Invasive Species List/Aquatic Animals

This page contains information on aquatic animal species on the Invasive Species List. For more general information about the event, see Invasive Species.

Aquatic Animals

Alewife (Alosa pseudoharengus)

• Taxonomy: Kingdom-Animalia; Phylum-Chordata; Class-Actinopterygii; Order-Clupeiformes; Family-Clupeidae; Subfamily-Alosinae; Genus-Alosa; Species-A. pseudoharengus

Identification Tips:

• • Dark dorsal side; bluish-greenish; light sides with horizontal darker stripes
  • Black spot located behind eye

• Anatomy:

• Body:

• Eyes:

• Mouth:

• Misc/General:
  • 25-38 cm long

• Adaptive anatomy:

Introduction:

• How introduced: Where/when:

• How spread:

Life Cycle: Live to about 6-7 years, and reproduces at around two years. In less than a week, the young alewives hatch and begin feeding primarily on zooplankton. In the fall, the young alewives make their way back to the sea or into the deep waters of freshwater lakes or rivers.

• Egg: Spawn once a year from late April to early June. When anadromous, the fish can reach 12-15in. big, and females lay from 60,000-100,000 eggs. When landlocked the fish tend to grow only to about 6 inches, and the females will lay 10,000- 12,000 eggs.

• Reproduction: Anadromous (migrating up rivers from the sea to spawn) species, although there are some landlocked populations around the Great Lakes.

• General Reproduction:

• What makes it so good at reproducing?:

Ecology:

• Diet: When landlocked they will feed on the eggs and young of other fish, as well as their own. They also feed on the larger species of zooplankton. Adult alewives feed on zooplankton, aquatic insects, and small fish.

• Behavior:

• Niche:

• Trophic Level:

Native habitat:

• Characteristics of said habitat:

Where it’s a problem (“new” habitat):

• Characteristics of new habitat:

Preventative measures:

• Laws and effectiveness:

• Control measures and effectiveness: Increasing the predator base has been the most effective. Trout and salmon stockings have been successful in reducing the alewife population. These efforts have also created a multimillion dollar salmonid fishery.

• Damage (why it’s a problem):

Asian Carps

Asian carp is a term used to refer to introduced carp species native to Asia, the most significant of which include silver carp, bighead carp, grass carp, and black carp.

• Preventative measures: Virtually impossible to eradicate once infested. Electrical barriers, netting, electrofishing are some methods of control. As of 2013, the U.S. government has designated almost $80 million dollars towards Asian Carps.

Damage (why it’s a problem): Their voracious appetites can strip the food web of plankton and other organisms. Uproot vegetation and muddy water, competes with native species for food and living space. Regulations: Asian carp are listed as injurious wildlife under the Federal Lacey Act, which makes it illegal in the U.S. to import, export, or transport between States without a permit.

Silver Carp (Hypophthalmicthys molitrix)

• Taxonomy: Kingdom-Animalia; Phylum-Chordata; Class-Actinopterygii; Order-Cypriniformes; Family-Cyprinidae; Genus-Hypophthalmichthys; Species-H. molitrix
• Identification Tips: Low set eyes, downward slanting mouth. Keel extends all the way to throat, and has a smaller head than the Bighead Carp.
• Diet: Can eat 5-20% of their body weight a day. Silver carp are filter feeders, consuming algae, phytoplankton, and other microscopic organisms.
• Introduction:Introduced in 1973. Silver carp have been found in 17 states.

Bighead Carp (Hypophthalmichthys nobilis)

• Taxonomy: Kingdom-Animalia; Phylum-Chordata; Class-Actinopterygii; Order-Cypriniformes; Family-Cyprinidae; Genus-Hypophthalmichthys; Species-H. nobilis
• Identification Tips: Low set eyes, downward slanting mouth. Keel extends partway across body, and has dark splotches along back (dorsal) region.
• Diet: Filter feeder, can also eat 5-20% of their body weight a day. They lack a true stomach so they eat voraciously.
• Introduction: Introduced in 1972 for algae control in fisheries, first spotted in the wild in 1980s. Bighead carp have been found in the open waters of 23 states

Grass Carp (Ctenopharyngodon idella)

• Taxonomy: Kingdom-Animalia; Phylum-Chordata; Class-Actinopterygii; Order-Cypriniformes; Family-Cyprinidae; Subfamily-Leuciscinae; Genus-Ctenopharyngodon; Species-C. idella
• Introduction: First asian carp to be introduced to the US in 1963 by the USFWS. Used in controlling aquatic weeds and phytoplankton in aquaculture. First accidental release occurred in a lab, in Stuttgart, Arkansas. Grass carp alone has been recorded officially in 45 states.

Black Carp (Mylopharyngodon piceus)

• Taxonomy: Kingdom-Animalia; Phylum-Chordata; Class-Actinopterygii; Order-Cypriniformes; Family-Cyprinidae; Genus-Mylopharyngodon; Species-M. piceus
• Identification Tips: Darker color, human-molar like teeth, pointy face, with no scales on head.
• Diet: Mollusks, crustaceans, aquatic insects, and fish eggs. Their teeth allows them to crush shells. 4-year-old black carp is able to eat 3 to 4 pounds of mussels per day.
• Introduction: Imported in shipments of grass carp in 1970s unknowingly.

Asian Clam (Corbicula fluminea)

• Taxonomy: Kingdom-Animalia; Phylum-Mollusca; Class-Bivalvia; Subclass-Heterodonta; Order-Veneroida; Superfamily-Cyrenoidea; Family-Cyrenidae; Genus-Corbicula; Species-C. fluminea
• Identification Tips: Clam most closely resembles native sphaeriidae (fingernail) clams, however those are smaller (6-14 mm), more oval in shape, cream colored, have fine growth rings, lack serrations on the lateral teeth and are found completely buried in the sediment.

