Some widely successful species, sometimes called “invasive”, outcompete by being versatile, such as having a broad diet. In being euryhaline – able to withstand wide-ranging salinity, the round goby is that. But what got the goby its widespread presence is an inner strength.
Small and soft-bodied, the round goby is a bottom-dweller native to central Eurasia, including the Black Sea and Caspian Sea. Thanks to furtive human transport, round gobies established large populations in several major Eurasian rivers and the Great Lakes of North America. “The invasive benthic round goby (Neogobius melanostomus) is the most successful temperate invasive fish and has spread in aquatic ecosystems on both sides of the Atlantic,” explains Swiss zoologist Irene Adrian-Kalchhauser.
Unlike other fish, round gobies are not especially bothered by polluted waters. “The round goby occurs in chemically contaminated harbors and appears to tolerate xenobiotic compounds well,” observes Adrian-Kalchhauser.
Beyond generalized adaptability, there is little especial about the round goby genetically. What keeps a goby going is its robust immune system. “While round goby adaptive immunity conforms to vertebrate standards, its innate immune repertoire displays remarkable and unusual features,” marvels Adrian-Kalchhauser. Simply put, the round goby is built tough.
Irene Adrian-Kalchhauser et al, “The round goby genome provides insights into mechanisms that may facilitate biological invasions,” BMC Biology (28 January 2020).
“Why the goby can conquer the waters of the world,” ScienceDaily (11 February 2020).
Round goby photo courtesy of Lubomir Hlasek.