. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 78 C. P. MANGUM AND J. S. RAINER and seaside crabs are responsible for the differences in Hc02 affinity. Because Hc02 affinity also changes with season (Mauro and Mangum, 1982), we performed our experiments during July—the same month in which pre- vious experiments were performed (Mason et ai, 1983). Materials and Methods We either captured or purchased crabs from local wa- termen whose pots had been placed at known locations. Water salinity was determined, by conductivity (Yellow Springs Instrument Co. Model 33 salinometer)
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 78 C. P. MANGUM AND J. S. RAINER and seaside crabs are responsible for the differences in Hc02 affinity. Because Hc02 affinity also changes with season (Mauro and Mangum, 1982), we performed our experiments during July—the same month in which pre- vious experiments were performed (Mason et ai, 1983). Materials and Methods We either captured or purchased crabs from local wa- termen whose pots had been placed at known locations. Water salinity was determined, by conductivity (Yellow Springs Instrument Co. Model 33 salinometer), in both cases. As in the previous investigation (Mason et ai, 1983), a transfer experiment was designed as paired observa- tions on the same individuals before and after a salinity change. Blood was taken from each individual before and after the transfer. We intended to save one aliquot for electrophoresis and use the other for 02 binding. Poor survival dictated otherwise and we used all of the mate- rial available to ascertain our earlier finding of a shift in Hc02 affinity. As an alternative to holding previously bled animals in the laboratory at the time of year when mortality is already great, we observed different phenotypes at the es- tuarine (York River) and seaside (Wachapreague) habi- tats. We first sampled large numbers of animals, then identified the phenotypes electrophoretically, and finally performed 02 binding measurements on them. Hc02 equilibrium measurements were made using the cell respiration method (Mangum and Lykkeboe, 1979). After clotting the samples were homogenized in a tissue grinder, centrifuged, and dialyzed overnight against a sa- line. Regression lines were fit to the data describing log P50 as a function of pH and the 95% confidence intervals around the lines and their slopes were compared for overlap. Values for P50 at a single pH and those for coop- erativity were analyzed according to Student's /-test. Hcs were dissociated by dialysis aga
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