• Anatomy: Typical oval-triangular shape, with a dorsal “beak” or umbo at the peak of the shell, the nacre (or “mother of pearl layer) is typically white-bluish white in color, 1-2 pair of small, elongated and finely serrated lateral “teeth” that extend on either side from the umbo part way down on the inside edge of each valve

• Misc/General: Less than 50 mm, outside of the shell is normally yellow-green with concentric rings, color can flake, leaving white spots, lightly purple on the inside

• Adaptive anatomy:

Introduction: First detected in US waters in 1938 in the Columbia River, Washington.

• How introduced: Where/when: Assumed to have been imported as a food source for the immigrating Chinese population. Alternatively, it may have come in with the importation of the Giant Pacific oyster also from the Asia.

• How spread: Secondary dispersal likely involves human activity, including bait bucket introductions, accidental introductions associated with imported aquaculture species, and intentional introductions by people who buy them as a food item in markets. Larval clams can attach to vegetation, floating debris for long distance dispersal.

Life Cycle: Adults can live 3‐4 years. Larval clams are brooded on the gill where they transform into juveniles in about 4-5 days

• Egg:

• Larval Clams:

• Reproduction: Adults typically reproduce two times a year, although some populations have been observed reproducing more often under optimal situations. A single adult can produce 1000 – 100,000 juveniles per year. Egg fertilization is internal.

• What makes it so good at reproducing?: Adult Corbicula are simultaneous hermaphrodites (both male and female) that are capable of both cross and self‐fertilization; thus, it takes only 1 individual to start a population

Ecology:

• Diet: Filter feeder that removes particles from the water column

• Behavior:

• Niche:

• Trophic Level:

Native habitat: Freshwaters of eastern and southern Asia (also occurs naturally in Africa)

• Characteristics of said habitat:

Where it’s a problem (“new” habitat):

• Characteristics of new habitat: Corbicula can live in a variety of substrates, but prefers sand and gravel, over silt hard surfaces. Corbicula is less tolerant than native mussels to environmental fluctuations. It is extremely sensitive to low oxygen conditions, and consequently its distribution is restricted to well‐oxygenated streams and lake shallows.

Preventative measures: Screens and traps are used to prevent colonization, and benthic barriers have been demonstrated to be effective for short-term control, but non-target mortality may be high

• Laws and effectiveness:

• Control measures and effectiveness: Eradication is not an option, emphasis on containment and spread prevention. Diver assisted suction removal and bottom barriers are being researched. Chemical molluscicides are available, but are not species-specific, may harm native species to a greater extent

• Damage (why it’s a problem): Large numbers, either dead or alive, clog water intake pipes used in power and water industries, and the cost of removing them is estimated at about a billion US dollars each year. Because they can reproduce extremely rapidly, they compete with native species for food and space. Corbicula filters out phytoplankton and other particles suspended in the water that are also important food sources for other filter‐feeding organisms. Excrete significant amounts of inorganic nutrients, particularly nitrogen that, in turn, can stimulate the growth of algae and macrophytes.

Asian Shore Crab (Hemigrapsus sanguineus)

• Taxonomy: Kingdom-Animalia; Phylum-Arthropoda; Subphylum-Crustacea; Class-Malacostraca; Order-Decapoda; Infraorder-Brachyura; Family-Varunidae; Genus-Hemigrapsus; Species-H. sanguineus

Identification Tips: Males have fleshy bulb-like structure at base of movable finger on claw. May be mistaken for several other crabs in New England, including the European green crab, the Atlantic mud crab and others. To differentiate the region’s crabs, take note of the carapace's shape and the number of marginal spines on each side.

• Anatomy:

May be mistaken for several other crabs in New England, including the European green crab, the Atlantic mud crab and others. To differentiate the region’s crabs, take note of the carapace's shape and the number of marginal spines on each side.

• Carapace: Adults range from 35 mm - 42 mm in carapace width. Green to purple to orange-brown to red. Squareish, with 3 spines on each side of carapace.

• Body: It has light and dark bands along its legs and red spots on its claws.

• Eyes:

• Mouth:

• Misc/General: About 1.5 inches long or less

• Adaptive anatomy: Secretes thread from gills that allows it to float down the current

Introduction: First discovered: 1988, Cape May County, New Jersey

• How introduced: Where/when: Most likely introduced through ballast water

• How spread: Free-floating larvae can be transported over long distances during the month that it takes them to develop into juveniles and settle out of the water column

Life Cycle: Lifespan of 3-5 years

• Egg:

• Larvae:

• Reproduction: Highly reproductive, breeding from May to September, with females capable of producing three to four clutches per season, each containing up to 50,000 eggs.

• General Reproduction:

• What makes it so good at reproducing?: Capable of reproducing multiple times in a season.

Ecology:

• Diet: Opportunistic omnivore (it feeds on macroalgae, salt marsh grass, larval and juvenile fish, and small invertebrates)

• Behavior:

• Niche: Consumed by blue crab, rock crab, seagulls, and rock fish

• Trophic Level: Primary consumer

Native habitat: Western Pacific Ocean from Russia, along the Korean and Chinese coasts to Hong Kong, and the Japanese archipelago

• Characteristics of said habitat: Versatile, inhabits any shallow hard-bottom intertidal or sometimes subtidal habitat. They can live on artificial structures and on mussel beds and oyster reefs.

Where it’s a problem (“new” habitat):

• Characteristics of new habitat:

Preventative measures: Tracking the shore crab's spread along the coastline, ballast water management

• Laws and effectiveness: Not prohibited by TPWD

• Control measures and effectiveness: Parasites help control in native range only. Tautogs, drums, sheepshead and sea gulls prey upon crabs

• Damage (why it’s a problem): Could potentially negatively impact populations of such native species as fish, shellfish and other crabs by predation and by general food web effects. Voracious appetite and has been known to feed on commercially important species, such as larval lobsters. Due to rapid reproduction, they easily outnumber local rock crabs, and have the potential to displace them entirely.

