The scaling of total parasite biomass with host body mass

Poulin, R.; George-Nascimento, M

Abstract

The selective pressure exerted by parasites on their hosts will to a large extent be influenced by the abundance or biomass of parasites supported by the hosts. Predicting how much parasite biomass can be supported by host individuals or populations should be straightforward: ultimately, parasite biomass must be controlled by resource supply, which is a direct function of host metabolism. Using comparative data sets on the biomass of metazoan parasites in vertebrate hosts, we determined how parasite biomass scales with host body mass. If the rate at which host resources are converted into parasite biomass is the same as that at which host resources are channelled toward host growth, then on a log-log plot parasite biomass should increase with host mass with a slope of 0.75 when corrected for operating temperature. Average parasite biomass per host scaled with host body mass at a lower rate than expected (across 131 vertebrate species, slope = 0.54); this was true independently of phylogenetic influences and also within the major vertebrate groups separately. Since most host individuals in a population harbour a parasite load well below that allowed by their metabolic rate, because of the stochastic nature of infection, it is maximum parasite biomass, and not average biomass, that is predicted to scale with metabolic rate among host species. We found that maximum parasite biomass scaled isometrically (i.e., slope = 1) with host body mass. Thus, larger host species can potentially support the same parasite biomass per gram of host tissues as small host species. The relationship found between maximum parasite biomass and host body mass, with its slope greater than 0.75, suggests that parasites are not like host tissues: they are able to appropriate more host resources than expected from metabolically derived host growth rates. © 2006 Australian Society for Parasitology Inc.

Más información

Título según WOS: The scaling of total parasite biomass with host body mass
Título según SCOPUS: The scaling of total parasite biomass with host body mass
Título de la Revista: INTERNATIONAL JOURNAL FOR PARASITOLOGY
Volumen: 37
Número: 03-abr
Editorial: ELSEVIER SCI LTD
Fecha de publicación: 2007
Página de inicio: 359
Página final: 364
Idioma: English
URL: http://linkinghub.elsevier.com/retrieve/pii/S0020751906004000
DOI:

10.1016/j.ijpara.2006.11.009

Notas: ISI, SCOPUS