Foraging behaviour of the epaulette shark Hemiscyllium ocellatum is not affected by elevated CO2

• Main Authors: Heinrich, Dennis D U, Watson, Sue-Ann, Rummer, Jodie L, Brandl, Simon J, Simpfendorfer, Colin A, Heupel, Michelle R, Munday, Philip L
• Format: Dataset
• Language: English
• Published: PANGAEA 2016
• Subjects: Activity; standard deviation; Activity description; Alkalinity; total; Animalia; Aragonite saturation state; Behaviour; Benthos; Bicarbonate ion; Calcite saturation state; Calculated using CO2SYS; Calculated using seacarb after Nisumaa et al. (2010); Carbon; inorganic; dissolved; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Chordata; Coast and continental shelf; Containers and aquaria (20-1000 L or < 1 m**2); Figure; Fish; standard length; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Growth/Morphology; Hemiscyllium ocellatum; Identification; Laboratory experiment; Nekton; OA-ICC; Ocean Acidification International Coordination Centre; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); pH; Potentiometric; Potentiometric titration; Salinity; Single species; South Pacific; Species; Temperature; water; Time; Time in seconds; Treatment; Tropical; Ocean acidification
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.848868; https://doi.org/10.1594/PANGAEA.848868

Increased oceanic uptake of atmospheric carbon dioxide (CO2) is a threat to marine organisms and ecosystems. Among the most dramatic consequences predicted to date are behavioural impairments in marine fish which appear to be caused by the interference of elevated CO2 with a key neurotransmitter receptor in the brain. In this study, we tested the effects of elevated CO2 on the foraging and shelter-seeking behaviours of the reef-dwelling epaulette shark, Hemiscyllium ocellatum. Juvenile sharks were exposed for 30 d to control CO2 (400 µatm) and two elevated CO2 treatments (615 and 910 µatm), consistent with medium- and high-end projections for ocean pCO2 by 2100. Contrary to the effects observed in teleosts and in some other sharks, behaviour of the epaulette shark was unaffected by elevated CO2. A potential explanation is the remarkable adaptation of H. ocellatum to low environmental oxygen conditions (hypoxia) and diel fluctuations in CO2 encountered in their shallow reef habitat. This ability translates into behavioural tolerance of near-future ocean acidification, suggesting that behavioural tolerance and subsequent adaptation to projected future CO2 levels might be possible in some other fish, if adaptation can keep pace with the rate of rising CO2 levels.