Meeting Abstract

45.2  Monday, Jan. 5 10:45  Ocean Acidification and Arm Regeneration in the Burrowing Brittle Star Ophiophragmus filograneus CLEMENTS, LAJ*; STALKER, JC; WENK, L; Jacksonville University, Jacksonville, FL; Jacksonville University, Jacksonville, FL; Jacksonville University, Jacksonville, FL lclemen@ju.edu

Environmental perturbations, both natural and man-made have consequences on the growth, behavior and ecology of marine organisms. Ocean acidification is a consequence of elevated atmospheric CO₂ and may impact the calcification and growth of shallow sub-tidal benthic invertebrates. This experiment shows the effect of two levels of increased CO₂ on the regeneration of brittle star limbs. Three CO₂ levels (control, elevated and high) resulted in pH differences in aquaria-based treatments: control CO₂ pH ~8, elevated CO₂ pH ~7.5, and high CO₂ pH ~7. These pH levels reflect those reported by IPCC estimates. Ten brittle stars, each with one arm surgically removed, were placed in each of nine aquaria in a Latin square design. Temperature, salinity, pH levels, dissolved oxygen, and CO₂ pressure were monitored daily and animals were fed every third day. After one month, the dry weight and ash free dry weight of regenerated and non-regenerated portions of each individual were determined. Increased acidity and CO₂ levels resulted in increased in arm regeneration and a decrease in overall body mass. Ophiophragmus filograneus are able to utilize the additional CO₂ despite the decrease in pH, but there appears to be a metabolic cost which decreases overall body mass.