Chesapeake Bay Introduced Species Database


Trapa natans

Common name(s):
Water Chestnut
Trapa natans (Water Chestnut) was a widespread Eurasian water plant with edible seeds, and was introduced to North America as an ornamental plant in the 19th century. In the 20th century, it formed great blooms, clogging waterways in the Great Lakes, Hudson River, and in the Potomac, and upper Bay. It was cleared by mechanical methods in the 1950s, but has reappeared in 1998 in the Bird and Sassafras River, Maryland, and in 2014 in Pohick Bay, Viriginia, on the Potomac. These blooms have been controlled by state agencies, with the help of volunteers.
Image courtesy of U.S. Army corps of Engineers 1977.



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Environmental Tolerances

 
For Survival
For Reproduction
Minimum
Maximum
Minimum
Maximum
Temperature (ºC)
null null null null
Salinity (‰)
0 1 0 1
Oxygen
hypoxic      
pH
null null    
Salinity Range
fresh-oligo


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Age and Growth

Male
Female
Minimum Adult Size (mm)
null null
Typical Adult Size (mm)
1500 1500
Maximum Adult Size (mm)
3050 3050
Typical Longevity (yrs)
0.5 0.5
Maximum Longevity (yrs)
null null


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Reproduction

Start
Peak
End
Reproductive Season
June --- July
Typical Number of Young
per Reproductive Event
219
Sexuality Mode(s)
monoecious
Mode(s) of Asexual Reproduction
Fertilization Type(s)
outcross-external
More than One Reproductive
Event per Year
no
Reproductive Strategy
semelparous
Egg/Seed Form


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Development

Minimum Typical Maximum
Egg/Seed Development Time (days)
null null null
Larval/Seed Development Period (days)
null 270 4285
Male Maturation Age (yrs)
null 0.25  
Female Maturation Age (yrs)
null null  
Larval/Seed Form  
seed


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Locomotion and Abundance in Chesapeake

Locomotion
Abundance
Larvae
sessile rare
Juveniles
sessile, floating rare
Adults
sessile, floating rare


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Habitat Preferences

Larvae
Juvenile
Adult
Primary Horizontal Habitats
fresh (non-tidal) marsh; fresh tidal marsh; unstructured; nontidal freshwater fresh (non-tidal) marsh; fresh tidal marsh; unstructured; nontidal freshwater fresh tidal marsh; unstructured; nontidal freshwater; grass bed
Secondary Horizontal Habitats
Reproductive Horizontal Habitats
n/a n/a fresh (non-tidal) marsh; fresh tidal marsh; unstructured; nontidal freshwater
Vertical Habitats
epibenthic neustonic neustonic
Substrate Type
silt; mud silt; mud silt; mud
Tidal Height Location
subtidal; low intertidal subtidal; low intertidal subtidal; low intertidal
Wave Exposure
low; protected
Water Flow
stagnant; slow


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Trophic Interactions

Larvae
Juveniles
Adults
Trophic Status
non-feeding primary producer primary producer
Common Food/Prey Items
Common Competitors
submerged aquatic vegetation (including Myriophyllum spicatum; Elodea canadensis; Elodea nuttali; Potamogeton pectinatus; Potamogeton perfoliatus; Potamogeton crispus; Zanichellia palustris; Najas minor; Najas guadalupensis; Heteranthera dubia; Vallisneria americana) submerged aquatic vegetation (including Myriophyllum spicatum; Elodea canadensis; Elodea nuttali; Potamogeton pectinatus; Potamogeton perfoliatus; Potamogeton crispus; Zanichellia palustris; Najas minor; Najas guadalupensis; Heteranthera dubia; Vallisneria americana)
Common Consumers


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Comments

Life History: Environmental Tolerances: Temperature- Trapa natans is and annualplant and overwinters as seed (Muenscher 1935; United States Army Corps of Engineers 1977). Salinity - This plant 'tolerates no salinity', and declined during droughts due to increased salinity (United States Army Corps of Engineers 1977), but it has been found in 'slightly brackish' water (Hurley 1990). Experimental studies of its salinity tolerance might be useful. Other Environmental Factors- This plant undergoes rapid leaf growth in response to nitrate addition (Tsuchiya and Iwakuma 1993).

Age and Growth: Adult Size - We assumed 'typical' size to be one-half the maximum. Longevity- We assume April gemination, and October dieback.

Reproduction: Typical Number of Young per Reproductive Event- A single plant produced 10-15 rosettes; 15-20 seeds per rosette (we chose midpoints; 12.5 X 17.5), (United States Army Corps of Engineers 1977).

Development: Larval Period Length- We assumed August seed set and April germination. Seeds are viable for up to 12 years (United States Army Corps of Engineers 1977).

Locomotion and Abundance: Mode(s) of Dispersal - The floating adults are chief mode of dispersal. The hooked, spiny seeds sink, but also can attach to floating objects, large animals, etc. The seeds are too large for bird dispersal (United States Army Corps of Engineers 1977).
Community Ecology: Habitat Preferences: Primary Horizontal Habitats- Trapa natans (Water Chestnut) is a floating plant, which can float freely or be rooted in the substrate, in shallow water (Hurley 1990). The United States Fish and Wildlife Service uses a system of codes to indicate the tendency of plants to occur in wetlands (R-1 Wetlands Indicator). Trapa natans has been assigned an R-1 value of 'OBL ', which is roughly equivalent to a 100% chance of this plant occurring in wetlands.(Natural Resources Conservation Service 2001). Vertical Habitats- The seeds sink, while adult plants float on the water surface (Hurley 1990). Substrate Types- This plant grows best where roots can drag in fine-granulated muds (Hurley 1990).


This data was last modified on Thursday, September 29th, 2005.
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