Browsing by Author "Munday, Philip L."
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- Behavioural lateralization and shoaling cohesion of fish larvae altered under ocean acidificationPublication . Lopes, Ana Filipa; Morais, Pedro; Pimentel, Marta S,; Rosa, Rui; Munday, Philip L.; Gonçalves, Emanuel João; Faria, Ana MargaridaRecent studies have shown that the behaviour and development of coral reef fish larvae is hampered by projected future CO2 levels. However, it is uncertain to what extent this effect also occurs in temperate species. The effects that elevated pCO2 (~2000 μatm) levels, which are expected to occur in coastal upwelling regions in the future, have on shoaling behaviour and lateralization (turning preference) of fish, were tested in temperate sand smelt Atherina presbyter larvae. The hypothesis that behavioural changes are caused by interference of high CO2 with GABA-A receptor function was tested by treating larvae with a receptor antagonist (gabazine). Routine swimming speed did not differ between control and high pCO2, but exposure to high pCO2 for 7 days affected group cohesion, which presented a more random distribution when compared to control fish. However, this random distribution was reversed after 21 days of exposure to high CO2 conditions. Lateralization at the individual level decreased in fish exposed to high pCO2 for 7 and 21 days, but gabazine reversed this decline. This adds to the growing body of evidence that the effects of a more acidified environment on fish larvae behaviour are likely due to altered function of GABA-A receptors. Overall, our results suggest that future pCO2 levels likely to occur in temperate coastal ecosystems could have an adverse effect on temperate larval fish behaviour.
- Painted Goby Larvae under high-CO2 fail to recognize reef soundsPublication . Castro, Joana M.; Amorim, Maria Clara Pessoa; Oliveira, Ana P.; Gonçalves, Emanuel João; Munday, Philip L.; Simpson, Stephen D.; Faria, Ana MargaridaAtmospheric CO2 levels have been increasing at an unprecedented rate due to anthropogenic activity. Consequently, ocean pCO2 is increasing and pH decreasing, affecting marine life, including fish. For many coastal marine fishes, selection of the adult habitat occurs at the end of the pelagic larval phase. Fish larvae use a range of sensory cues, including sound, for locating settlement habitat. This study tested the effect of elevated CO2 on the ability of settlement-stage temperate fish to use auditory cues from adult coastal reef habitats. Wild late larval stages of painted goby (Pomatoschistus pictus) were exposed to control pCO2 (532 μatm, pH 8.06) and high pCO2 (1503 μatm, pH 7.66) conditions, likely to occur in nearshore regions subjected to upwelling events by the end of the century, and tested in an auditory choice chamber for their preference or avoidance to nighttime reef recordings. Fish reared in control pCO2 conditions discriminated reef soundscapes and were attracted by reef recordings. This behaviour changed in fish reared in the high CO2 conditions, with settlement-stage larvae strongly avoiding reef recordings. This study provides evidence that ocean acidification might affect the auditory responses of larval stages of temperate reef fish species, with potentially significant impacts on their survival.