Response of naïve two-spotted gobies Gobiusculus flavescens to visual and chemical stimuli of their natural predator, cod Gadus morhua

Abstract

In order to determine whether the anti-predator response of gobies to cod Gadus morhua is inherited, naïve two-spotted gobies Gobiusculus flavescens were exposed to visual or chemical cod stimuli, in order to determine whether such stimuli would trigger an innate anti-predator response. Groups of 10 naïve adult two-spotted gobies were tested for their distribution between 2 habitats in an aquarium: 1 'safe' and 1 'risky' habitat, in which a cod was presented either visually or by its odour. Equal amounts of food were available in the 2 habitats. When no predator stimuli were presented in either habitat, the gobies distributed themselves equally between them both. When a visual stimulus of a cod was presented in 1 of the habitats, they avoided this habitat. The introduction of cod odour in 1 of the habitats did not influence the distribution of the gobies. After a single session with a cod physically present in 1 habitat, the gobies still did not respond to the introduction of cod odour the following day. However, after having experienced a cod being physically present on 3 consecutive feeding sessions, they responded to cod odour with avoidance. The response to cod odour was still significant 6 mo after the experience. It therefore appears that the goby has an innate fear of any larger fish, while the recognition of a specific predator odour has to be learned. KEY WORDS: Innate response · Olfactory predator cue · Visual predator cue · Gobiusculus flavescens · Gadus morhuaResale or republication not permitted without written consent of the publisher

Swordtail Fry Attend to Chemical and Visual Cues in Detecting Predators and Conspecifics

“…Second, It has been argued that prey animals' responses to the presence of predators is under strong selection to be a highly generalized and stereotypical response – though in some cases requiring experiential learning to become stereotypical. This argument is supported by the common usage of single individuals as predator stimuli in previous studies of predator avoidance behavior in fishes [7], [9], [24]. For these reasons, we did not find it necessary to conduct replicated trials using multiple cichlids as predator stimuli.…”

“…This hypothesis has received much support among studies of adult fish [7], [8], [21; reviewed in refs. 22], [23], and in a handful of studies investigating the use of predator chemical cues by juvenile fish.…”

“…25], [26]. Third, in species where experience is important in predator avoidance – such as in two-spotted gobies [7] – an inexperienced individual may benefit by associating with more experienced individuals who have acquired important predator avoidance behaviors.…”

“…Vulnerability to predators may be particularly high for young fish due to their small size and lack of experience with predators. In two-spotted gobies ( Gobiusculus flavescens ), for instance, whether juveniles respond to predator chemical stimuli depends on prior visual experience with the predator [7]; [see also ref. 8].…”

Learned Defences and Counterdefences in Predator–Prey Interactions

“…Utne-Palm (2001) found that naïve two-spotted gobies (Gobiusculus flavescens, Gobiidae) subsequently avoided the habitat where they last saw a live cod predator (Gadus morhua, Gadidae), but avoided cod odour only after observing cod on three successive occasions. Brown ) similarly found that rainbowfish (Melanotaenia spp., Melanotaeniidae) avoided habitats where they had previously encountered a model of their natural predator, the mouth almighty (Glossamia aprion, Apogonidae).…”