Skeletonema subsalsum
(Cleve-Euler) Bethge, (1912) 1928
Common Name:
A centric diatom
Synonyms and Other Names:
Melosira subsalsa Cleve-Euler 1912
Identification:
Cells of this diatom species are cylindrical, contain one chloroplast, and form chains. Valve surfaces are flat to somewhat rounded. There are fultoportulae (hollow tubular processes) in a ring around the edges, perpendicular to the valve face, that connect to the next cells’ processes. The number of marginal processes and their length are positively related to salinity. Areolae (pores) are frequently rectangular, especially on the mantle, and arranged in a radial pattern on the valves. There are typically 3–4 areolae between each process (Hasle and Evensen 1975, 1976, Paasche et al. 1975, Sarno et al. 2005).Valve diameter of S. subsalsum can vary from 2.6–10.3 μm and may be positively related to salinity (Hasle and Evensen 1975, Genkal and Kuzmin 1980, Sarno et al. 2005).
Size:
Diameter <11 microns
Native Range:
Skeletonema subsalsum is native to Eurasian water bodies including the Baltic Sea, the Caspian Sea, northern Germany, Sweden, Finland, and the Sea of Azov (Hasle and Evensen 1975, Mills et al. 1993, Sarno et al. 2005).
|
|
|
This map only depicts Great Lakes introductions.
|
|
Great Lakes Nonindigenous Occurrences:
Skeletonema subsalsum was first recorded in 1973 in Lake Erie and subsequently recorded in Lake Ontario, Lake Huron, and Lake Michigan (Hasle and Evensen 1976, Mills et al. 1993, Stoermer 1978).
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 Skeletonema subsalsum are found here.
Table last updated 4/19/2024
† 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:
Skeltonema subsalsum is a fresh to brackish water species, usually occurring in salinities up to 15‰ in rivers, lakes, inland seas, coastal waters, and marshes, and often associated with eutrophic conditions (Clarke 1995, Gibson et al. 2003, Hasle and Evensen 1975, Mills et al. 1993). Skeletonema subsalsum has been recorded in temperate regions in spring, summer, and fall. It has been recorded in the Great Lakes in the spring and in the St. Lawrence estuary in the summer. It is particularly known to occur during periods of elevated water temperature in the Great Lakes (Cardinal and Berard-Therriault 1976, Gibson et al. 1993, Reuter 1979, Stoermer 1978). In the Gulf of Mexico, S. subsalsum has been recorded during the rainy season from July to February (Castillo et al. 1995).
Means of Introduction:
Skeletonema subsalsum was very likely introduced to the Great Lakes drainage in ships’ 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...
There is little or no evidence to support that Skeletonema subsalsum has significant environmental impacts in the Great Lakes.
Potential:
Skeletonema subsalsum was recorded to be 17.6% of the biomass in the spring diatom blooms in Lake Erie. These blooms were dominated by native taxa and there was no indication that S. subsalsum was out-competing native species (Reuter 1979). In its native range, S. subsalsum occurs in brackish waters. While it is able to grow and reproduce in freshwater, S. subsalsum does not undergo cell enlargement in freshwater as it does in brackish environments (Balzano et al. 2001).
There is little or no evidence to support that Skeletonema subsalsum has significant socio-economic impacts in the Great Lakes.
There is little or no evidence to support that Skeletonema subsalsum has significant beneficial effects in the Great Lakes.
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 the 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:
Skeletonema subsalsum has also been recorded from waters in Argentina (Devercelli 2006), Brazil (John 2002), and the Gulf of Mexico (Castillo et al. 1995).
References
(click for full reference list)
Author:
Kipp, R.M., M. McCarthy, and A. Fusaro
Contributing Agencies:
Revision Date:
9/12/2019
Citation for this information:
Kipp, R.M., M. McCarthy, and A. Fusaro, 2024, Skeletonema subsalsum (Cleve-Euler) Bethge, (1912) 1928: 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=2712&Potential=N&Type=0&HUCNumber=DHuron, Revision Date: 9/12/2019, Access Date: 4/19/2024
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.