Figure 1 Identification Round gobies are bottom-dwelling fish that perch on rocks and other substrate. In flowing water habitats, this suction disk aids in anchoring the fish to the substrate. Round gobies look similar to sculpins, a native, bottom-dwelling fish occasionally caught by anglers. Both sculpins and goby males can appear almost solid black during spawning. Figure 2 Characteristics and Habitat Round gobies possess four characteristics that make them effective invaders.
Round gobies are aggressive, pugnacious fish.
They feed voraciously and may eat the eggs and fry of native fish such as sculpins, darters, and logperch. They will aggressively defend spawning sites in rocky habitats, thereby restricting access of native species to prime spawning areas. They have a well-developed sensory system that enhances their ability to detect water movement. This allows them to feed in complete darkness, and gives them a major competitive advantage over native fish in the same habitat. They are robust and are able to survive under degraded water quality conditions.