Babka goby, Sand goby, River goby, Gobius fluviatilis Pallas, 1814, Gobius sordidus Bennet, 1835, Gobius steveni Nordmann, 1840, Gobius fluviatilis nigra Kessler, 1859

Nonindigenous Occurrences: Neogobius fluviatilis is found in the Yantra River, Bulgaria (Vassilev et al. 2008). This species occurs in the Rhine River in Germany (Borcherding et al. 2013). Neogobius fluviatilis was caught in Lake Balaton in 1970 (Biró 1972) and was also documented in Sió Channel, Tisza River, and Bodrog River in Hungary (Ahnelt et al. 1998). In 2009, Neogobius fluviatilis was recorded in the Waal, Rijn, and Boven Merwede rivers in the Dutch Rhine, and the Meuse River in Netherlands (van Kessel et al. 2009, 2011). It was recorded in the Austrian portion of the Danube River (Szaloky et al. 2015). This species was introduced to Polish inland waters during the mid-1990s and has spread to the southern Baltic Sea (Lejk et al. 2013) and occurs in the Vistula basin, Poland (Timm et al. 2009). It was introduced in Serbia in 1977 (Lenhardt et al. 2010). Neogobius fluviatilis is found in reservoirs of the Volga River and the Kuybyshev and Saratov Reservoirs in Russia (Mineeva et al. 2020).  It was documented in the Danube River in Slovakia (Jurajda et al. 2005). Neogobius fluviatilis was introduced to parts of the Aral Sea in the mid-1950s and currently occurs there (Plotnikov et al. 2012).  It is also found in the Sava River basin, Croatia (Piria et al. 2011).

Potential pathway(s) of introduction: Transoceanic shipping (ballast water)

Neogobius fluviatilis is predicted to be introduced to the Great Lakes via ballast water (Ricciardi and Rasmussen 1998; Kolar and Lodge 2002; Holeck et al. 2004). Neogobius fluviatilis is euryhaline and can tolerate a broad range of temperature, so it may be able to survive ballast tank environments. It has been found in waters with temperatures of 0–32.4°C (Biró 1997; Sasi and Berber 2010), and salinities between 0-46 ppt (Plotnikov et al. 2012; Lejk et al. 2013; Snyder et al. 2014). This species occurs in waters from which shipping traffic to the Great Lakes originates (NBIC 2009), including the Baltic Sea (Lejk et al. 2013). Neogobius fluviatilis occurs in the River Vistula catchment, which is part of the Baltic Sea basin (Copp et al. 2005). Neogobius fluviatilis may be introduced to the Great Lakes via ships declaring “No Ballast on Board” (NOBOB), which are exempt from ballast water exchange. Holeck et al. (2004) specifically states this introduction will be through BOB water or NOBOB residual water. The majority of ships entering the Great Lakes are NOBOB vessels and 43% of these ships contain residual water with less than 10‰ salinity (NOAA Final Report 2005). In the study, the temperature of the residual water from the vessels sampled ranged from -0.7 to 23.9°C; thus Neogobius fluviatilis is likely to survive the salinity and temperature of the NOBOB ballast water.

Neogobius fluviatilis does not occur near waters connected to the Great Lakes basin. This species is not known to adhere to any surfaces or be transported by other organisms. Neogobius fluviatilis is not stocked, cultured, or sold in the Great Lakes region.

Neogobius fluviatilis has a high probability of establishment if introduced to the Great Lakes (Confidence level: High).

The native and introduced ranges of Neogobius fluviatilis have similar climatic and abiotic conditions as the Great Lakes (Reid and Orlova 2002; Grigorovich et al. 2003; US EPA 2008). Genetic Algorithm for Rule-Set Production (GARP) model predicts that shallower waters of the Great Lakes provide suitable habitats for Neogobius fluviatilis, including parts of Lake Huron, Lake Michigan, Lake Erie, and Lake Ontario (US EPA 2008). Top et al. (2019) speculate that habitats with sandy substrate are potentially more vulnerable to N. fluviatilis invasion due to their plasticity in habitat use. There is adequate sandy substrate in the Great Lakes that could be vulnerable to such an invasion. Neogobius fluviatilis has a broad temperature tolerance; it inhabits waters that freeze in the winter (Biró 1997), as well as waters with temperatures up to 32.40°C (Sasi and Berber 2010). Neogobius fluviatilis can tolerate fresh to brackish waters with salinities of 0–10 ppt (Plotnikov et al. 2012; Lejk et al. 2013). Neogobius fluviatilis occurs in waters that have ice cover in the winter, such as Lake Balaton (Biró 1997), so it is likely capable of overwintering in the Great Lakes. Lake Balaton’s water quality was impacted by eutrophication in the 1960s, yet this species was able to establish there in the early 1970s; thus nutrient levels of the Great Lakes will not likely affect the establishment of Neogobius fluviatilis. Due to its tolerance of a wide range of water temperatures and salinity, the effects of climate change in the Great Lakes may promote the establishment of Neogobius fluviatilis. Gobies in invaded habitats typically have a lower abundance and diversity of parasites than in their native range (Molnar 2006; Kvach et al. 2014), which can increase their invasion success (Torchin et al. 2003).

