title: Development and infectious disease in hosts with complex life cycles.
abstract: Metamorphosis is often characterized by profound changes in morphology and physiology that can affect the dynamics of species interactions. For example, the interaction between a pathogen and its host may differ depending on the life stage of the host or pathogen. One pathogen that infects hosts with complex life cycles is the emerging fungal pathogen of amphibians, Batrachochytrium dendrobatidis (Bd). We sought to determine how conditions at the larval stage can affect variation in development and patterns of Bd infection across amphibian life stages. We used outdoor experimental mesocosms to simulate natural pond habitats and manipulated the presence of Bd, the larval density, and the number of host species in larvae of two co-occurring amphibian species (Rana cascadae and Pseudacris regilla). We found that infection differed between species throughout development; P. regilla consistently had higher infection severity compared to R. cascadae. Additionally, while up to 100% of larvae were infected, only 18.2% of R. cascadae and 81.5% of P. regilla were infected after metamorphosis. This indicates that amphibians have the ability to recover from Bd infection as they undergo metamorphosis. Higher larval densities in P. regilla led to a shorter larval period, and individuals with a shorter larval period had lower infection severity. This led to a trend where P. regilla larvae reared at high densities tended to have lower infection prevalence after metamorphosis. We also found that exposure to Bd increased larval mortality and prolonged the larval period in P. regilla, indicating that P. regilla are susceptible to the negative effects of Bd as larvae. This study demonstrates that host density, species composition, and pathogen exposure may all interact to influence development and infection in hosts with complex life cycles.
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA. searlec@umich.edu
authors.forename: Catherine L
authors.initials: CL
authors.lastname: Searle
authors.forename: Gisselle Yang
authors.initials: GY
authors.lastname: Xie
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Blaustein
mesh_terms: D000818:Animals; D008411:Chytridiomycota / Q000472:pathogenicity; D003141:Communicable Diseases / Q000382:microbiology*; D006801:Humans; D007814:Larva / Q000254:growth & development / Q000382:microbiology; D008018:Life Cycle Stages / Q000502:physiology*; D008675:Metamorphosis, Biological / Q000502:physiology; D011898:Ranidae / Q000254:growth & development* / Q000382:microbiology
references.citation: Ecol Lett. 2011 Feb;14(2):125-31
references.pmid: 21091597
references.citation: Oecologia. 2003 Mar;134(4):596-604
references.pmid: 12647133
references.citation: J Wildl Dis. 2004 Jul;40(3):420-8
references.pmid: 15465708
references.citation: J Wildl Dis. 2008 Jul;44(3):716-20
references.pmid: 18689660
references.citation: PLoS One. 2013;8(1):e54490
references.pmid: 23382904
references.citation: Science. 2000 Jan 21;287(5452):443-9
references.pmid: 10642539
references.citation: PLoS One. 2012;7(3):e33567
references.pmid: 22428071
references.citation: Proc Natl Acad Sci U S A. 2010 May 25;107(21):9695-700
references.pmid: 20457916
references.citation: Oecologia. 1988 Feb;75(1):67-72
references.pmid: 28311835
references.citation: PLoS One. 2011 Feb 02;6(2):e16675
references.pmid: 21311771
references.citation: J Wildl Dis. 2005 Apr;41(2):275-90
references.pmid: 16107661
references.citation: Dis Aquat Organ. 2009 Jan 28;83(1):1-9
references.pmid: 19301630
references.citation: Dis Aquat Organ. 2004 Oct 21;61(1-2):75-83
references.pmid: 15584413
references.citation: Conserv Biol. 2009 Oct;23(5):1242-52
references.pmid: 19774709
references.citation: Dis Aquat Organ. 2003 Jun 20;55(1):65-7
references.pmid: 12887256
references.citation: Ecohealth. 2009 Dec;6(4):565-75
references.pmid: 20135192
references.citation: Dis Aquat Organ. 2007 Aug 13;77(1):1-9
references.pmid: 17933392
references.citation: J Anim Ecol. 2007 Jul;76(4):711-21
references.pmid: 17584377
references.citation: Proc Natl Acad Sci U S A. 2008 Aug 12;105 Suppl 1:11466-73
references.pmid: 18695221
references.citation: Proc Biol Sci. 2010 Feb 22;277(1681):519-28
references.pmid: 19864287
references.citation: Proc Natl Acad Sci U S A. 2011 Sep 27;108(39):16322-6
references.pmid: 21930900
references.citation: Dis Aquat Organ. 2007 Jan 18;73(3):175-92
references.pmid: 17330737
references.citation: J Herpetol. 2009;43(3):551-554
references.pmid: 29276310
references.citation: Dis Aquat Organ. 2007 May 9;75(3):201-7
references.pmid: 17629114
references.citation: Am Nat. 2004 Nov;164 Suppl 5:S79-89
references.pmid: 15540144
references.citation: Dis Aquat Organ. 2005 Dec 30;68(1):47-50
references.pmid: 16465833
references.citation: Dis Aquat Organ. 2004 Aug 9;60(2):141-8
references.pmid: 15460858
references.citation: Proc Natl Acad Sci U S A. 2002 Aug 20;99(17):11270-4
references.pmid: 12172004
references.citation: Dis Aquat Organ. 2005 Jan 25;63(1):69-76
references.pmid: 15759802
references.citation: PLoS One. 2011;6(9):e24991
references.pmid: 21949824
references.citation: Oecologia. 1982 Jan;54(1):96-100
references.pmid: 28310999
references.citation: Oecologia. 2008 Mar;155(3):641-9
references.pmid: 18157552
references.citation: Biol Lett. 2006 Sep 22;2(3):455-9
references.pmid: 17148429
references.citation: Proc Natl Acad Sci U S A. 2006 Feb 28;103(9):3165-70
references.pmid: 16481617
references.citation: Evolution. 2004 Jun;58(6):1251-60
references.pmid: 15266974
references.citation: Ecology. 2006 Jul;87(7):1671-83
references.pmid: 16922318
references.citation: Ecohealth. 2009 Jun;6(2):209-18
references.pmid: 19526269
references.citation: Conserv Biol. 2011 Oct;25(5):965-74
references.pmid: 21732979