Fanning behaviour and communication in the round goby (Neogobius melanostomus), an invasive fish

Determination of reproductive status in male round gobies can be challenging and the specifics of communication between males and females prior to spawning are unknown. First, I observed male fanning behaviour and compared this to both morphological and physiological measurements to determine if fanning is related to condition or reproductive status. My findings suggest that fins may be a useful measure of reproductive status and that fanning behaviour may be an important aspect of courtship potentially revealing parental abilities. I subsequently examined female responses to changes in flow in the presence of reproductive and juvenile male conditioned water using a y-maze flume experiment. My findings revealed that reproductive females prefer low flow conditions and reproductive conditioned water, whereas non-reproductive females prefer the opposite. This research represents the first investigation into the possible role of displacement fanning in this species and whether females may be using flow when evaluating potential mates.