Gammarus tigrinus
Sexton 1939
Common Name:
Tiger scud
Synonyms and Other Names:
Tigermärle (SE); Gefleckter Flussflohkrebs, Getigerter Bachflohkrebs (DE); Kielz tygrys (PL); Leväkatka (FI); Tijgervlokreeft (NL) [translates as tiger scud]
Identification:
Amphipods in the family Gammaridae have accessory flagellae on their 1st antennae and also display well-developed third uropods (biramous appendages on the posterior abdomen). Mature male G. tigrinus typically have relatively long and curly 2nd antennae, distinct setae on their pereopods (walking legs), and 2-5 groups of posterior marginal setae on the 2nd peduncular (basal) segment of their 1st antennae. Females have fewer setae on the antennae and pereopods (Bousfield 1969; Grigorovich et al. 2005). See Bousfield (1969) for a detailed description.
Size:
Length varies greatly with temperature, salinity, and type of food. In Saginaw Bay, Lake Huron, males average 10.5 mm and females average 7.6 mm in length (Grigorovich et al. 2005).
Native Range:
This species is native to the Atlantic coast of North America.
Great Lakes Nonindigenous Occurrences:
Gammarus tigrinus was first discovered in Saginaw Bay, Lake Huron, in 2002. Archived material indicates that this species was present in Lake Superior and Lake Erie in 2001. Subsequent collections revealed that it is present in all of the Great Lakes (Grigorovich et al. 2005; Kelly et al. 2006). This species has expanded its range outside the Great Lakes. It has been found in the lower Ohio River on the OH/KY border and further upriver on the OH/WV border, as well as in the upper Mississippi River near the confluence of the Ohio River and upriver to a location on the Wisconsin-Minnesota border (Grigorovich et al. 2008).
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 Gammarus tigrinus are found here.
Full list of USGS occurrences
Table last updated 4/23/2024
† Populations may not be currently present.
Ecology:
This euryhaline species tolerates salinities from 0–25‰, pH 6–10, relatively eutrophic conditions, hypoxic habitats, and warmer temperatures (mortality occurs at 32–34°C) in saltier water than other gammarid species (Bousfield 1969; Barlocher and Porter 1986; Winn and Knott 1992; MacNeil et al. 2003; Wijnhoven et al. 2003; Grigorovich et al. 2005). Gammarus tigrinus prefers rivers and shallow lakes in turbid, low salinity habitats, but can colonize lower depths (to approximately 20 m) if displaced by competitors from preferred littoral habitat (Dodson et al. 1989; MacNeil et al. 2003; Grigorovich et al. 2005). In Lake Huron, it mostly occurs in very shallow areas on silty sand, on Cladophora, or in macrophyte beds (Grigorovich et al. 2005). Densities in Lake Huron average 280 m-2 while those in some European habitats can reach 103 m-2 (Chambers 1977; Grigorovich et al. 2005; Wawrzyniak-Wydrowska and Gruszka 2005).
Gammarus tigrinus is omnivorous. It filter feeds suspended organic matter and can also directly consume zooplankton, plants, algae, detritus, and even its own young (Hunte and Myers 1984; Grigorovich et al. 2005).
Reproducing adults occur in freshwater in the Great Lakes. In Saginaw Bay, reproductive females carry 32 embryos on average and populations contain many more juveniles and females than males, probably because males have shorter life spans (Grigorovich et al. 2005). Gammarus tigrinus often matures in a few months, reproduces quickly, and produces 3-16 generations annually (Chambers 1977; Grigorovich et al. 2005). Reproduction can be triggered at any time of year if ambient 10°C temperature increases by 15–16°C (Ginn et al. 1976).
Means of Introduction:
Very likely introduced in ballast water (Grigorovich et al. 2005). Populations of G. tigrinus in the Great Lakes are genetically similar to those from the Hudson River estuary (Kelly et al. 2006).
Status:
Not established yet, may be introduced (U.S. EPA 2008).
Great Lakes Impacts:
Current research on the environmental impact of Gammarus tigrinus in the Great Lakes is inadequate to support proper assessment. Realized:
In many wetland habitats along the Great Lakes’ perimeter, G. tigrinus is the second most abundant amphipod after G. pseudolimnaeus (Grigorovich et al. 2005).
