Psammonobiotus dziwnowi
Common Name:
A testate amoeba
Synonyms and Other Names:
Identification:
Amoebas in the family Psammonobiotidae have bilaterally symmetric tests (shells) of organic material covered in haphazardly arranged quartz shards. Particles on the test of P. dziwnowi are small and usually angular in outline. One or two pseudopods protrude through an opening at one end of the test surrounded by a flared, flat collar. Individuals are narrow and long; the length to width ratio of this species is approximately 2. The oral opening is located inside the collar, and the collar can be parallel to the test or bent at an angle of up to 45° (Golemansky 1974; Nicholls and MacIsaac 2004; Nicholls 2005).
Size:
This species is around 22–28 µm long, 12–15 µm wide, and 10 µm high, with a 8–10 µm wide collar
Native Range:
P. dziwnowi has only previously been recorded from the Baltic Sea (Golemansky 1973), but possibly originates from the Ponto-Caspian region (Black, Caspian, and Aral Sea basins) (Nicholls and MacIsaac 2004; Nicholls 2005).
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This map only depicts Great Lakes introductions.
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Great Lakes Nonindigenous Occurrences:
This species was first recorded from Lake Superior, Lake Huron, Lake Erie and Lake Ontario in 2002 (as "Psammanobiotus sp."; Nicholls and MacIsaac 2004).
Ecology:
Psammonobionts generally occur where interstitial water movement and oxygen supply are adequate. They attach to sand grains using the flat collar that is part of the test. The pseudopods protrude from the oral opening of the test for locomotion and feeding. Testate amoebas feed on bacteria and particulate organic matter. P. dziwnowi has been recorded from salinities of 2 ppt along the Baltic Sea coast (Nicholls and MacIsaac 2004).
Means of Introduction:
The most probable vector of introduction to the Great Lakes is ship ballast (Nicholls and MacIsaac 2004).
Status:
Established where found. It should be noted that Lake Michigan has not yet been surveyed for this organism (Nicholls and MacIsaac 2004).
Great Lakes Impacts:
Summary of species impacts derived from literature review. Click on an icon to find out more...
Current research on the environmental impact of Psammonobiotus dziwnowi in the Great Lakes is inadequate to support proper assessment.
Realized:
Psammonobiotus dziwnowi was first detected in the Great Lakes through surveys of beach sand in 2001 and 2002 at “moderate” numbers (63 individuals total) (Nicholls 2005, Nicholls and MacIsaac 2004). However, compared to abundance in marine beaches, densities of psammobiont testate rhizopods in the Great Lakes are relatively low (Nicholls and MacIsaac 2004).
Potential:
While the impacts of P. dziwnowi in the Great Lakes have not yet been studied, testate amoebae tend to prey upon and modify microbial populations, accelerate nutrient cycling, and be consumed by other organisms (e.g., Lousier and Parkinson 1984, Schönborn 1992). Furthermore, selective grazing by testate amoebae may influence microbial community taxonomic composition and metabolic activity (Bonkowski 2004, Sherr et al. 1992).
There is little or no evidence to support that Psammonobiotus dziwnowi has significant socio-economic impacts in the Great Lakes.
There is little or no evidence to support that Psammonobiotus dziwnowi has significant beneficial effects in the Great Lakes.
Potential:
In studies outside the Great Lakes, testate amoebae have been used as indicators of ecosystem condition and function (e.g., Fournier et al. 2012).
Management:
Regulations (pertaining to the Great Lakes)
There are no known regulations for this species.
Note: Check federal, state/provincial, and local regulations for the most up-to-date information.
Control
Biological
There are no known biological control methods for this species.
Physical
There are no known physical control methods for this species.
Chemical
There are no known chemical control methods for this species.
Note: Check state/provincial and local regulations for the most up-to-date information regarding permits for control methods. Follow all label instructions.
Remarks:
This species was originally referred to as Psammonobiotus sp. (Golemansky 1973, Nicholls and MacIsaac 2004). It was named P. dziwnowi by Nicholls (2005). Given the lack of research effort devoted to testate amoebae to date, this species may have been present in the Great Lakes for many decades prior to its discovery. However, Nicholls and MacIsaac (2004) also remark that the Psammanobiotus species, given their current distribution pattern, may be relatively recent arrivals to the Great Lakes.
References
(click for full reference list)
Author:
Kipp, R.M., A.K.Bogdanoff, and A. Fusaro.
Contributing Agencies:
Revision Date:
9/13/2019
Citation for this information:
Kipp, R.M., A.K.Bogdanoff, and A. Fusaro., 2024, Psammonobiotus dziwnowi: U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, and NOAA Great Lakes Aquatic Nonindigenous Species Information System, Ann Arbor, MI, https://nas.er.usgs.gov/queries/greatlakes/FactSheet.aspx?Species_ID=2654&Potential=N&Type=0&HUCNumber=DHuron, Revision Date: 9/13/2019, Access Date: 4/26/2024
This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.