Meeting Abstract
P2.16 Friday, Jan. 4 Effect of Exposure to Bacteria on Metabolism during Exercise and Recovery in the Atlantic blue crab, Callinectes sapidus THIBODEAUX, L.**; BURNETT, K.; BURNETT, L.; Grice Marine Lab, College of Charleston ; Grice Marine Lab, College of Charleston ; Grice Marine Lab, College of Charleston lindy.thibodeaux@gmail.com
Previous studies have shown that exposure to bacteria reduces aerobic metabolism in resting blue crabs, while hemolymph lactate increases, suggesting an increase in anaerobic metabolism. We investigated how metabolism changes with activity (walking on a treadmill) in blue crabs and how this is influenced by exposure to bacteria. After 30 min of walking (8 m min-1) O2 uptake increased significantly from 4.59±0.37SEM to 11.59±0.86 µmol g-1h-1(N=7) and hemolymph lactate increased significantly from 0.39±0.04SEM to 1.00±0.87 mmol l-1(N=5). Both O2 uptake and hemolymph lactate returned to normal levels within 3 h after walking. Crabs injected with a sublethal dose of Vibrio campbellii (105 g-1) 1 h prior to 30 min of walking consumed significantly less O2 during exercise (7.94±0.82SEM µmol g-1h-1) than saline-injected crabs. This significant reduction in O2 uptake persisted during the entire 3 h recovery period. Vibrio-injected crabs also accumulated higher amounts of hemolymph lactate (3.63±0.67SEM mmol l-1) than saline controls during 30 min of exercise; this elevation persisted for 2 h after activity. As much as 50% of the difference in aerobic metabolism during walking could be accounted for by this significant increase in lactate production and accumulation in tissues of Vibrio-injected crabs; however, a small amount (0.25 µmol g-1h-1) of lactate also was excreted into the water. Whole body lactate, as well as muscle ATP, ADP, AMP and arginine phosphate during and after exercise, are being assessed currently. While both control and Vibrio-injected crabs are able to sustain the same level of activity, exposure to Vibrio clearly changes the pattern of energy consumption in blue crabs. Supported by NSF IBN-0212921.