This species has a diverse diet of macroinvertebrates, crustaceans, gastropods, and fish (Grabowska et al. 2009); thus it is likely to find an appropriate food source in the Great Lakes basin. Neogobius fluviatilis reduced energy expenditures when starved in an overwintering scenario (5°C water for 90 days), resulting in high survival rates (Fortes Silva et al. 2019).  In laboratory experiments investigating habitat competition between native and invasive species, Neogobius fluviatilis did not significantly alter the habitat use of the native species Cottus perifretum, C. gobio, or Barbatula barbatula (van Kessel et al. 2011; Blonska et al. 2016). Depending on the size of the female, fecundity ranges from 300-10,600 mature oocytes (Pinchuk et al. 2003; Gertzen et al. 2016). Newly established populations of Neogobius fluviatilis may allocate more resources to reproduction, and live longer than N. fluviatilis populations in their native range (Plachá et al. 2010). It exhibits parental care and has an extended spawning period, which may contribute to reproductive success.

Kolar and Lodge (2002) predict that Neogobius fluviatilis will spread quickly if introduced to the Great Lakes. In the last 3 decades of the 20th century, this species was among 4 Ponto-Caspian gobies that expanded their range up the Volga River (Copp et al. 2005). This species is capable of upstream migration, and has expanded its range from the Djerdap Gorge in Serbia to the middle sections of the Danube River in Slovakia (Jurajda et al. 2005). The invasion history of Neogobius fluviatilis is characterized by range expansions occurring from Eastern towards Western Europe. Within 7 years, it spread 836 km downstream from the Bug River to the mouth of the Vistula River (Kostrzewa and Grabowski 2002). After its introduction to the Aral Sea in the mid-1950s, Neogobius fluviatilis naturalized and its abundance grew quickly (Plotnikov et al. 2012). By the mid-1960s, increased densities of Neogobius fluviatilis as well as other undesirable introduced goby species coincided with a significant reduction in the abundance of benthic invertebrates (Markova et al. 1972; Yablonskaya et al. 1973; Plotnikov et al. 2012); however, it is unknown if Neogobius fluviatilis was responsible for the decline of benthic invertebrates. Neogobius fluviatilis has continued to expand into the Sava River basin in Croatia, and was the dominant gobiidae species in the region likely due to its propensity for upstream migration (Jakovlic et al. 2015). It is expected to continue expanding throughout central Europe and into the entire Nemunas River drainage system (Rakauskas et al. 2018).

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

Environmental	Socioeconomic

Neogobius fluviatilis is known to be the carrier of some species of parasites, and, it had the greatest parasite diversity and the lowest parasite abundance compared to 2 other non-native goby species found in the Danube River (Ondracková et al. 2005). None of the parasites were brought to the Danube by the introduction of Neogobius fishes; rather, they were common in the Danube. The parasite loads in Neogobius fluviatilis in the Danube River were similar to the fish’s parasite loads in its native range. Parasites of Neogobius fluviatilis in the Danube River include trematoda Nicolla skrjabini (Iwanitzky, 1928), Metagonimus yokogawai (Katsurada, 1912), Apatemon cobitidis (Linstow, 1980), Pomphorhynchus laevis (Müller, 1776), Raphidascaris acus (Bloch, 1779), ciliophora Ichthyophthirius multifiliis (Fouquet, 1876), Eimeria daviesae (Molnár 2000), and Goussia kessleri (Molnár 2000; Molnár 2006). Specimens of Neogobius fluviatilis in the Vistula River were infected with the metacercariae of Bucephalus polymorphus, a parasite that also infects zebra mussels (Kvach and Mierzejewska 2011). The effects of the parasites infecting Neogobius fluviatilis on zebra mussels have not been reported. Gobies including Neogobius fluviatilis are reported to co-introduce the parasite Gyrodactylus proterohini, however, this parasite is unlikely to infect non-gobiid hosts (Ondracková 2016). Neogobius fluviatilis is also host to the microsporidian Loma acerinae which also infects Atherinids including Atherina boyeri (Ovcharenko et al. 2017). A full list of parasites for N. fluviatilis in both their native and non-native ranges can be found in Kvach and Ondracková (2020).

