aggressive
animal species
biodiversity
biological invasion
destruction
displace
ecosystems
fish
fisheries authority
fishing
freshwater fish
gobies
gobiidae
goby
habitats
hand
hands
harmless
inconspicuous
introduced
invasion
native
neogobius melanostomus
overfishing
plague
pollution
pugnacious fish
river
rivers
round gobies
round goby
small
species
species extinction
wildlife conservation
young fish