.


Quagga Mussel (Dreissena bugensis). DNR: Regulated/Prohibited. Myriah Richerson, USGS, DNR.


Red Swamp Crayfish (Procambarus clarkii). DNR: Regulated/Prohibited.


Round Goby (Neogobius melanostomus). DNR: Regulated/Restricted. 
Center for Great Lakes and Aquatic Sciences Archive, University of Michigan, USGS, DNR.


Ruffe (Gymnocephalus cernua). DNR: Regulated/Restricted.
Steffen Zienert, USGS, DNR.


Rusty Crayfish (Orconectes rusticus). DNR: Regulated/Restricted.
Tennessee Wildlife Resources Agency, USGS, DNR.


Sea Lamprey (Petromyzon marinus). DNR: Regulated/Restricted.
Great Lakes Fishery Commission, USGS, DNR.


Silver Carp (Hypophthalmichthys molitrix). DNR: Regulated/Prohibited. Department of Fisheries and Allied Aquacultures, Auburn University, Alabama, USA. USGS. DNR.


Snakehead Family (Channidae).DNR: Regulated/Prohibited. P.R. Sweet, USGS, DNR.


Spiny naiad (Najas marina). DNR: Regulated/Restricted. 
Paul Skawinski/DNR.


Spiny Water Flea (Bythotrephes longimanus). DNR: Regulated/Prohibited.
J. Liebig, NOAA GLERL, 2001, USGS, DNR.


Starry stonewort (Nitellopsis obtusa). DNR: Regulated/Prohibited. Paul Skawinski, DNR.


Tubenose Goby (Proterorhinus marmoratus). DNR: Regulated/Restricted. UW – Sea Grant, DNR.


Water chestnut (Trapa natans). DNR: Regulated/Prohibited. DNR.


Water Lettuce (Pistia stratiotes). DNR: Regulated/Prohibited. Leslie Mehrhoff/DNR.


Water Spinach, Swamp Morning-Glory (Ipomoea aquatica). DNR: Regulated/Prohibited.
Eric Guinther/DNR.


Yellow Floating Heart (Nymphoides peltata).   DNR: Regulated/Prohibited.
Karel Jakubec/DNR.


Yellow Iris (Iris pseudacorus).  DNR: Regulated/Restricted. DNR.


Zebra Mussel (Dreissena polymorpha).  DNR: Regulated/Restricted. Amy Benson, USGS, DNR.