Data from: Ocean acidification boosts larval fish development but reduces the window of opportunity for successful settlement
Rossi, Tullio et al. (2015), Data from: Ocean acidification boosts larval fish development but reduces the window of opportunity for successful settlement, Dryad, Dataset, https://doi.org/10.5061/dryad.2cf6s
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 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 test for the existence of ontogenetic windows of reception to sounds that can 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) are attracted towards sounds from settlement habitat during a surprisingly short ontogenetic window of ~3 days. Yet, this auditory preference is 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 was 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 is only exacerbated when ontogenetic development decouples from the specific behaviours required for location of settlement habitats.