Thalassiosira pseudonana (Hustedt) Hasle and Heimdal, (1957) 1970

Common Name: A centric diatom

Synonyms and Other Names:

Cyclotella nana



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Identification: This diatom can occur singly or in chains up to 6 cells long. It typically exhibits a ring of fultoportulae around the edge of the valve face, costae that may run from the middle of the valve face to its edges, and one labiate process. The central region of the valve face is often bounded by an irregular siliceous ring and may or may not exhibit central fultoportulae. The valve face is often striated radially and hexagonal to polygonal areolae are often apparent in the central region (Belcher and Swale 1977, 1986, Harris et al. 1995, Hasle 1976, Lange et al. 1983, Lowe and Busch 1975, Muylaert and Sabbe 1996, Sabater and Klee 1990).

Thalassiosira pseudonana can range in diameter from 2.5–15 µm (Belcher and Swale 1977, 1986, Harris et al. 1995, Hasle 1976, Lange et al. 1983, Lowe and Busch 1975, Muylaert and Sabbe 1996, Price et al. 1987).


Size: 2.5 to 15 microns


Native Range: Unclear. Thalassiosira pseudonana is considered widespread. It is known from freshwater habitats in Europe and the former USSR, brackish and coastal waters of Europe, coastal waters of Japan, coastal waters of Australia, coastal waters of India, the Argentine Sea, the Baltic Sea, coastal waters on both sides of North America, and a few inland habitats in North America (Ake-Castillo et al. 1999, Belcher and Swale 1977, 1986, Blinn et al. 1981, Genkal and Prokina 1981, Harris et al. 1995, Hasle 1978, Kiss 1984, 1996, Lange et al. 1983, Lowe and Busch 1975, Mills et al. 1993, Muylaert and Sabbe 1996, Raman and Prakash 1989).


Map Key
This map only depicts Great Lakes introductions.

 
Great Lakes Nonindigenous Occurrences: Thalassiosira pseudonana was recorded for the first time in the Lake Erie drainage in an Ohio artesian well in 1973, but it may have been present at an earlier date elsewhere in the Great Lakes drainage. It was later recorded from Lake Erie, Lake Ontario, Lake Michigan, and the Sandusky River, which flows into Lake Erie (Lowe and Kline 1976, Mills et al. 1993).


Table 1. Great Lakes region nonindigenous occurrences, the earliest and latest observations in each state/province, and the tally and names of HUCs with observations†. Names and dates are hyperlinked to their relevant specimen records. The list of references for all nonindigenous occurrences of Thalassiosira pseudonana are found here.

State/ProvinceFirst ObservedLast ObservedTotal HUCs with observations†HUCs with observations†
19781978*
NY199319931Lake Ontario
OH197319932Lake Erie; Sandusky

Table last updated 5/1/2024

† Populations may not be currently present.

* HUCs are not listed for areas where the observation(s) cannot be approximated to a HUC (e.g. state centroids or Canadian provinces).


Ecology: Thalassiosira pseudonana is a cosmopolitan species typically found in freshwater and coastal brackish habitats. It is usually a phytoplankton species but has also been recorded in the periphyton. It is eurythermal, experiencing good growth from 10–30°C, with an optimum around 21°C. Growth rates typically increase with increasing temperature, which confers T. pseudonana a competitive advantage at higher temperatures. Maximum abundance has been recorded in different regions of the world in late spring, summer, and late fall (Ferguson et al. 1976, Goldman and Ryther 1976, Harris et al. 1995, Hegseth and Saksaug 1983, Lowe and Busch 1975, Lowe and Kline 1976). The distribution and growth of T. pseudonana is primarily regulated by water temperature and day length (Brand et al. 1981, Ferguson et al. 1976, Hegseth and Skashaug 1983).

Thalassiosira pseudonana, like many diatom species, is capable of sexual reproduction. In general, the rate of reproduction increases with increasing temperature. It has a dormant stage that is most likely a physiological resting cell (Armbrust et al. 2001, Brand et al. 1981, McQuoid 2005). Growth can be limited by changes in concentrations of vitamin B-12, silicon, selenium, zinc, nitrogen, phosphorus, or other vitamins (Guillard et al. 1973, Maestrini et al. 1997, Miao and Wang 2006, Price et al. 1987, Swift and Taylor 1974, Sunda and Huntsman 1992, 2005).

Although non-toxic itself, this species is often associated with relatively polluted regions, places where chemical oxygen demand is elevated and nutrient concentrations are very high, and waters experiencing red tides (de Almeida and Gil 2001, Gao et al. 2006, Mallin et al. 1995, Raman and Prakash 1989, Weckstrom and Juggins 2006). Thalassiosira pseudonana grows well at pH of 7–8.8, but its growth rates are reduced at higher pH because CO2 becomes limiting (Chen and Durbin 1994). It is capable of quickly adapting to changes in irradiance by adjusting cell volume (Thompson et al. 1991).


Means of Introduction: Thalassiosira pseudonana was very likely introduced in ballast water to the Great Lakes basin. It was first discovered in an artesian well but was probably originally introduced elsewhere in the basin at a location more easily accessible to ships carrying ballast water (Mills et al. 1993).


Status: Established where recorded.


Great Lakes Impacts:
Summary of species impacts derived from literature review. Click on an icon to find out more...

Environmental

There is little or no evidence to support that Thalassiosira pseudonana has significant environmental impacts in the Great Lakes.

Potential:
Thalassiosira pseudonana has been found in the Great Lakes basin composing 31% of the periphyton community and 90% of the plankton community (Lowe and Busch 1975). McQuoid (2005) reported growth of T. pseudonana after 2 years in storage, indicating the presence of a dormant state that seems to be triggered by temperature and light cues. This dormant state could give T. pseudonana a competitive advantage over native species, but this has not been specifically researched.

There is little or no evidence to support that Thalassiosira pseudonana has significant socio-economic impacts in the Great Lakes.

There is little or no evidence to support that Thalassiosira pseudonana beneficial effect in the Great Lakes.
Realized:
Thalassiosira pseudonana was found to be useful for mariculture because it has a high fatty-acid composition (Volkman et al. 1989). Thalassiosira pseudonana is also used as a model organism for silica biomineralization because its entire gene sequenced has been published. Biomineralizaton is a growing field that is using diatoms to accelerate silica formation and form macromolecular assemblies that might act as structure-directing templates (Sumper and Brunner 2008).


Management:  

Regulations (pertaining to the Great Lakes region)
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: In 1958, Guillard isolated three diatom clones from an estuarine habitat (3-H), slope water (7-15), and open ocean (13-1). These clones were considered for years to be different forms of T. pseudonana. However, it turns out that clone 7-15 is identical to T. guillardii from brackish water and clone 13-1 is another species. Only clone 3-H is still considered to be T. pseudonana (Hasle 1982).


References (click for full reference list)


Other Resources:
Author: Kipp, R.M., M. McCarthy, and A. Fusaro


Contributing Agencies:
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Revision Date: 9/12/2019


Citation for this information:
Kipp, R.M., M. McCarthy, and A. Fusaro, 2024, Thalassiosira pseudonana (Hustedt) Hasle and Heimdal, (1957) 1970: 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=1692&Potential=N&Type=0&HUCNumber=DGreatLakes, Revision Date: 9/12/2019, Access Date: 5/2/2024

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.