Asian Swamp Eel (Monopterus albus)

• Taxonomy: Kingdom-Animalia; Phylum-Chordata; Class-Actinopterygii; Order-Synbranchiformes; Family-Synbranchidae; Genus-Monopterus; Species-M. albus

Identification Tips:

• Anatomy:

• Legs:

• Body:

• Eyes:

• Mouth:

• Misc/General: Nocturnal;

• Adaptive anatomy: Can breathe air, using atmospheric oxygen absorbed via a vascularized breathing apparatus at the rear of their mouths

Introduction: First found in 1994 in three spring-fed impoundments in Georgia.

• How introduced: Where/when: Hawaii in early 1900s; Continental in mid 1990s; imported as food source and for aquarium trade.

• How spread:

Life Cycle:

• Egg: Laid in free floating nest in shallow water;

• Larvae:

• Pupa: (Nymph can replace Larvae/Pupa)

• Reproduction:

• General Reproduction:Sequential hermaphrodite: all individuals are born and mature as females and some later transform into males

• What makes it so good at reproducing?:

Ecology:

• Diet:Crayfish; shrimp; worms; frogs; tadpoles; other fish;

• Behavior:

• Niche:

• Trophic Level:

Native habitat: Asia, from northern India and Burma to China

• Characteristics of said habitat: Tropical/temperate freshwater. Found in slowly moving waters. They often burrow into soft sediments or occupy crevices and small space

Where it’s a problem (“new” habitat):

• Characteristics of new habitat:

Preventative measures:

• Laws and effectiveness:

• Control measures and effectiveness:

• Damage (why it’s a problem):

Chinese Mitten Crab (Eriocheir sinensis)

• Taxonomy: Kingdom-Animalia; Phylum-Arthropoda; Subphylum-Crustacea; Class-Malacostraca; Order-Decapoda; Infraorder-Brachyura; Family-Varunidae; Genus-Eriocheir; Species-E. sinensis

Identification Tips: Male crabs have a narrow, triangular abdomen, while the female has a much broader abdomen. Recognizable hairy claws.

• Anatomy:

• Legs: Eight sharp pointed walking legs, no swimming legs, twice as long as the carapace is wide

• Carapace: Up to four inches wide, are light brown to olive color

• Claws: Equal size with white tips and hair

• Mouth:

• Misc/General:

• Adaptive anatomy:

Introduction: Introduced to US in: 1991 (West Coast); 2005 (East Coast)

• How introduced: Where/when: Introduced through ship ballast water and live release

• How spread:

Life Cycle: Larvae are suspended in the water column until late winter to early summer when they settle to the bottom and begin upstream migration. After spending 1-4 years in fresh or brackish water, males and females migrate downstream and reach sexual maturity in brackish waters of the estuary. Catadromous; life cycle is characterized by migrations in waters with changing salinities

• Egg:

• Larvae: Planktonic for approximately 1-2 months, developing in marine waters. They pass through five zoeal stages before metamorphosis to the megalopa stage

• Reproduction: The downstream or spawning migration occurs during late summer and into the fall. Males reach the brackish water zone of the estuary first and mating begins as soon as the females arrive.

• General Reproduction:

• What makes it so good at reproducing?:

Ecology:

• Diet:

• Behavior:

• Niche:

• Trophic Level:

Native habitat: Pacific coast of China and Korea, East Asia

• Characteristics of said habitat: Aquatic biomes: Rivers and streams, coastal, brackish (salty) water

Where it’s a problem (“new” habitat):

• Characteristics of new habitat:

Preventative measures:

• Laws and effectiveness: Generally illegal to import, transport, or possess live Chinese mitten crabs in the US

• Control measures and effectiveness: Are edible, and a new source of crab for the Chinese market, import unwanted crabs from Europe to replenish local purebred stock. China introduced vending machines to sell the crab in the subways.

• Damage (why it’s a problem): Interfere with fish salvage operations, fish passage facilities, water treatment plants, and power plants. Aggressive and may compete with native blue crab and local species. Their burrowing habits threaten stream bank and earthen dam stability, promote erosion and habitat loss. Crabs clog drainage systems, destroy fishing nets, hurt native fish species and damage local dams. They eat Salmon, Trout and Sturgeon eggs, and carry the oriental lung fluke.

Clubbed Tunicate (Styela clava)

• Taxonomy: Kingdom-Animalia; Phylum-Chordata; Subphylum-Tunicata; Class-Ascidiacea, Order-Stolidobranchia; Family-Styelidae; Genus-Styela; Species-S. clava

Identification Tips: There are two easily identifiable siphons, an incurrent and an excurrent. The two siphons usually have longitudinal bands alternating between reddish purple and tan

• Anatomy:

• Body: Tough leathery, brownish outer skin (or tunic) shows conspicuous bumps and often wrinkled swellings at the top (posterior) of the body and longitudinal ridges on the bottom (dorsal) part

• Eyes:

• Mouth:

• Misc/General: Can be about 5-6" long

• Adaptive anatomy: Siphons able to retract when animal is disturbed. Adult Styela have tough leathery bodies and may contain chemicals that deter predators

Introduction: First observed on the Pacific coast in the 1930s

• How introduced: Where/when: Probably introduced accidentally on the hulls of ships or with imported oysters

• How spread: Through ships' hulls and oyster importations.

Life Cycle: Can live 2 to 3 years and grow to 6 inches in length. It reaches sexual maturity within 10 months at about 3.5 inches and is capable of reproducing several times during its lifetime.

