Many vertebrates are known to show behavioural lateralization, whereby they differentially use one side of their body or either of their bilateral organs or limbs. Behavioural lateralization often manifests in a turning bias in fishes, with some individuals showing a left bias and others a right bias. Such biases could be the source of considerable conflict in fish schools given that there may be considerable social pressure to conform to the group to maintain effective group evasion. Here, we show that predation pressure is a major determinant of the degree of lateralization, both in a relative and absolute sense, in yellow-and-blueback fusiliers (Caesio teres), a schooling fish common on coral reefs. Wild-caught fish showed a bias for right turning. When predation pressure was experimentally elevated or relaxed, the strength of lateralization changed. Higher predation pressure resulted in an increase in the strength of lateralization. Individuals that exhibited the same turning bias as the majority of individuals in their group had improved escape performance compared with individuals that were at odds with the group. Moreover, individuals that were right-biased had improved escape performance, compared with left-biased ones. Plasticity in lateralization might be an important evolutionary consequence of the way gregarious species respond to predators owing to the probable costs associated with this behaviour.

The bigmouth buffalo (Ictiobus cyprinellus) is an iconic freshwater fish native to North America that is in decline. Recent studies have revealed bigmouth buffalo exhibit a slow pace of life, yet demographic information on bigmouth buffalo outside of North Dakota and Minnesota is lacking. We used otoliths to investigate population demographics of bigmouth buffalo in Canada, and also monitored bigmouth buffalo spawning frequency and reproductive success in the wild. From a sample of 52 fish collected during 2018 – 2021 we found bigmouth buffalo from the Qu’Appelle system more than 125 years old. Only 13 year classes ranging from 1894 – 1997 were evident with only one year class since 1948, indicating recruitment has been episodic. During the past decade (2013 – 2022) bigmouth buffalo have spawned only once (May of 2013) in Buffalo Pound Lake. This spawning effort culminated in recruitment failure because the water-level recession rate was too rapid. Our findings indicate that bigmouth buffalo spawning attempts as well as recruitment occur within a narrow range of water-level fluctuations that may rarely occur, which is enabled by their supercentenarian lifespan, and has direct implications for the conservation of this species.

Many species possess damage‐released chemical alarm cues that function in alerting nearby individuals to a predator attack. One hypothesis for the evolution and/or maintenance of such cues is the Predator Attraction Hypothesis, where predators, rather than prey, are the “intended” recipients of these cues. If a predator attack attracts additional predators, these secondary predators might interfere with the predation event, providing the prey with a better chance to escape. In this study, we conducted two experiments to explore this hypothesis in an amphibian predator/prey system. In Experiment 1, we found that tiger salamanders (Ambystoma mavortium) showed a foraging attraction to chemical cues from wood frog (Lithobates sylvaticus) tadpoles. Salamanders that were experienced with tadpole prey, in particular, were strongly attracted to tadpole alarm cues. In Experiment 2, we observed experimental encounters between a tadpole and either one or two salamanders. The presence of the second predator caused salamanders to increase attack speed at the cost of decreased attack accuracy (i.e., increasing the probability that the tadpole would escape attacks). We also found that the mere presence of visual and chemical cues from a second predator did not affect this speed/accuracy trade‐off but did cause enough of a distraction to increase tadpole survival. Thus, our findings are consistent with the Predator Attraction Hypothesis for the evolution and/or maintenance of alarm cues.

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