Active habitat selection by pre‐settlement reef fishes

Abstract

Our understanding of habitat selection by reef fish larvae has changed dramatically in the last 10 years. Fish larvae have long been considered passive particles at the mercy of ocean currents, tides and weather events. For reef fishes, ecological evidence has shown that passive dispersal alone often cannot explain larval distributions, suggesting active behaviour by reef fish larvae. While behaviourally modified passive transport may be important, recent work demonstrates that some reef fish larvae have the capability to actively swim to settlement habitat. They can orientate to reefs from distances of at least 1 km and can swim at speeds of 13.5 cm s−1 for several days. The question then becomes, what are the cues that fish larvae use to orientate to reefs? Ambient reef sound has been shown to be attractive to reef fish larvae, and current research aims to understand better the nature and use of these acoustic cues. Other potential cues include chemoreception/olfaction, wave cues and visual location of reefs. A better understanding of active habitat selection and the underlying sensory and behavioural mechanisms will improve our knowledge of recruitment processes in reef fish ecology, and may have implications for active management of reef fish populations.

Detection and quantification of marine larvae orientation in the pelagic environment

“…These methods have shown that fish larvae orient and that cues such as sound and chemical plumes originating from reefs can be detected and might be used for navigation. These findings were consistent among the studies and were the subject of recent reviews (e.g., Montgomery et al 2001Montgomery et al , 2006Kingsford et al 2002;Leis 2006). However, the scope of these results is limited due to methodological constraints, as detailed below.…”

“…However, fish are known to develop swimming capacities early (Leis 2006); hence, orientation of young individuals is potentially influential to the connectivity between adult populations. The behavior of younger larvae in the pelagic environment is still completely unknown and may involve other cues, such as magnetic or electric fields, sun position, swell, and waves (Montgomery et al 2001). Current methods are not appropriate to tackle these questions.…”

Patterns of Juvenile Habitat Use and Seasonality of Settlement by Permit, Trachinotus falcatus

“…The presence of settlement-size permit in windward beach samples and the lack of similar-size individuals in other habitats suggest that permit are actively settling along beaches. Such active settlement should not be surprising since larvae can use olfaction and sound to select settlement habitats (reviewed in Montgomery et al 2001). Although such cues were not examined in this study, if observed juvenile abundance patterns resulted from non-selective settlement and habitatspecific differential post-settlement mortality, one would expect capture of settlement-size individuals in other habitats.…”

Genetic structure and historical demography of the shanny Lipophrys pholis in the Portuguese coast based on mitochondrial DNA analysis

“…Fish larvae have long been considered passive particles at the mercy of ocean currents, tides, and weather events (Montgomery et al, 2001). For reef Wshes, ecological evidence has demonstrated that passive dispersal alone cannot explain larval distributions (e.g., Leis and Carson-Ewart, 1998).…”