• Egg:

• Larvae: Larvae are planktonic for only one to three days before attaching to a hard substrate in spring and summer to metamorphose into a sessile adult.
• Reproduction:

• General Reproduction:Hermaphroditic, meaning that it contains both male and female organs. However the male and female parts of each individual do not mature at the same time, so it does not self fertilize

• What makes it so good at reproducing?:

Ecology:

• Diet: Pumps water in through the incurrent siphon, filters out oxygen and feeds on small organisms such as phytoplankton, zooplankton, oyster and mussel larvae

• Behavior:

• Niche:

• Trophic Level:

Native habitat: Eastern Asia

• Characteristics of said habitat: The tunicate attaches directly to a variety of substrates such as rock, wood, shells, but especially preferring artificial structures in protected waters such as pilings, docks, mooring lines, shellfish, aquaculture gear and boat hulls. Lives in mostly in shallow seawater and can live in water as deep as 25 metres.

Where it’s a problem (“new” habitat):

• Characteristics of new habitat:

Preventative measures:

• Laws and effectiveness:

• Control measures and effectiveness: Hand removal (picking or scraping the organism from its point of attachment) is the most reliable control method, but costly in terms of time and effort. Other ways of killing Styela clava involve lengthy exposure to air and/or extreme temperatures. Introduction of common shore crab in cages surrounding the sea squirt was not successful as a control agent.

• Damage (why it’s a problem): The sea squirt competes for space and food with native and aquaculture species (e.g., mussels, oysters). It can also be a nuisance by fouling marine farming lines, vessel hulls, and other structures.

Eurasian Ruffe (Gymnocephalus cernuus)

• Taxonomy: Kingdom-Animalia; Phylum-Chordata; Class-Actinopterygii; Order-Perciformes; Family-Percidae; Genus-Gymnocephalus; Species-G. cernuus

Identification Tips: Has 12–19 dorsal spines followed by 11–16 soft dorsal rays

• Anatomy: Fused dorsal fins; the caudal fin has 16–17 rays

• Body: Olive-brown to golden-brown on its back with yellowish white undersides

• Eyes:

• Mouth: Slightly down turned

• Misc/General: small fish, reaching 10 inches in length

• Adaptive anatomy: Their well-developed sensory system allows them to feed at night as well as to hide in darkness to avoid predators

Introduction: Possibly as early as 1982-1983.

• How introduced: Where/when: Probably introduced via ship ballast water discharged from a vessel arriving from a Eurasian port. 1986, Eurasian ruffe was collected from St. Louis River where it forms the border between Minnesota and Wisconsin. By 1994, species were found in Saxon Harbor of Wisconsin and in Michigan. First sighting in Lake Huron was in 1995. Found in Lake Michigan in 2002

• How spread: Ruffe has expanded its range in Europe, likely due to the construction of canals and the use of ruffe as bait. Within the Great Lakes, species spread may have been augmented by intra-lake shipping transport.

Life Cycle: Live an average of 7 years but have been known to live up to 11 years

• Egg: The eggs will hatch in 5 to 12 days

• Larvae:

• Reproduction: Maturing quickly especially in warm water, a female can start reproducing at age 2 and a male after just one year. They can spawn in a wide range of habitats and temperatures and on just about any substrate.

• General Reproduction:

• What makes it so good at reproducing?:

Ecology:

• Diet: Feeds on aquatic insects, bottom dwelling organisms, and occasionally the eggs

of other fish

• Behavior:

• Niche:

• Trophic Level:

Native habitat: Northern Europe and Asia, from France to eastern Siberia

• Characteristics of said habitat: Found in fresh and brackish water. They do well in a variety of habitat types including lakes, large and small rivers, estuaries, and ponds.

Where it’s a problem (“new” habitat):

• Characteristics of new habitat:

Preventative measures:

• Laws and effectiveness: Effective ballast water laws are needed to prevent more ruffe from being introduced.

• Control measures and effectiveness: Native predator population management has shown mixed results; they generally prefer native prey and will reduce native prey species and then turn to the ruffe. Strategies currently being considered include: increased predation, ballast water management, population reductions w/ fish toxicants, and baitfish management.

• Damage (why it’s a problem): Competes with other fish for food and space. Because they have high fecundity, rapid growth, and the ability to survive in a wide range of habitat types, ruffe can quickly dominate an area.

European Green Crab (Carcinus maenas)

• Taxonomy: Kingdom-Animalia; Phylum-Arthropoda; Subphylum-Crustacea; Class-Malacostraca; Order-Decapoda; Infraorder-Brachyura; Family-Portunidae; Genus-Carcinus; Species-C. maenas

Identification Tips:

• Similar species: dungeness crab, helmet crab
  • Helmet crabs have stiff hairs covering their entire body, unlike European green crabs.
  • Dungeness crabs have 10 small spines, whereas European green crabs have 5 larger spines.

• Anatomy:

• Legs: Flat rear leg

• Body: There are 5 spines on each side of the front of the shell, and 3 bumps between the eyes. Can be four inches across.

• Eyes:

• Mouth:

• Misc/General: Males molt more often than females and grow larger. Green or red.

• Adaptive anatomy: They can also tolerate wide ranges of salinities (4-54 ppt) and temperatures (0-33 °C). Can also survive upstream of river mouths in some estuarine environments

Introduction: Introduced to US in 1817 (East Coast); 1980s (West Coast) via ballast water, hull fouling, or intentional releases

• How introduced: Where/when: By the mid 1900s, it had spread north into Canada (Nova Scotia)

• How spread:

Life Cycle: Typically live between 4-7 years.

• Egg: The newly hatched eggs drift in the water column for up to 90 days until they turn into what look like small crabs and settle to the bottom.

• Larvae: The new larvae of European green crab, or the first stage zoea, aggregate in surface waters during the ebb tide at night when current velocities are highest. After a period of growth and development in the open sea (about two weeks), megalopae, the last larval stage of the crab, aggregate at night in surface waters during flood.

