Timoniella sp.
Common Name:
A digenean fluke, trematode
Synonyms and Other Names:
previously Acanthostomum
Identification:
See Brooks (2004) for a key to genera in the subfamily Acanthostominae. Note that Timoniella and Acanthostomum are treated as distinct genera in this key, but Acanthostomum is now considered to be a junior synonym of Timoniella.
Size:
microscopic
Native Range:
Unknown (possibly Eurasia).
|
|
|
This map only depicts Great Lakes introductions.
|
|
Great Lakes Nonindigenous Occurrences:
Timoniella sp. was first discovered in the Great Lakes in 1992 on Eurasian ruffe (Gymnocephalus cernua) in Lake Superior, Michigan (Pronin et al. 1997). In 1994, it was isolated again from Eurasian ruffe in Lake Superior at Allouez Bay and Pokegama Bay, Wisconsin (Pronin et al. 1998).
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 Timoniella sp. are found here.
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:
Metacercariae of Timoniella sp. occurred in densities of 7-61 per Ruffe and were found on the fins, mouth, and eyes of this fish in Lake Superior (Pronin et al. 1997). The tail of the cercarial stage of Timoniella gives it a strong swimming ability, allowing it to infect fishes away from the area in which the cercaria were shed (El-Darsh & Whitfield 1999). The invertebrates that serve as intermediate hosts of this species in the Great Lakes are unknown.
Means of Introduction:
Possibly introduced with Eurasian ruffe, Gymnocephalus cernuus (U. S. Department of the Interior 1993) or with Round gobies, Neogobius melanostomus (cf. Kvach & Skora 2007) in ballast water.
Status:
Presumed 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 Timoniella sp. has significant environmental impacts in the Great Lakes.
Timoniella sp. has only been isolated in the Great Lakes from the introduced Eurasian ruffe (G. cernua) (Pronin et al. 1997, 1998). As such, it is unlikely to exert negative impacts on native fish species. However, members of this trematode genus have been documented to parasitize additional fish species (e.g., Kvach and Skora 2006, Zander and Reimer 2002).
There is little or no evidence to support that Timoniella sp. has significant socio-economic impacts in the Great Lakes.
There is little or no evidence to support that Timoniella sp. has significant beneficial effects in the Great Lakes.
Timoniella sp. infection of the introduced Eurasian ruffe in the Great Lakes has ranged from densities of 7-61 parasites per ruffe, with up to 100% prevalence (Pronin et al. 1997, 1998). However, Timoniella sp. is believed to be unlikely to help regulate populations of the introduced Eurasian ruffe.
A relationship between resistance to anoxia in Eurasian ruffe and its parasite load has been observed, such that increased richness of parasites, including Timoniella sp., negatively affects the Ruffe's ability to survive low-oxygen conditions (Pronin et al. 1997). Furthermore, species of Timoniella have been documented to occur in gobies outside the Great Lakes (e.g. Kvach and Skora 2006, Malek 2003). It is not known how the presence of these parasites might affect non-native fish population dynamics and competitive interactions with native fishes in the Great Lakes.
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.
Controls
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 cryptogenic species is likely nonindigenous to the Great Lakes, as it has been found only on an introduced species – the Eurasian ruffe (U.S. Department of the Interior 1993). It has not been previously reported from North American freshwater fishes (Hoffman 1999). One species of Timoniella (T. imbutiforme) infests round gobies in their native range (Kvach & Skora 2007), suggesting the possibility that at least two exotic fish species may serve as hosts and may have played a role in the introduction of this parasite to the Great Lakes.
This species was previously known as Acanthostomum sp. but this name is now considered invalid.
References
(click for full reference list)
Author:
Kipp, R.M., A.K.Bogdanoff, A. Fusaro and R. Sturtevant.
Contributing Agencies:
Revision Date:
9/13/2019
Citation for this information:
Kipp, R.M., A.K.Bogdanoff, A. Fusaro and R. Sturtevant., 2024, Timoniella sp.: 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=2727&Potential=N&Type=0&HUCNumber=DGreatLakes, Revision Date: 9/13/2019, 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.