Ecology of sound communication in fishes.

Friedrich Ladich

doi:10.1111/faf.12368

Abstract

Fishes communicate acoustically under ecological constraints which may modify or hinder signal transmission and detection and may also be risky. This makes it important to know if and to what degree fishes can modify acoustic signalling when key ecological factors—predation pressure, noise and ambient temperature—vary. This paper reviews short‐time effects of the first two factors; the third has been reviewed recently (Ladich, 2018). Numerous studies have investigated the effects of predators on fish behaviour, but only a few report changes in calling activity when hearing predator calls as demonstrated when fish responded to played‐back dolphin sounds. Furthermore, swimming sounds of schooling fish may affect predators. Our knowledge on adaptations to natural changes in ambient noise, for example caused by wind or migration between quiet and noisier habitats, is limited. Hearing abilities decrease when ambient noise levels increase (termed masking), in particular in taxa possessing enhanced hearing abilities. High natural and anthropogenic noise regimes, for example vessel noise, alter calling activity in the field and laboratory. Increases in sound pressure levels (Lombard effect) and altered temporal call patterns were also observed, but no switches to higher sound frequencies. In summary, effects of predator calls and noise on sound communication are described in fishes, yet sparsely in contrast to songbirds or whales. Major gaps in our knowledge on potential negative effects of noise on acoustic communication call for more detailed investigation because fishes are keystone species in many aquatic habitats and constitute a major source of protein for humans.

Highlights

The ability to communicate effectively with other individuals plays a major role in the lives of all animals
Numerous studies have investigated the effects of predators on fish behaviour, but only a few report changes in calling activity when hearing predator calls as demonstrated when fish responded to played-b ack dolphin sounds
Effects of predator calls and noise on sound communication are described in fishes, yet sparsely in contrast to songbirds or whales

Summary

| INTRODUCTION

The ability to communicate effectively with other individuals plays a major role in the lives of all animals. An ever increasing number of auditory studies emphasize the importance of sound detection in bony fishes (Putland, Montgomery, & Radford, 2018; Sisneros, 2016). Despite this wealth of information on sonic organs, sounds and hearing abilities, our knowledge about the ecology of sound communication is very limited. This paper reviews available empirical data regarding short-time effects on sound communication in fishes when predators are detected acoustically and when background noise varies. In order to reduce the predation threat, communicating animals should be able to react to the presence of predators by modifying their signalling behaviour. The cichlids preferred low-intensity behaviours such as lateral display and tail beating

40 Control Reef noise

Findings

| SUMMARY AND FUTURE RESEARCH