• Reproduction: Mating takes place after the females molt from April to November, but mainly from June to October. Because of their thicker shells and stronger claws, male red European green crabs compete more successfully for mates than green males. They produce many offspring: females are capable of spawning up to 185,000 eggs per year.

• General Reproduction:

• What makes it so good at reproducing?:

Ecology:

• Diet: Eats clams, mussels, oysters, scallops and even small lobster. Eating habits are the undersea equivalent of a 'scorched earth policy', eating most of what is in its path.

• Behavior:

• Niche:

• Trophic Level:

Native habitat: Native to the Atlantic coast of Europe and northern Africa, from Norway and the British Isles south to Mauritania.

• Characteristics of said habitat: Rocky shores, cobble beaches, sandflats, and tidal marshes. Often be found near eelgrass beds or other shoreline vegetation

Where it’s a problem (“new” habitat):

• Characteristics of new habitat:

Preventative measures:

• Laws and effectiveness: Prohibited. In 1998, the state completed the Aquatic Nuisance Species Management Plan called for in Section 1204 of the National Invasive Species Act of 1996.

• Control measures and effectiveness: Pyramid shaped wire mesh traps that are baited with fish and set in the water attached to buoys. Bio control - introducing the green crab’s natural European nemesis, the Sacculina carcini barnacle– which pierces the crab’s exoskeleton and causes sterility.

• Damage (why it’s a problem): Feed on the larvae of other crab species devastating their near shore nurseries. Pose a direct threat to shorebirds, as they have similar diets. Eat hundreds of species and are a voracious predator difficult to stop once they have established a foothold in a biotope. European green crab has the potential to out compete a Dungeness crab of approximately equal size for both food and habitat

Lionfish (Pterois volitans)

• Taxonomy: Kingdom-Animalia; Phylum-Chordata; Class-Actinopterygii; Order-Scorpaeniformes; Family-Scorpaenidae; Subfamily-Pteroinae; Genus-Pterois; Species-P. volitans

Identification Tips: 13 venomous spines are grooved and covered with a skin-like tissue along the front of the dorsal fin, 2 venomous spines located on the pelvic fins, 3 venomous spines are located along the front edge of the anal fin, pectoral fins and the tail fin do not contain venomous spines.

• Anatomy:

• Body: White stripes alternated with red/maroon/brown stripes.

• Eyes:

• Mouth:

• Misc/General: Can grow as large as 47 cm (18.5 in), while juveniles are typically shorter than 1 in (2.5 cm)

• Adaptive anatomy: Venomous spines

Introduction: First introduced off the Florida coast in the early to mid-1990s

• How introduced: Where/when: Introduced from aquarium trade.

• How spread:

Life Cycle: Can reach maturity in less than a year, growth slows as they get bigger, males mature at approx. 4 inches, females at 7 inches. Lifespan around 10 years.

• Egg: Two egg masses of about 12,000 to 15,000 eggs each are released, then fertilized before floating to the surface

• Larvae: Large head, a long, triangular snout, long, serrated head spines, large pelvic spine, coloration only in the pelvic fins, hatch 36 hrs after fertilization

• Pupa: (Nymph can replace Larvae/Pupa)

• Reproduction: Reproduce monthly, quickly disperse during their larval stage

• General Reproduction: One male with several females, only showing sexual dimorphism during reproduction, typically around nightfall and continuing through the night.

• What makes it so good at reproducing?:

Ecology:

• Diet: Marine fish, invertebrate species. Prey on more than 70 marine fish and invertebrate species: yellowtail snapper, Nassau grouper, parrotfish, banded coral shrimp, and cleaner species

• Behavior:

• Niche:

• Trophic Level:

Native habitat: Indo-Pacific region, West and central Pacific and off the coast of West Australia

• Characteristics of said habitat:

Where it’s a problem (“new” habitat):

• Characteristics of new habitat:

Preventative measures:

• Laws and effectiveness:

• Control measures and effectiveness: Harvest and consumption of lionfish. No definitive predators.

• Damage (why it’s a problem): Outcompetes similar fish and having a varied diet, drastically changing and disrupting the food chains holding the marine ecosystems together, declines in diversity of coral reef areas

Northern Snakehead (Channa argus)

• Taxonomy: Kingdom-Animalia; Phylum-Chordata; Class-Actinopterygii; Order-Perciformes; Family-Channidae; Genus-Channa; Species-C. argus
• Similar species: North American bowfin, blotched snakehead, burbot
  • North American bowfin is distinguished by a rounded tail and an eyespot near the tail in males.
  • Blotched snakehead is distinguished by its car-like markings on the caudal peduncle.
  • Burbot is distinguished by a split dorsal fin and a single barbel on the lower jaw.

Identification Tips: Characteristic flattened head, many sharp teeth

• Anatomy:

• Body: Flattened head; anterior nostrils are present and tubular; dorsal and anal fins are elongated, fins are supported only by rays.

• Eyes: Eyes located in a dorsolateral position on the anterior part of the head

• Mouth: Many sharp teeth, large mouth reaching far behind eyes.

• Misc/General: Golden tan to pale brown with dark blotches, coloration is the same between juveniles and adults. Maximum size exceeds 85 cm (33 inches), grows to a length up to 40 in (1.0 m), with one report of 60 in (1.5 m), weigh up to 17 lb 6 oz (8 kg)

• Adaptive anatomy: Capable of breathing outside of water for short periods of time.

Introduction: First discovered in the United States in California in 1997

• How introduced: Where/when:

• How spread: Northern snakehead fish can spread by swimming underwater and are also capable of breathing out of the water to move short distances on land.

