title: Enemies with benefits: parasitic endoliths protect mussels against heat stress.
abstract: Positive and negative aspects of species interactions can be context dependant and strongly affected by environmental conditions. We tested the hypothesis that, during periods of intense heat stress, parasitic phototrophic endoliths that fatally degrade mollusc shells can benefit their mussel hosts. Endolithic infestation significantly reduced body temperatures of sun-exposed mussels and, during unusually extreme heat stress, parasitised individuals suffered lower mortality rates than non-parasitised hosts. This beneficial effect was related to the white discolouration caused by the excavation activity of endoliths. Under climate warming, species relationships may be drastically realigned and conditional benefits of phototrophic endolithic parasites may become more important than the costs of infestation.
authors: Department of Zoology and Entomology, Rhodes University, Grahamstown, 6140, South Africa.
authors: G I
authors: GI
authors: Zardi
authors: CCMAR-Centro de Ciencias do Mar, CIMAR Laboratório Associado, Universidade do Algarve, Campus de Gambelas, Faro, 8005-139, Portugal.
authors: K R
authors: KR
authors: Nicastro
authors: Department of Zoology and Entomology, Rhodes University, Grahamstown, 6140, South Africa.
authors: C D
authors: CD
authors: McQuaid
authors: The Swire Institute of Marine Science and School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China.
authors: T P T
authors: TP
authors: Ng
authors: Department of Zoology and Entomology, Rhodes University, Grahamstown, 6140, South Africa.
authors: J
authors: J
authors: Lathlean
authors: CNRS, UMR LOG 8187, Laboratoire d'Océanologie et de Géosciences, Station Marine, BP 80, Wimereux, 62930, France.
authors: L
authors: L
authors: Seuront
mesh_terms: D000818:Animals; D049872:Bivalvia / Q000469:parasitology / Q000502:physiology*; D005618:Fresh Water; D006790:Host-Parasite Interactions; D000071436:Thermotolerance