Potential:
There is a potential for G. tigrinus to exert negative impacts on the native Great Lakes amphipod community resulting from predation and competition (Dick 1996, Grigorovich et al. 2005).
Gammarus tigrinus has colonized European waters extensively, spreading along the Baltic Sea coast at rates of around 40 km/year and covering a total of approximately 1000 km from 1975 to 1998 (Grigorovich et al. 2005). As a facultative carnivore of other macroinvertebrates, G. tigrinus is thought to influence community structure (e.g., trophic relationships) through niche preemption of resources that would normally be consumed by its prey (Savage 2000). The central European invasion of G. tigrinus has been accompanied by elimination of some native amphipod species from parts of the Rhine River, the Baltic Sea, and several waterbodies in the Netherlands. It is frequently a superior predator compared to native amphipods and could possibly have a reproductive advantage over such indigenous species as G. duebeni, G. zaddachi, and G. pulex (Grigorovich et al. 2005, Pinkster et al. 1977). Increased mortality in the Baltic Sea native amphipod, G. salinus, has been attributed to increased competition with G. tigrinus over Pilayella littoralis, a mutually-grazed macrophyte species (Orav-Kotta et al. 2009). Furthermore, although G. tigrinus appeared to be a favored prey item of threespine stickleback (Gasterosteus aculeatus) in the Baltic Sea, the presence of G. tigrinus also facilitated fish predation on G. salinus in certain habitat types (Kotta et al. 2010).
Gammarus tigrinus coexists in Ireland with the native opossum shrimp Mysis relicta and there is mutual predation (Bailey et al. 2006). However, the mysid has been forced to change its use of microhabitat, exposing itself to increased fish predation due to the presence of G. trigrinus (Bailey et al. 2006). Gammarus tigrinus also preys on relatively small North American amphipod, Crangonyx pseudogracilis, in Ireland and could similarly prey on it in the Great Lakes (Dick 1996, Grigorovich et al. 2005). However, while G. tigrinus can exclude C. pseudogracilis from habitats with good water quality, in poor water quality habitats, this may not be the case (MacNeil et al. 2001).
This species can act as an intermediate host to the acanthocephalan Paratenuisentis ambiguus, whose definitive host is the American eel (Anguilla rostrata) (Samuel and Bullock 1981).
There is little or no evidence to support that Gammarus tigrinus has significant socio-economic impacts in the Great Lakes.
Potential:
Quickly following its introduction to rivers in Germany and the Netherlands, reports emerged of extreme cases in which heavy densities of G. tigrinus had adverse effects on fishing gear and trapped fish (Pinkster et al. 1977).
There is little or no evidence to support that Gammarus tigrinus has significant beneficial effects in the Great Lakes.
Potential:
Great Lakes fish likely consume G. tigrinus but this has yet to be studied (H. MacIsaac, pers. comm.; but see list of Gammarus spp. fish predators in MacNeil et al. 1999).
Management:
Regulations
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
Gammarus tigrinus can tolerate maximum water temperatures between 32.2°C and 34.2°C before irreversible physiological damage and mortality occur (Wijnhoven et al. 2003). In a study of the effects of tide gate operation on hypoxic conditions in the Back River and Savannah River estuaries in Savannah, Georgia, it was found that oxygen saturation levels below 30% are lethal to experimental populations of amphipods, and that Gammarus tigrinus is especially susceptible to low dissolved oxygen levels, exhibiting mortality within 3 hours of exposure to levels between 12 and 18% (Winn and Knott 1992).
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 the Netherlands, the Ponto-Caspian amphipod Dikerogammarus villosus is eliminating G. tigrinus, a previously successful invader in this region (Dick and Platvoet 2000).
References
(click for full reference list)
Author:
Kipp, R.M, J. Larson, A. Fusaro,T. Makled, and A. Benson
Contributing Agencies:
Revision Date:
9/12/2019
Citation for this information:
Kipp, R.M, J. Larson, A. Fusaro,T. Makled, and A. Benson, 2024, Gammarus tigrinus Sexton 1939: 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=2650&Potential=N&Type=0&HUCNumber=DHuron, Revision Date: 9/12/2019, Access Date: 4/23/2024
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.