Life Cycle:

• Egg: Eggs hatch in one to two days during the summer, parents guard the young until they begin to feed

• Larvae:

• Pupa: (Nymph can replace Larvae/Pupa)

• Reproduction: Spawn multiple times each year,releasing tens of thousands of eggs each time

• General Reproduction: Build spawning nests in aquatic vegetation, discharge eggs over nest, externally fertilized by males.

• What makes it so good at reproducing?:

Ecology:

• Diet: Feed on zooplankton then begin consuming other fish larvae when they are less than an inch long

• Behavior:

• Niche:

• Trophic Level:

Native habitat: Eastern Asia: China, Russia and Korea

• Characteristics of said habitat: Live in freshwater streams, rivers, wetlands, or ponds. They prefer low moving to stagnant waters. Snakeheads can survive the cold winters and low oxygen environment.

Where it’s a problem (“new” habitat):

• Characteristics of new habitat:

Preventative measures:

• Laws and effectiveness: Under the Federal Lacey Act, these fish and viable eggs cannot be moved through importation or interstate transport

• Control measures and effectiveness: Rotenone: surface spray application and injected underwater over the entire pond

• Damage (why it’s a problem): Compete with native species for food and habitat. Eat zooplankton, insect larvae, small crustaceans, fry of fish, fish, crustaceans, frogs, small reptiles, show significant diet overlap with largemouth bass (Micropterus salmoides). Disrupt recreational and commercial fishing, harm native fish and wildlife, and impact our economy

New Zealand Mud Snail (Potamopyrgus antipodarum)

• Taxonomy: Kingdom-Animalia; Phylum-Mollusca; Class-Gastropoda; Superfamily-Rissooidea; Family-Hydrobiidae; Genus-Potamopyrgus; Species-P. antipodarum

Identification Tips:

• Anatomy:

• Legs:

• Body:

• Eyes:

• Mouth:

• Misc/General:

• Adaptive anatomy:

Introduction:

• How introduced: Where/when:

• How spread:

Life Cycle:

• Egg:

• Larvae:

• Pupa: (Nymph can replace Larvae/Pupa)

• Reproduction:

• General Reproduction:

• What makes it so good at reproducing?:

Ecology:

• Diet:

• Behavior:

• Niche:

• Trophic Level:

Native habitat:

• Characteristics of said habitat:

Where it’s a problem (“new” habitat):

• Characteristics of new habitat:

Preventative measures:

• Laws and effectiveness:

• Control measures and effectiveness:

• Damage (why it’s a problem):

Nutria (Myocastor coypus)

• Taxonomy: Kingdom-Animalia; Phylum-Chordata; Class-Mammalia; Order-Rodentia; Family-Myocastoridae; Genus-Myocastor; Species-M. coypus

Identification Tips:

• Anatomy:

• Legs:

• Body:

• Eyes:

• Mouth:

• Misc/General:

• Adaptive anatomy:

Introduction:

• How introduced: Where/when:

• How spread:

Life Cycle:

• Egg:

• Larvae:

• Pupa: (Nymph can replace Larvae/Pupa)

• Reproduction:

• General Reproduction:

• What makes it so good at reproducing?:

Ecology:

• Diet:

• Behavior:

• Niche:

• Trophic Level:

Native habitat:

• Characteristics of said habitat:

Where it’s a problem (“new” habitat):

• Characteristics of new habitat:

Preventative measures:

• Laws and effectiveness:

• Control measures and effectiveness:

• Damage (why it’s a problem):

Quagga Mussel (Dreissena bugensis)

• Taxonomy: Kingdom-Animalia; Phylum-Mollusca; Class-Bivalvia; Subclass-Heterodonta; Order-Veneroida; Superfamily-Dreissenoidae; Family-Dreissenidae; Genus-Dreissena; Species-D. bugensis

Identification Tips:

• Anatomy:

• Legs:

• Body:

• Eyes:

• Mouth:

• Misc/General:

• Adaptive anatomy:

Introduction:

• How introduced: Where/when:

• How spread:

Life Cycle:

• Egg:

• Larvae:

• Pupa: (Nymph can replace Larvae/Pupa)

• Reproduction:

• General Reproduction:

• What makes it so good at reproducing?:

Ecology:

• Diet:

• Behavior:

• Niche:

• Trophic Level:

Native habitat:

• Characteristics of said habitat:

Where it’s a problem (“new” habitat):

• Characteristics of new habitat:

Preventative measures:

• Laws and effectiveness:

• Control measures and effectiveness:

• Damage (why it’s a problem):

Round Goby (Neogobius melanostomus)

• Taxonomy: Kingdom-Animalia; Phylum-Chordata; Class-Actinopterygii; Order-Perciformes; Suborder-Gobioidei; Family-Gobiidae; Subfamily-Benthophilinae; Genus-Neogobius; Species-N. melanostomus
• Native to all shallow water regions of the Black Sea, the Caspian Sea, the Marmara Sea and in all areas of the Sea of Azov.
• Introduction:
  • Was first recorded in North America in 1990 in the St Clair River at Sarnia, Ontario.
  • Likely introduced accidentally in ballast water.

