Body condition impacts blood and muscle oxygen storage capacity of free-living beluga whales (Delphinapterus leucas).

摘要: ABSTRACT Arctic marine ecosystems are currently undergoing rapid environmental changes. Over the past 20 years, individual growth rates of beluga whales ( Delphinapterus leucas ) have declined, which may be a response to climate change; however, scarcity physiological data makes it difficult gauge adaptive capacity and resilience species. We explored relationships between body condition parameters pertaining oxygen (O 2 storage in 77 eastern Beaufort Sea. Muscle myoglobin concentrations averaged 77.9 mg g −1 , one highest values reported among mammals. Importantly, blood haematocrit, haemoglobin muscle correlated positively indices condition, including maximum half-girth length ratios. Thus, whale with lowest index would ∼27% lower (26.0 versus 35.7 ml kg 12% (15.6 17.7 ml kg O stores than equivalent mass index; conservative assumption that underwater consumption unaffected by this equates >3 min difference maximal aerobic dive time two extremes (14.3 17.4 min). Consequently, changes negatively impact hinder ability reach preferred prey sources, evade predators escape ice entrapments. The relationship represent vicious cycle, resulting decreased impair foraging, leading further reductions through diminished acquisition and/or increased foraging efforts.