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Purple loosestrife
Location: Europe and Asia
Environmental impact: Dense growth crowds our other species
Method of introduction: In the 19th century, purple loosestrife was introduced to the northeastern United States and Canada. Its uses were for medicine and for decoration.
Perennial plant that is purple in color
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Eurasian Water Milfoil
Location of Origin: Native to Asia, Europe, and Africa. Invasive to the state of Wisconsin.
Life Cycle: Reproduces by fragmentation.
Extra Information: Plant with pink flowers and thread-like leaves.
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Water Hyacinth
Location of Origin: South America
Environmental Impact: Habitat for mosquitoes. Blocks sunlight from reaching native plants.
Method of Introduction: This species was introduced into the St. John's river in Florida shortly after the Industrial and Cotton Exposition in 1884. It soon spread throughout the southeast.
Distribution: this species is mainly a pest along the Atlantic and Pacific coastlines and the Mississippi River valley. It is absent from most of the great plains region.
Importance as Indicators: Tolerate high levels of pollution.
Ecology: Extremely fast growing
Life cycle: Reproduces by making stolons.
Extra Information: Free-floating plants with purple flowers.
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Zebra Mussel
Location of Origin: Eurasia
Environmental Impact: Ecological competition with the native species, responsible for clogged pipes and sewage
Method of Introduction: Attached to ships' ballasts, introduced into marine ecosystems
Distribution: Concentrated in Great Lakes area
Life cycle: Life span is 4-5 years in native environment (Eurasia), in Great Lakes lives maximum of 3 years. Maturity reached after one year. Spawning incited by temperature or abundance of phytoplankton. Stages of Life Cycle: Egg Stage, Veliger Stage, Post-Veliger Stage, Settling Stage. Egg Stage: Females produce 30,000-40,000 eggs at a time. Male zebra mussels sense eggs in water and release sperm into water which fertilize the eggs. Veliger Stage: Larvae are referred to as veligers, and emerge from eggs a few hours after males fertilize eggs. To maintain suspension in water, veligers develop cilia. Diet of veligers are plankton, and undergo growth spurts during this stage. Post-Veliger Stage:
Feeding habits: Filter-feeders
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Spiny Water Flea
Location of Origin: Northern Europe
Environmental Impact: Predation on zoo-plankton, competition with native species (i.e. perch, small crustaceans). Depletes population of zooplankton (keystone species), and the water flea population cannot be moderated by other fish, as spiny barbs on the flea make it inedible.
Method of Introduction: Accidentally introduced into waters through ballasts of ships.
Distribution: Concentrated in Great Lakes area
Life Cycle: Spiny Water Fleas are parthenogenetic, which means that it can interchange between being able to reproduce sexually and asexually. Females can produce a minimum of 10 offspring every two weeks. Vernal and autumnal activity only, eggs remain dormant until proper season, and water temperature rises. Eggs can withstand cold temperatures, which is why they survive dormancy through the winter.
Feeding Habits: Feeds on zooplankton such as Daphnia, and other smaller organisms.
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Asian tiger mosquito
Location of Origin: Asia
Environmental Impact: Aggressive biting of humans, vector of several viruses (i.e. West Nile Virus, Yellow Fever, St. Louis encephalitis, dengue fever, etc.)
Method of Introduction: Accidentally introduced into United States while importing Japanese tires.
Distribution: Concentrations in Southwest, Northeast United States.
Ecology: Eggs do not necessarily need to be laid in stagnant water, as larvae can develop in both still water and running water. Females normally lay eggs on sides of containers filled with water (i.e. tires, flowerpots, natural holes) and the eggs require rainfall to rise the water level and trigger the larvae to hatch. Larvae are called wigglers, actively feeding in the water, siphoning organic matter floating around. Larval stage lasts 5-10 days, and pupal stage lasts 2 days.
Life Cycle: Females require blood for egg development, and obtain it by sucking it out of its host(s) with an elongated proboscis. The bite is quick, so the reaction of a human attempting to swat it isn't fast enough to catch the fleeing mosquito. Males feed on nectar, sweet plant juices.
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Carp
Importance as Indicators: Increase turbidity by pulling out the roots of plants
Feeding Habits: Eat plankton and the eggs of other animals
Extra Information: Invasive to Mississippi River
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