Identification Tips:

• Anatomy:

• Legs:

• Body:

• Eyes:

• Mouth:

• Misc/General:

• Adaptive anatomy:

Introduction:

• How introduced: Where/when:

• How spread:

Life Cycle:

• Egg:

• Larvae:

• Pupa: (Nymph can replace Larvae/Pupa)

• Reproduction:

• General Reproduction:

• What makes it so good at reproducing?:

Ecology:

• Diet:

• Behavior:

• Niche:

• Trophic Level:

Native habitat:

• Characteristics of said habitat:

Where it’s a problem (“new” habitat):

• Characteristics of new habitat:

Preventative measures:

• Laws and effectiveness:

• Control measures and effectiveness:

• Damage (why it’s a problem):

Rusty Crayfish (Orconectes rusticus)

• Taxonomy: Kingdom-Animalia; Phylum-Arthropoda; Subphylum-Crustacea; Class-Malacostraca; Order-Decapoda; Superfamily-Astacoidea; Family-Cambaridae; Genus-Orconectes; Species-O. rusticus

Identification Tips: Greenish brown to brownish red on upper side; single brown spots on each side near middle

• Anatomy:

• Legs:

• Body:

• Eyes:

• Mouth:

• Misc/General:

• Adaptive anatomy:

Introduction:

• How introduced: Where/when:

• How spread:

Life Cycle:

• Egg:

• Larvae:

• Pupa: (Nymph can replace Larvae/Pupa)

• Reproduction:

• General Reproduction:

• What makes it so good at reproducing?:

Ecology:

• Diet:

• Behavior:

• Niche:

• Trophic Level:

Native habitat:

• Characteristics of said habitat:

Where it’s a problem (“new” habitat):

• Characteristics of new habitat:

Preventative measures:

• Laws and effectiveness:

• Control measures and effectiveness: Chemicals will work, but kill ALL crayfish; prevent introduction by educating anglers, etc.; human consumption;

• Damage (why it’s a problem): Reduces native crayfish and vegetation populations;

Sea Lamprey (Petromyzon marinus)

• Taxonomy: Kingdom-Animalia; Phylum-Chordata; Superclass-Agnatha; Class-Hyperoartia (Petromyzontida); Order-Petromyzontiformes; Family-Petromyzontidae; Genus-Petromyzon; Species-P. marinus
• Similar species: silver lamprey, chestnut lamprey, American brook lamprey, northern brook lamprey
  • Silver lampreys, chestnut lampreys, and northern brook lampreys have a single dorsal fin that is continuous with the caudal fin, unlike the sea lamprey which has a separated dorsal fin with two lobes. In addition, the 2nd dorsal fin lobe is separated from the caudal fin by a deep notch.
  • American brook lampreys have a dorsal fin that is separated by a deep notch, and the dorsal and caudal fins are nearly separate. This is unlike the sea lamprey, whose dorsal fin has well-separated lobes and whose 2nd dorsal fin lobe is separated from the caudal fin by only a deep notch.

Identification Tips: Smooth, scaleless skin; two dorsal fins; 7 distinct gills along sides

• Anatomy: No lateral line; no vertebrae; no swim bladder; no paired fins

• Body:

• Eyes:

• Mouth: Jawless; sharp teeth surround a file-like tongue; large sucking disk

• Misc/General:

• Adaptive anatomy: Good sense of smell

Introduction: Through manmade locks and shipping canals; Niagara Falls used to be barrier against lampreys

• How introduced: Where/when: First observed Lake Ontario in 1830; Erie in 1921; St. Clair ‘34; Lake MI ‘36, Huron ‘37; Superior ‘38

• How spread:

Life Cycle:

• Egg:

• Larvae: Small, wormlike larvae swept downstream and burrow into sand; feed on carried bottom debris and algae; 4-6 years grow to 6 inches; then transform into parasitic phase; called ammocoetes

• Pupa: (Nymph can replace Larvae/Pupa)

• Reproduction:

• General Reproduction:

• What makes it so good at reproducing?:

Ecology:

• Diet: Attach to fish with sucking mouth and suck out fluids; parasitic; can kill up to 40 pounds of fish over lifetime;

• Behavior:

• Niche:

• Trophic Level:

Native habitat: Atlantic Ocean

• Characteristics of said habitat:

Where it’s a problem (“new” habitat): Great Lakes

• Characteristics of new habitat:

Preventative measures:

• Laws and effectiveness:

• Control measures and effectiveness: Lampricide: TFM in tributaries and Bayluscide on deltas (targets larvae); barriers;

• Damage (why it’s a problem): Kill fish (lake trout, whitefish, chub, salmon, rainbow trout, burbot, walleye, catfish, etc.)

Sea Squirt (Didemnum vexillum)

• Taxonomy: Kingdom-Animalia; Phylum-Chordata; Subphylum-Tunicata; Class-Ascidiacea; Order-Aplousobranchia; Family-Didemnidae; Genus-Didemnum; Species-D. vexillum

Identification Tips: Immobile; long and club shaped on a tough stalk; tough/rumpled/nobbly/leathery;

• Anatomy: invertebrate; brownish-white, yellowish-brown, reddish-brown; look furry

• Legs:

• Body:

• Eyes:

• Mouth:

• Misc/General: “solitary”, which means each has own stalk and adheres to substrate separately; live for 2 years and grow up to 160 mm

• Adaptive anatomy:

Introduction:

• How introduced: Where/when: Probably accidentally on hulls of ships or with imported oysters; First seen on Pacific Coast around 1930

• How spread:

Life Cycle:

• Egg:

• Larvae:

• Pupa: (Nymph can replace Larvae/Pupa)

• Reproduction: Hermaphroditic

• General Reproduction:

• What makes it so good at reproducing?:

Ecology:

• Diet: Zooplankton; detritus; phytoplankton

• Behavior:

• Niche:

• Trophic Level:

Native habitat: Eastern Asia (Japan/China)

• Characteristics of said habitat:

Where it’s a problem (“new” habitat):

• Characteristics of new habitat:

Preventative measures:

• Laws and effectiveness:

• Control measures and effectiveness: Attempted to market as “delicacy” to eat- Korean dish called Mideodok Chim; scraping or soaking in vinegar

• Damage (why it’s a problem): Displaces native species (oysters, etc.); fouls hulls and shellfish farms by settling on ropes and shellfish;

Spiny Water Flea (Bythotrephes longimanus)

• Taxonomy: Kingdom-Animalia; Phylum-Arthropoda; Subphylum-Crustacea; Class-Branchiopoda; Order-Cladocera; Family-Cercopagididae; Genus-Bythotrephes; Species-B. longimanus

