Behavioural responses to con- and heterospecific alarm cues by an alien and a coexisting native fish

Abstract

The monkey goby Neogobius fluviatilis is an invasive Ponto-Caspian fish that enters habitats of the native gudgeon Gobio gobio in European freshwaters, likely belonging to the same prey guild. Their abilities to detect and avoid predation have been poorly understood, although these traits may contribute to the competitive advantage and drive the invasion success of the goby. We tested intra- and interspecific responses of fish from sympatric populations to damage-released alarm cues (skin extract) in laboratory. Both species of fish responded to conspecific and heterospecific cues, but their responses to conspecifics were more diverse (changed social distancing among individuals, reduced vertical and horizontal movement) than those elicited by heterospecifics (changed social distancing only). Moreover, the fish differed in their anti-predation behaviour: the gudgeon increased whilst the monkey goby decreased inter-individual distances and only the gudgeon exhibited thigmotaxis and reduced mobility in response to the conspecific cues. Interspecific differences show that the species exhibit distant anti-predation strategies. This might be associated with their phylogenetic distance and/or higher differentiation of their ecological niches than commonly assumed. Besides, our results suggest that alien species be included in the interspecific exchange of information in local fish assemblages.

Differences in predator-avoidance behavior between two invasive gobies and their native competitors

“…The round goby is discriminated from the other goby species by a significantly deeper caudal peduncle, which may be associated with their better locomotion abilities ( Jakubčinová et al 2017 ) and, consequently, better ability to escape from attacks of predators. Nevertheless, the shorter, less pronounced, and less diverse defensive behavior we recorded in the invasive gobies is consistent with the study by Kłosiński et al (2022) , who showed that the monkey goby is generally less responsive to the damage-released chemical alarm cues compared to the gudgeon. Thus, our findings suggest that the significant share of the invasive gobies in the predator diet may be not only due to their high density ( Płąchocki et al 2012 ; Crane and Einhouse 2016 ; Mikl et al 2017 ), according to the optimal foraging theory ( Werner and Hall 1974 ; Pyke and Starr 2021 ), but also because of the weak behavioral defenses of invasive gobies against predators.…”

“…The authors pointed out that because of the characteristic body shape, which is not adapted to prolonged swimming, benthic fish, such as gobies, display a burst-and-hold swimming mode. In conjunction with the results of Kłosiński et al (2022) , showing the thigmotaxis and dispersion of the gudgeon in response to the alarm substance, this increased number of escapes suggests avoidance of the dangerous area as the main antipredator behavior of this species. Instead, the monkey goby seems to rely on activity reduction allowing it to avoid detection by predators ( Čápová et al 2008 ; Jakubčinová et al 2017 ).…”

“…High abundances of the gobies are recorded in colonized environments ( Kakareko et al 2009 , 2016 ), and so they are potentially widely available prey for predators. Nevertheless, in an experimental study on behavioral reactions to predation cues (prey skin extracts), the gudgeon exhibited thigmotaxis and reduction in horizontal and vertical mobility, while the monkey goby did not show any of those behaviors ( Kłosiński et al 2022 ). This suggests that weaker antipredator responses of invasive gobies may indeed contribute to their susceptibility to predation in invaded areas.…”

Risk Perception: Chemical Stimuli in Predator Detection and Feeding Behaviour of the Invasive Round Goby Neogobius melanostomus

“…Many previous studies have shown that the magnitude of reactions in fish increases with the concentration of cues—e.g., in goldfish Carassius auratus (Linnaeus, 1758) exposed to dietary cues from a predator [ 131 ]—where variations in concentrations may indicate different degrees of threat [ 132 ]. Moreover, it seems that the frequency of the application of the alarm substance might also influence outcomes if we compare our results to those from studies of the behavioural response of the monkey goby Neogobius fluviatilis (Pallas, 1814) [ 133 ]. Continuous dosing with damage-released alarm cues (skin extract) in these studies may have given more potent effects than in our experiment in which the extract was only applied every four hours.…”

The presence of predators constrains larval development process by influencing critical developmental windows in the endangered Chinhai spiny newt

“…The net cage allowed cues to be transmitted but did not allow predation. Previous studies have indicated that cues from both predators and preys could trigger predator‐induced response in prey (Anderson & Mathis, 2016; Kłosiński et al., 2022; Lucon‐Xiccato et al., 2018). Therefore, we assumed that this designed predator condition would create a predator threat through predator cues and prey alarm cues.…”