University of Alaska Anchorage
TRACKING CHANGES: POSTNATAL BLOOD AND MUSCLE OXYGEN STORE DEVELOPMENT IN HARBOR SEALS (PHOCA VITULINA)
Harbor seals (Phoca vitulina) are one of the most precocial phocids. They enter the water soon after birth and follow their mothers throughout the lactation period. This study examined the development of total body oxygen stores in pups as an index of aerobic dive ability, by measuring hematocrit, hemoglobin, red blood cell count, plasma volume, blood volume, muscle myoglobin concentration, and serum erythropoietin levels. From these values, blood and muscle oxygen stores were calculated and aerobic dive limit estimated. Results showed that blood and muscle develop at different rates and blood oxygen stores followed a two-stage developmental path. Early declines in circulating blood oxygen levels were associated with rapid mass gain, and stimulated erythropoietin production, which in turn stimulated red blood cell production and expansion of blood oxygen stores. Overall, pup dive behavior did not appear to be restricted by tissue oxygen stores despite smaller mass-specific oxygen stores than adults.
|Last update 10/27/09|