Special K: Testing the potassium link between radioactive rubidium (<sup>86</sup>Rb) turnover and metabolic rate
MetadataShow full item record
© 2014. Published by the Company of Biologists Ltd.The measurement of 86Rb turnover recently has been suggested as a useful method for measuring field metabolic rate in small animals. We investigated a proposed mechanism of 86Rb turnover, its analogy to K+, by comparing the turnover of 86Rb in a model insect, the rhinoceros beetle Xylotrupes gideon, fed a diet of plum jam or plum jam enriched with K+ or Rb+. The turnover of 86Rb in the beetles on the K+ and the Rb+ diets was higher than that for beetles on the jam diet (F2,311=32.4; P=1.58×10-13). We also exposed the beetles to different ambient temperatures to induce differences in metabolic rate (VCO2) while feeding them the jam and K+ diets. VCO2 was higher at higher ambient temperature (Ta) for both jam (F1,11=14.56; P=0.003) and K+ (F1,8=15.39; P=0.004) dietary groups, and the turnover of 86Rb was higher at higher Tafor both jam (F1,11=10.80; P=0.007) and K+ (F1,8=12.34; P=0.008) dietary groups. There was a significant relationship between 86Rb turnover and VCO2 for both the jam (F1,11=35.00; P=1.0×10-3) and the K+ (F1,8=64.33; P=4.3×10-5) diets, but the relationship differed between the diets (F1,19=14.07; P=0.001), with a higher 86Rb turnover in beetles on the K+-enriched than on the jam diet at all Ta. We conclude that 86Rb turnover is related to K+ metabolism, and that this is the mechanism of the relationship between 86Rb turnover and VCO2. Studies relating 86Rb turnover to VCO2 should maintain dietary [K+] as close as possible to that of natural diets for the most accurate calibrations for free-ranging animals.
Showing items related by title, author, creator and subject.
Oil mallee plantings and arthropod biodiversity in the Western Australian wheatbelt : effects of host species, nutrition, and leaf chemistryLyons, Anita Marie (2008)Since European settlement, around 93% of the Western Australian wheatbelt has been cleared for agriculture, leading to a range of environmental problems, including erosion, salinity, and loss of biodiversity. Recently, ...
Cummings, Nicola Kim (2006)There is substantial evidence from cellular, animal and epidemiological studies in support of a role for calcium, and in particular, dairy foods in the regulation of weight (McCarron, 1983; Davies et al. 2000; Heaney, ...
Energy and water use by invasive goats (Capra hircus) in an Australian rangeland, and a caution against using broad-scale allometry to predict species-specific requirementsCooper, Christine; Munn, A.; Russell, B.; Dawson, T.; McLeod, S.; Maloney, S. (2012)Feral goats (Capra hircus) are ubiquitous across much of Australia's arid and semi-arid rangelands, where they compete with domestic stock, contribute to grazing pressure on fragile ecosystems, and have been implicated ...