INDEXES OF BODY CONDITION AND BODY-COMPOSITION IN FEMALE ANTARCTIC FUR SEALS (ARCTOCEPHALUS-GAZELLA)

An attempt was made to develop simple, inexpensive, rapid means of det ermining body composition in Antarctic fur seals (Arctocephalus gazell a). Measurements of total body water (TBW) and total body lipid (TBL), obtained by hydrogen isotope dilution, were compared to the results o f bioelectrical impedance analysis (BIA) and morphometric indices of b ody condition in 52 adult females. TBW was weakly correlated with BIA measurements of resistance (r = -0.30, P < 0.03). Conductor volume (le ngth(2)/resistance) was more highly correlated with TBW(r = 0.75, P < 0.0001) and the inclusion of mass into the predictive equation improve d the correlation further (r = 0.95, P < 0.0001). A body condition ind ex (mass/length) previously used in pinniped studies was positively co rrelated to TBL (r = 0.77, P < 0.0001) validating its use as a relativ e index of condition. However, body mass alone was highly correlated t o TBW (r = 0.94, P < 0.0001) and appears to provide a simple, rapid me ans of estimating body composition in adult females. This technique ma y also be applicable to juvenile male Antarctic fur seals.