ALBERT

Description: The influence of elevated seawater pCO2 on statolith calcification and prey capture was investigated in the early life stages of the common cuttlefish, Sepia officinalis. Cuttlefish were reared at 15�C and 35 psu in a flow-through seawater system under three pCO2 conditions, 700 matm (control), 1400 matm, and 4000 matm during 63 days in June to August 2009. Both, embryonic and hatchling cuttlefish raised under 4000 matm showed significantly reduced statolith calcification, whereas those grown under control and 1400 matm did not. Reduced calcification was demonstrated by comparing 18 transects characterizing the anterior surface of the statoliths. The statolith morphometrics that showed the most remarkable changes between the different pCO2 conditions were total statolith length, rostrum transects, wing area and statolith weight. Statolith microstructure was significantly affected by irregularly arranged statoconia, which were typical in the statolith wing area, replacing the highly compact and well-arranged crystals in normal growing statoliths. This abnormal crystal structure can have profound effects on statolith density and consequently on its normal functioning as a tool for buoyancy, acceleration and movement. Changes in statolith morphology and microstructure may influence the prey capture efficiency of the early life cuttlefish. At 4000 matm they showed a reduced ability to capture prey and were not able to successfully launch attacks against prey organisms. In order to verify these observations, a second experiment was conducted over 85 days in May to August 2010. Preliminary results showed that statolith morphology and microstructure differed again in the 4000 matm group. On the other hand, prey capture ability of the hatchlings showed recovery during the experiment, indicating a possible acclimation.

Description: The influence of elevated seawater pCO2 on statolith calcification and prey capture was investigated in the early life stages of the common cuttlefish, Sepia officinalis. Cuttlefish were reared at 15�C and 35 psu in a flow-through seawater system under three pCO2 conditions, 700 matm (control), 1400 matm, and 4000 matm during 63 days in June to August 2009. Both, embryonic and hatchling cuttlefish raised under 4000 matm showed significantly reduced statolith calcification, whereas those grown under control and 1400 matm did not. Reduced calcification was demonstrated by comparing 18 transects characterizing the anterior surface of the statoliths. The statolith morphometrics that showed the most remarkable changes between the different pCO2 conditions were total statolith length, rostrum transects, wing area and statolith weight. Statolith microstructure was significantly affected by irregularly arranged statoconia, which were typical in the statolith wing area, replacing the highly compact and well-arranged crystals in normal growing statoliths. This abnormal crystal structure can have profound effects on statolith density and consequently on its normal functioning as a tool for buoyancy, acceleration and movement. Changes in statolith morphology and microstructure may influence the prey capture efficiency of the early life cuttlefish. At 4000 matm they showed a reduced ability to capture prey and were not able to successfully launch attacks against prey organisms. In order to verify these observations, a second experiment was conducted over 85 days in May to August 2010. Preliminary results showed that statolith morphology and microstructure differed again in the 4000 matm group. On the other hand, prey capture ability of the hatchlings showed recovery during the experiment, indicating a possible acclimation.