Nitokra hibernica
(Brady, 1880)
Common Name:
A harpacticoid copepod
Synonyms and Other Names:
Nitocra hibernica, Canthocamptus hibernicus
Identification:
This copepod exhibits a narrow rostrum and caudal rami that are two times longer than wide. The anal operculum generally displays 10 teeth along the edge. The 1st endopod segment is equal to or longer than the whole exopod. On the 3rd exopod segment of legs 2–4 there are 5, 5, and 7 spines, respectively (Lesko et al. 2003).
Size:
Female N. hibernica are around 0.5–0.75 mm long and males are around 0.5–0.6 mm long (Lesko et al. 2003).
Native Range:
Nitokra hibernica is native to Eurasia where it has a broad distribution. It occurs in such places as the Black and Caspian Seas; European coasts of the Atlantic, Arctic, and Baltic Seas; inland waters in south, east, and central Europe; and in central Asia and the Caucasus (Grigorovich et al. 2001; Lesko et al. 2003).
Great Lakes Nonindigenous Occurrences:
Nitokra hibernica was recorded for the first time from the mouth of the Niagara River on Lake Ontario in1972 and subsequently in southwestern Lake Ontario in 1973. It has also been recorded from Lake Michigan, Lake Erie, and Lake Huron. It should be noted that it was recorded in southern Lake Michigan in 2001 but it was not present in 2002 (Czaika 1978; Hudson et al. 1998; Lesko et al. 2003; Garza and Whitman 2004). In 2017, N. hibernica was collected from ballast water being discharged into Western Lake Superior at densities as high as 5 individuals/m3 (Cangelosi et al. 2018).
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 Nitokra hibernica are found here.
Full list of USGS occurrences
Table last updated 4/19/2024
† Populations may not be currently present.
Ecology:
Nitokra hibernica is a benthic invertebrate that occurs in fresh, brackish, coastal, and estuarine waters, exhibiting a broad salinity tolerance. It is usually associated with macrophyte beds and can be found in nearshore zones of large rivers and lakes. In the Great Lakes, most records are from nearshore areas, though a few have been from deeper regions. It has been recorded from Yankee Reef and Saginaw Bay, Lake Huron. In England it sometimes occurs at intakes and outflows of power stations (Markowski 1959; Zankai and Ponyi 1986; Gaviria 1998; Hudson et al. 1998; Grigorovich et al. 2001; Lesko et al. 2003; Duggan et al. 2005). Sexually mature female N. hibernica can carry 17–21 eggs in one egg sac (Lesko et al. 2003).
Means of Introduction:
Nitokra hibernica was probably introduced in ballast water in ships entering the Great Lakes (Duggan et al. 2005). Ballast exchange regulations for international vessels entering the Great Lakes are highly efficient at preventing introduction of international nonindigenous species (NIS), but Briski et al. have noted that a lack of ballast regulations in domestic shipping within the Great Lakes poses a threat to further spread of NIS between lakes (2012). Specifically, they sampled N. hibernica from ballast water destined for discharge in Lake Superior, where it has not yet been documented. They suggest domestic regulations be based on ecological boundaries rather than geographic and political borders to help prevent spread of NIS within the Great Lakes (Briski et al. 2012).
Status:
Established where recorded.
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 Nitokra hibernica in the Great Lakes is inadequate to support proper assessment. Realized:
The introductions of N. hibernica and its nonindigenous congener N. incerta are very likely responsible for the introduction of the suctorian ciliate Acineta nitocrae to Lake Erie (by N. hibernica) and the Detroit River (by N. incerta). Acineta nitocrae is known to be epizooic on these two copepods in the Ukraine (Grigorovich et al. 2001).
There is little or no evidence to support that Nitokra hibernica has significant socio-economic impacts in the Great Lakes.
There is little or no evidence to support that Nitokra hibernica has significant beneficial effects in the Great Lakes.
Potential:
Nitokra hibernica has been collected from the stomach of one slimy sculpin (Cottus cognatus) in Lake Huron, and rainbow smelt (Osmerus mordax) has been known to feed on it in Saginaw Bay, Lake Huron (Hudson et al. 1998, Lesko et al. 2003).
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
Nitokra hibernica has been found in the stomach of slimy sculpin (Cottus cognatus) at Yankee Reef, Lake Huron, and it is known to be consumed by rainbow smelt (Osmerus mordax) in Lake Huron, but the significance of this predation on biological control is unknown (Lesko et al. 2003).
Physical
There are no known physical control methods for this species.
Chemical
The Great Lakes and Mississippi River Interbasin Study (GLMRIS 2012) suggests that alteration of water quality using carbon dioxide, ozone, nitrogen, and/or sodium thiosulfate could be effective in preventing upstream and downstream movement of copepods. It should be noted that the effectiveness of these methods is likely significantly diminished against copepod ephippia.
Note: Check state/provincial and local regulations for the most up-to-date information regarding permits for control methods. Follow all label instructions.
Remarks:
Nitokra hibernica is synonymous with Canthocamptus hibernicus. Nitokra is frequently misspelled as Nitocra.
References
(click for full reference list)
Author:
Kipp, R.M., A.J. Benson, J. Larson, T.H. Makled, and A. Fusaro
Contributing Agencies:
Revision Date:
9/12/2019
Citation for this information:
Kipp, R.M., A.J. Benson, J. Larson, T.H. Makled, and A. Fusaro, 2024, Nitokra hibernica (Brady, 1880): 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=2372&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.