Where introduced, Neogobius fluviatilis may potentially impact native fish populations. A marked decline in tubenose goby in the Danube River was attributed to the rapid expansion of round goby and monkey goby populations in 2004 (Molnár 2006). Experiments investigating habitat competition between non-native and native fish of the Rhine and Meuse rivers did not find that native fish Cottus perifretum or Barbatula barbatula changed their selection of habitat type when they co-occurred with Neogobius fluviatilis. These experiments suggest that Neogobius fluviatilis does not compete with native benthic fish for habitat, but its competitive behavior may change during spawning season (van Kessel et al. 2011). Further, in experimental trials, Neogobius fluviatilis did not impact shelter use by European bullhead (Cottus gobio) (Blonska et al. 2016).

Neogobius fluviatilis makes up a substantial proportion of the diets of piscivorous fish such as Sander lucioperca and S. volgensis in Lake Balaton (Specziár 2011). The effects of non-native prey on the diets of S. lucioperca and S. volgensis or on predator-prey relationships has not been explored. The expansion of Neogobius fluviatilis as well as other undesirable introduced goby species coincided with a significant reduction in the abundance of benthic invertebrates (Markova et al. 1972; Yablonskaya et al. 1973); however, it is unknown if Neogobius fluviatilis was responsible for the decline of benthic invertebrates. Neogobius fluviatilis may also be responsible for the decline of whitefin gudgeon (Romonaogobio vladykovi) in the River Zagyva, Hungary due to food competition and predation (Harka and Szepesi 2017). In addition, N. fluviatilis nearly extirpated the Carpathian gudgeon (Gobio carpathicus) in only two years after their invasion in the Eger river, Hungary (Szepesi et al. 2019).  In the Rhine river, N. fluviatilis exhibited greater competitive ability for food than juvenile native fishes (Aspius aspius, Perca fluviatilis, and Sander lucioperca), resulting in a competitive bottleneck for native fishes before they developed enough to instead consume the gobies (Borcherding et al. 2019).

There is little or no evidence to support that Neogobius fluviatlis has the potential for significant socio-economic impacts if introduced to the Great Lakes.

It has not been reported that Neogobius fluviatilis poses a threat to human health or water quality. There is no evidence that this species negatively impacts infrastructure, economic sectors, recreational activities and associated tourism, or the aesthetic appeal of the areas it inhabits.

Neogobius fluviatilis has the potential for moderate beneficial impact if introduced to the Great Lakes.

In Turkey, Neogobius fluviatilis is important to minor commercial fisheries, aquarium dealers, and bait shop vendors (Sasi and Berber 2010). They may serve as a source of food for economically important fish species such as pike (Esox lucius), European catfish (Silurus glanis), pikeperch (Sander lucioperca), and were heavily consumed (85.7% index of relative importance) by Eurasian perch (Perca fluviatilis)(Lenhardt et al. 2010; Didenko et al. 2016).

Similar to Neogobius melanostomus, N. fluviatilis may feed on dreissenid mussels, but the extent of this is unknown (Kipp et al. 2012).

There are no known regulations for this species.*

*Ballast water regulations applicable to this species are currently in place to prevent the introduction of nonindigenous species to the Great Lakes via shipping. See Title 33: Code of Federal Regulations, Part 151, Subparts C and D (33 CFR 151 C) for the most recent federal ballast water regulations applying to the Great Lakes and Hudson River.

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. Kolar and Lodge (2002) recommend avoid transporting bottom dwelling monkey gobies in ballast water by drawing ballast water from the upper regions of the water column or treating ballast water during periods of peak larval goby abundance.

Chemical
There are no known chemical control methods specific to this species. General piscicides (such as rotenone) may be used for control, but expect significant kill of non-target species.

Note: Check state/provincial and local regulations for the most up-to-date information regarding permits for control methods. Follow all label instructions.