title: Ocean acidification boosts larval fish development but reduces the window of opportunity for successful settlement.
abstract: Locating appropriate settlement habitat is a crucial step in the life cycle of most benthic marine animals. In marine fish, this step involves the use of multiple senses, including audition, olfaction and vision. To date, most investigations of larval fish audition focus on the hearing thresholds to various frequencies of sounds without testing an ecological response to such sounds. Identifying responses to biologically relevant sounds at the development stage in which orientation is most relevant is fundamental. We tested for the existence of ontogenetic windows of reception to sounds that could act as orientation cues with a focus on vulnerability to alteration by human impacts. Here we show that larvae of a catadromous fish species (barramundi, Lates calcarifer) were attracted towards sounds from settlement habitat during a surprisingly short ontogenetic window of approximately 3 days. Yet, this auditory preference was reversed in larvae reared under end-of-century levels of elevated CO2, such that larvae are repelled from cues of settlement habitat. These future conditions also reduced the swimming speeds and heightened the anxiety levels of barramundi. Unexpectedly, an acceleration of development and onset of metamorphosis caused by elevated CO2 were not accompanied by the earlier onset of attraction towards habitat sounds. This mismatch between ontogenetic development and the timing of orientation behaviour may reduce the ability of larvae to locate habitat or lead to settlement in unsuitable habitats. The misinterpretation of key orientation cues can have implications for population replenishment, which are only exacerbated when ontogenetic development decouples from the specific behaviours required for location of settlement habitats.
authors.affiliation: Southern Seas Ecology Laboratories, School of Biological Sciences and The Environment Institute, The University of Adelaide, DX 650 418, Adelaide, South Australia 5005, Australia.
authors.forename: Tullio
authors.initials: T
authors.lastname: Rossi
authors.affiliation: Southern Seas Ecology Laboratories, School of Biological Sciences and The Environment Institute, The University of Adelaide, DX 650 418, Adelaide, South Australia 5005, Australia ivan.nagelkerken@adelaide.edu.au.
authors.forename: Ivan
authors.initials: I
authors.lastname: Nagelkerken
authors.affiliation: Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD, UK.
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Simpson
authors.affiliation: Southern Seas Ecology Laboratories, School of Biological Sciences and The Environment Institute, The University of Adelaide, DX 650 418, Adelaide, South Australia 5005, Australia.
authors.forename: Jennifer C A
authors.identifier: 0000-0001-8081-7069
authors.initials: JC
authors.lastname: Pistevos
authors.affiliation: Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia.
authors.forename: Sue-Ann
authors.initials: SA
authors.lastname: Watson
authors.affiliation: AgroParisTech, Paris Institute of Technology for Life, Food and Environmental Sciences, 16 rue Claude Bernard, Cedex 5, Paris 75231, France.
authors.forename: Laurene
authors.initials: L
authors.lastname: Merillet
authors.affiliation: Southern Seas Ecology Laboratories, School of Biological Sciences and The Environment Institute, The University of Adelaide, DX 650 418, Adelaide, South Australia 5005, Australia.
authors.forename: Peter
authors.initials: P
authors.lastname: Fraser
authors.affiliation: Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia.
authors.forename: Philip L
authors.initials: PL
authors.lastname: Munday
authors.affiliation: Southern Seas Ecology Laboratories, School of Biological Sciences and The Environment Institute, The University of Adelaide, DX 650 418, Adelaide, South Australia 5005, Australia.
authors.forename: Sean D
authors.initials: SD
authors.lastname: Connell
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D002245:Carbon Dioxide / Q000032:analysis; D003463:Cues; D017753:Ecosystem; D006309:Hearing; D006863:Hydrogen-Ion Concentration; D007814:Larva / Q000254:growth & development / Q000502:physiology; D008675:Metamorphosis, Biological; D009792:Oceans and Seas; D009949:Orientation / Q000502:physiology; D010473:Perciformes / Q000254:growth & development / Q000502:physiology*; D012623:Seawater / Q000737:chemistry*; D013016:Sound
chemical_list: D002245:Carbon Dioxide
keywords: audition; behaviour; mangrove; ontogeny; orientation; soundscape