@article{fdi:010046012,
  title = {{W}hy do parasitized hosts look different ? {R}esolving the "chicken-egg" dilemma},
  author = {{B}lanchet, {S}. and {M}{\'e}jean, {L}. and {B}ourque, {J}.{F}. and {L}ek, {S}. and {T}homas, {F}. and {M}arcogliese, {D}. {J}. and {D}odson, {J}. {J}. and {L}oot, {G}.},
  editor = {},
  language = {{ENG}},
  abstract = {{P}henotypic differences between infected and non-infected hosts are often assumed to be the consequence of parasite infection. {H}owever, pre-existing differences in hosts' phenotypes may promote differential susceptibility to infection. {T}he phenotypic variability observed within the host population may therefore be a cause rather than a consequence of infection. {I}n this study, we aimed at disentangling the causes and the consequences of parasite infection by calculating the value of a phenotypic trait (i.e., the growth rate) of the hosts both before and after infection occurred. {T}hat procedure was applied to two natural systems of host-parasite interactions. {I}n the first system, the infection level of an ectoparasite ({T}racheliastes polycolpus) decreases the growth rate of its fish host (the rostrum dace, {L}euciscus leuciscus). {R}eciprocally, this same phenotypic trait before infection modulated the future level of host sensitivity to the direct pathogenic effect of the parasite, namely the level of fin degradation. {I}n the second model, causes and consequences linked the growth rate of the fish host (the rainbow smelt, {O}smerus mordax) and the level of endoparasite infection ({P}roteocephalus tetrastomus). {I}ndeed, the host's growth rate before infection determined the number of parasites later in life, and the parasite biovolume then decreased the host's growth rate of heavily infected hosts. {W}e demonstrated that reciprocal effects between host phenotypes and parasite infection can occur simultaneously in the wild, and that the observed variation in the host phenotype population was not necessarily a consequence of parasite infection. {D}isentangling the causality of host-parasite interactions should contribute substantially to evaluating the role of parasites in ecological and evolutionary processes.},
  keywords = {{C}ausal links ; {P}athogenic effects ; {R}eciprocal effects ; {G}rowth rate ; {P}arasite ; {B}ehavior ; {P}ath analysis ; {M}odel selection ; {S}usceptibility},
  booktitle = {},
  journal = {{O}ecologia},
  volume = {160},
  numero = {1},
  pages = {37--47},
  ISSN = {0029-8549},
  year = {2009},
  DOI = {10.1007/s00442-008-1272-y},
  URL = {https://www.documentation.ird.fr/hor/fdi:010046012},
}