Identification Tips: Small crustacean; ½ inch long with barbed tail spine; parthenogenically produced (asexual) have kink in spine, sexually produced don’t;

• Anatomy:

• Legs:

• Body:

• Eyes: One large black or red eye

• Mouth:

• Misc/General:

• Adaptive anatomy:

Introduction:

• How introduced: Where/when: First found in Lake Huron in 1984; probably from ballast discharge

• How spread:

Life Cycle:

• Egg:

• Larvae:

• Pupa: (Nymph can replace Larvae/Pupa)

• Reproduction:

• General Reproduction:

• What makes it so good at reproducing?: Can produce both asexually and sexually;

Ecology:

• Diet:

• Behavior:

• Niche:

• Trophic Level:

Native habitat: Great Britain; Northern Europe

• Characteristics of said habitat:

Where it’s a problem (“new” habitat): Great Lakes

• Characteristics of new habitat:

Preventative measures:

• Laws and effectiveness:

• Control measures and effectiveness: Clean cables and reels; dispose of live bait in trash; drain water before leaving; ONLY SUCCESSFUL WAY is to prevent introduction

• Damage (why it’s a problem): Feeds on native zooplankton; fish fear the spiny tail so they won’t eat it

Veined Rapa Whelk (Rapana venosa)

• Taxonomy: Kingdom-Animalia; Phylum-Mollusca; Class-Gastropoda; Superfamily-Muricoidea; Family-Muricidae; Subfamily-Rapaninae; Genus-Rapana; Species-R. venosa

Identification Tips: Globose (rounded) shell; short spire and large whorl; distinctive black veins, easily distinguished by deep orange aperture and columella

• Anatomy:

• Legs:

• Body:

• Eyes:

• Mouth:

• Misc/General:

• Adaptive anatomy:

Introduction:

• How introduced: Where/when: Ballast water; eggs transported with marine products; discovered in lower Chesapeake Bay 1998

• How spread:

Life Cycle:

• Egg: Clusters; look like yellow shag carpet; 20-50 egg cases with 200-1000 eggs

• Larvae: Pelagic; after 4-6 weeks settle down

• Pupa: (Nymph can replace Larvae/Pupa)

• Reproduction:

• General Reproduction:

• What makes it so good at reproducing?:

Ecology:

• Diet: Smother prey with hinged part of shell, consume mollusks (oysters, clams)

• Behavior:

• Niche:

• Trophic Level:

Native habitat: Sea of Japan, Yellow Sea, Bohai Sea, East China Sea

• Characteristics of said habitat: Compact sandy bottoms (can burrow deep)

Where it’s a problem (“new” habitat):

• Characteristics of new habitat:

Preventative measures:

• Laws and effectiveness:

• Control measures and effectiveness:

• Damage (why it’s a problem): Eats a lot of prey, reducing food availability for others; can live up to 10 years and have no local predators

White Spotted Jellyfish (Phyllorhiza punctata)

• Taxonomy: Kingdom-Animalia; Phylum-Cnidaria; Class-Scyphozoa; Order-Rhizostomae; Family-Mastigiidae; Genus-Phyllorhiza; Species-P. punctata

Identification Tips: Bluish-brown with evenly distributed white spots;

• Anatomy:

• Appendages: 8, thick, transparent arms; large brown bundles of stinging cells; longer hanging transparent appendage

• Body:

• Eyes:

• Mouth:

• Misc/General: Bell may reach 50 cm in diameter;

• Adaptive anatomy:

Introduction:

• How introduced: Where/when: Ballast water; 1941-1945 into Pearl Harbor

• How spread:

Life Cycle:

• Egg:

• Larvae:

• Pupa: (Nymph can replace Larvae/Pupa)

• Reproduction:

• General Reproduction:

• What makes it so good at reproducing?:

Ecology:

• Diet: Filter feeders; don’t use venom; microscopic zooplankton;

• Behavior:

• Niche:

• Trophic Level:

Native habitat: Australia

• Characteristics of said habitat:

Where it’s a problem (“new” habitat):

• Characteristics of new habitat:

Preventative measures:

• Laws and effectiveness:

• Control measures and effectiveness:

• Damage (why it’s a problem): Swarms/smacks eat all plankton, leaving no food for native species

Zebra Mussel (Dreissena polymorpha)

• Taxonomy: Kingdom-Animalia; Phylum-Mollusca; Class-Bivalvia; Subclass-Heterodonta; Order-Veneroida; Superfamily-Dreissenoidae; Family-Dreissenidae; Genus-Dreissena; Species-D. polymorpha

Identification Tips: Small, fingernail sized; D-shaped; white interior; byssal threads

• Anatomy:

• Legs:

• Body:

• Eyes:

• Mouth:

• Misc/General:

• Adaptive anatomy: Byssal threads help it attach to hard surfaces;

Introduction:

• How introduced: Where/when: Ballast water dumping; Lake St. Claire in 1988

• How spread:

Life Cycle: 4-5 years long;

• Egg:

• Larvae:

• Pupa: (Nymph can replace Larvae/Pupa)

• Reproduction:

• General Reproduction:

• What makes it so good at reproducing?:

Ecology:

• Diet:

• Behavior:

• Niche:

• Trophic Level:

Native habitat: Caspian Sea

• Characteristics of said habitat:

Where it’s a problem (“new” habitat):

• Characteristics of new habitat:

Preventative measures:

• Laws and effectiveness:

• Control measures and effectiveness: UV rays, chemicals, electrical currents, and filters. Diving ducks and freshwater drum eat but cannot control; drain buckets and boats

• Damage (why it’s a problem): Competing for food; colonize native species’ shells and kill them; attach to and clog water intakes and pipes of power plants and water supply facilities