Helo everyone
For the past decade or so, metabolic rate has been discussed as a determinant
of population density. The evidence has been the relationshis between body
size and abundance and between body size and metabolic rate; abundance scales
to body size with a slope of minus 0.75, and metabolic rate scales with a
slope of pluss 0.75 (on log-log scales). From this people have inferred that
population abundance is limited by energy availability, the mechanisms beeing
the metabolic rate. All evidence stems from free-living animals, mainly birds
and mammals.
Parasites have been thought not to be energy limited. But is this
true ? I have recently found a negative relationship between body size and
population density across nematodes parasitising mammals. The slope is not
far from minus 0.75. But what is the relationship between body size and
metabolic rate in mammalian nematodes (or helminth parasites in general) ? I
have been searching for estimates of species basal metabolic rate, but have
found only one in the litterature. Do any of you know of papers where the
metabolic rate of nematodes have been estimated ? Please do not hesitate to
send me an e-mail. Do anyone have opinions on whether parasites populations
may be energy limited ?
Cheers
Per Arneberg
Department of Ecology/Zoology
IBG, University of Tromsoe, Norway
e-mail: pera at ibg.uit.no
