ABSTRACT
The decline in ocean water pH and changes in carbonate saturation states through anthropogenically mediated increases in atmospheric CO2 levels may pose a hazard to marine organisms. This may be particularly acute for those species reliant on calcareous structures like shells and exoskeletons. This is of particular concern in the case of valuable commercially exploited species such as the king scallop, Pecten maximus. In this study we investigated the effects on oxygen consumption, clearance rates and cellular turnover in juvenile P. maximus following 3 months laboratory exposure to four pCO2 treatments (290, 380, 750 and 1140 µatm). None of the exposure levels were found to have significant effect on the clearance rates, respiration rates, condition index or cellular turnover (RNA: DNA) of individuals. While it is clear that some life stages of marine bivalves appear susceptible to future levels of ocean acidification, particularly under food limiting conditions, the results from this study suggest that where food is in abundance, bivalves like juvenile P. maximus may display a tolerance to limited changes in seawater chemistry.
Subject(s)
Animal Feed , Pecten/metabolism , Seawater/chemistry , Animals , Carbon Dioxide/pharmacology , DNA/metabolism , Energy Metabolism/drug effects , Hydrogen-Ion Concentration , Intracellular Space/drug effects , Intracellular Space/metabolism , Pecten/cytology , Pecten/drug effects , Pecten/growth & development , RNA/metabolism , Time FactorsABSTRACT
On the ventral surface of all scorpions are jointed appendages called pectines, which possess thousands of sensory sensilla. Researchers have electrophysiologically examined these peg sensilla in the past, providing evidence for their chemosensitivity and intra-peg synaptic interactions. However, limits to extracellular recording and chemical stimulation have impeded further research. In this study, we develop and apply a new tip-recording technique for stimulating and recording peg neurons. Relative to previous methods in pecten electrophysiology, this technique allows for very fast and efficient data assembly. Using it, we captured sensilla chemoresponses to aqueous stimulants. We see utility in this method for advancing our understanding of sensory physiology; specifically, we suggest this technique may be useful for physiological assays on scorpion and other arthropod chemoreceptors, such as insect and crustacean gustatory sensilla.
