Long-term effects of contrasting pCO2 levels on the scope for growth in the carnivorous gastropod Concholepas concholepas. (March 2022) - Navarro, J.M.
Abstract: We evaluated the effect of contrasting p CO2 levels: lower (390 μatm), moderate (700 μatm) and extreme (1000 μatm), on the scope for growth of the keystone snail Concholepas concholepas over an exposure period of 6 months. Juvenile snails were collected from rocky intertidal habitats and acclimated for 5 months to those p CO2 levels. Subsequently, three groups of snails were randomly taken (n = 7 for each treatment) and reared for an additional 1 month for each of the three p CO2 levels. Physiological traits related with energy gain and energy expenditure were quantified. The scope for growth index decreased significantly with increases in p CO 2, yielding negative values throughout the experimental period for the snails exposed to 1000 μatm p CO 2, probably due to the extra energy required to maintain their metabolic functions in balance. This suggests that future climate change scenarios with elevated p CO2 levels could threaten the growth and other basic functions of juvenile snails of this species. Highlights: Exposure time has a significant effect on most of the physiological responses Scope for growth index decreased significantly with increases in p CO 2 High p CO2 levels threat the growth and impact negatively snails' fitness