Ve vodách České republiky se vyskytuje hlavačka poloměsíčitá (Proterorhinus semilunaris) od r. 1994 a hlaváč černoústý (Neogobius melanostomus) od r. 2008. Oba druhy se poměrně rychle naturalizovaly a postupně rozšířily v povodí dolní Dyje a Moravy. Hlaváč byl v r. 2015 zavlečen pravděpodobně lodní dopravou i do dolního úseku Labe u Ústí nad Labem. Předpokládaný negativní vliv hlaváčů na původní ryby se zatím nepotvrdil. Naopak se hlaváči stali vítanou kořistí většiny dravců. Zatímco sedimentace a růst vodních makrofyt na dolní Dyji v posledních letech početnost hlaváče, preferujícího čistý kamenný substrát, snižuje, početnost hlavačky naopak podporuje. V následujících letech se ukáže, jak se bude vztah hlaváčů a našich ryb vyvíjet.

Použitá a doporučená literatura:

JANÁČ, Michal, et al. Long-term monitoring of native bullhead and invasive gobiids in the Danubian rip-rap zone. Hydrobiologia, 2018, 807.1: 263-275.
KALOUS, Lukáš, et al. The danger in the anglers’ bucket: qualitative and quantitative insight into bait fish market in Prague (Czech Republic). Acta Soc Zool Bohem, 2013, 77: 27-35.
MIKL, Libor, et al. Invasive Ponto-Caspian gobies in the diet of piscivorous fish in a European lowland river. Fundamental and Applied Limnology/Archiv für Hydrobiologie, 2017, 190.2: 157-171.
ONDRÁČKOVÁ, Markéta, et al. Temporal effects on host-parasite associations in four naturalized goby species living in sympatry. Hydrobiologia, 2015, 746.1: 233-243.
ŠLAPANSKÝ, Luděk; JURAJDA, Pavel; JANÁČ, Michal. Early life stages of exotic gobiids as new hosts for unionid glochidia. Freshwater Biology, 2016, 61.6: 979-990.
ROCHE, K. F.; JANÁČ, M.; JURAJDA, P. A review of Gobiid expansion along the Danube-Rhine corridor–geopolitical change as a driver for invasion. Knowledge and Management of Aquatic Ecosystems, 2013, 411: 01.
VAŠEK, Mojmír, et al. Diet of two invading gobiid species (Proterorhinus semilunaris and Neogobius melanostomus) during the breeding and hatching season: no field evidence of extensive predation on fish eggs and fry. Limnologica-Ecology and Management of Inland Waters, 2014, 46: 31-36.

The Tubenose Goby (Proterorhinus semilunaris) and Round Goby (Neogobius melanostomus) have occurred in Czech waters since 1994 and 2008, respectively. Both species quickly became established and spread into the lower stretches of the Dyje and Morava Rivers. The Round Goby has also been introduced into the lower Elbe at Ústí nad Labem, probably by shipping. To date, though expected, no impacts on native fishes have been confirmed. On the other hand, gobies are now a favoured prey of many predators. While, an increase in sedimentation and aquatic vegetation in recent years reduced the spread of the round goby, which prefers clean stony substrates, it appears to support the establishment of another invader, the tubenose goby. Ongoing studies will determine how the relationship between invasive gobies and our own native fish will develop in the years to come.