title: Parasite performance and host alternation: is there a negative effect in host-specific and host-opportunistic parasites?
abstract: Environmental fluctuations are expected to require special adaptations only if they are associated with a decrease in fitness. We compared reproductive performance between fleas fed on alternating (preferred and non-preferred) hosts and fleas fed solely on either a preferred or a non-preferred host to determine whether (1) host alternation incurs an immediate negative effect, and, if yes, then (2) whether this effect is greater in a host specialist (Parapulex chephrenis) than in host generalists (Xenopsylla conformis and Synosternus cleopatrae). We also compared flea performance under alternating host regimes with different host order (initial feeding on either a preferred or a non-preferred host). An immediate negative effect of alternating hosts on reproductive performance was found in P. chephrenis only. These fleas produced 44·3% less eggs that were 3·6% smaller when they fed on alternating hosts as compared with a preferred host. In contrast, X. conformis and S. cleopatrae appeared to be able to adapt their reproductive strategy to host alternation by producing higher quality offspring (on average, 3·1% faster development and 2·1% larger size) without compromising offspring number. However, the former produced eggs that were slightly, albeit significantly, smaller when it fed on alternating hosts as compared with a preferred host. Moreover, host order affected reproductive performance in host generalists (e.g. 2·8% larger eggs when the first feeding was performed on a non-preferred host), but not in a host specialist. We conclude that immediate effects of environmental fluctuation on parasite fitness depend on the degree of host specialization.
authors.affiliation: Mitrani Department of Desert Ecology,Swiss Institute for Dryland Environmental and Energy Research,Jacob Blaustein Institutes for Desert Research,Ben-Gurion University of the Negev,8499000 Midreshet Ben-Gurion,Israel.
authors.forename: Luther
authors.initials: L
authors.lastname: VAN DER Mescht
authors.affiliation: Wyler Department of Dryland Agriculture,French Associates Institute for Agriculture and Biotechnology of Drylands,Jacob Blaustein Institutes for Desert Research,Ben-Gurion University of the Negev,84990 Midreshet Ben-Gurion,Israel.
authors.forename: Irina S
authors.initials: IS
authors.lastname: Khokhlova
authors.affiliation: Mitrani Department of Desert Ecology,Swiss Institute for Dryland Environmental and Energy Research,Jacob Blaustein Institutes for Desert Research,Ben-Gurion University of the Negev,8499000 Midreshet Ben-Gurion,Israel.
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Warburton
authors.affiliation: Mitrani Department of Desert Ecology,Swiss Institute for Dryland Environmental and Energy Research,Jacob Blaustein Institutes for Desert Research,Ben-Gurion University of the Negev,8499000 Midreshet Ben-Gurion,Israel.
authors.forename: Boris R
authors.initials: BR
authors.lastname: Krasnov
mesh_terms: D000818:Animals; D005247:Feeding Behavior; D005260:Female; D058267:Flea Infestations / Q000469:parasitology / Q000662:veterinary*; D005849:Gerbillinae / Q000469:parasitology*; D058507:Host Specificity; D008297:Male; D051189:Murinae / Q000469:parasitology*; D012098:Reproduction; D012376:Rodent Diseases / Q000469:parasitology*; D005423:Siphonaptera / Q000502:physiology*
keywords: environmental fluctuation; flea; host alternation; rodents