Resting metabolic rate and heat increment of feeding in juvenile South American fur seals (Arctocephalus australis)

DASSIS, MARIELA; RODRÍGUEZ, DIEGO; IENO, ELENA; DENUNCIO, PABLO; LOUREIRO, JULIO; DAVIS, RANDALL WILLIAMS

COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-MOLECULAR AND INTEGRATIVE PHYSIOLOGY

ELSEVIER SCIENCE INC

Lugar: Amsterdam; Año: 2014 vol. 168 p. 63 - 68

1095-6433

Bio-energetic models used to characterize an animal?s energy budget require the accurate 19 estimate of different variables such as the resting metabolic rate (RMR) and the heat increment 20 of feeding (HIF). In this study, we estimated the in air RMR of wild juvenile South American fur 21 seals (SAFS; Arctocephalus australis) temporarily held in captivity by measuring oxygen 22 consumption while at rest in a postabsorptive condition. HIF, which is an increase in metabolic 23 rate associated with digestion, assimilation and nutrient interconversion, was estimated as the 24 difference in resting metabolic rate between the postabsorptive condition and the first 3.5 hours 25 postprandial. As data were hierarchically structured, linear mixed effect models were used to 26 compare RMR measures under both physiological conditions. Results indicated a significant 27 increase (61%) for the postprandial RMR compared to the postabsorptive condition, estimated at 28 17.93 ± 1.84 and 11.15 ± 1.91 ml O2 min-1 kg-1, respectively. These values constitute the first 29 estimation of RMR and HIF in this species, and should be considered in the energy budgets for 30 juvenile SAFS foraging at-sea.