title: Does coral disease affect symbiodinium? Investigating the impacts of growth anomaly on symbiont photophysiology.
abstract: Growth anomaly (GA) is a commonly observed coral disease that impairs biological functions of the affected tissue. GA is prevalent at Wai 'ōpae tide pools, southeast Hawai 'i Island. Here two distinct forms of this disease, Type A and Type B, affect the coral, Montiporacapitata. While the effects of GA on biology and ecology of the coral host are beginning to be understood, the impact of this disease on the photophysiology of the dinoflagellate symbiont, Symbiodinium spp., has not been investigated. The GA clearly alters coral tissue structure and skeletal morphology and density. These tissue and skeletal changes are likely to modify not only the light micro-environment of the coral tissue, which has a direct impact on the photosynthetic potential of Symbiodinium spp., but also the physiological interactions within the symbiosis. This study utilized Pulse amplitude modulation fluorometry (PAM) to characterize the photophysiology of healthy and GA-affected M. capitata tissue. Overall, endosymbionts within GA-affected tissue exhibit reduced photochemical efficiency. Values of both Fv/Fm and ΔF/ Fm' were significantly lower (p<0.01) in GA tissue compared to healthy and unaffected tissues. Tracking the photophysiology of symbionts over a diurnal time period enabled a comparison of symbiont responses to photosynthetically available radiation (PAR) among tissue conditions. Symbionts within GA tissue exhibited the lowest values of ΔF/Fm' as well as the highest pressure over photosystem II (p<0.01). This study provides evidence that the symbionts within GA-affected tissue are photochemically compromised compared to those residing in healthy tissue.
authors: Tropical Conservation Biology and Environmental Science, University of Hawai'i at Hilo, Hilo, Hawai'i, United States of America. johnhr@hawaii.edu
authors: John Henrik Robert
authors: JH
authors: Burns
authors: Toni Makani
authors: TM
authors: Gregg
authors: Misaki
authors: M
authors: Takabayashi
mesh_terms: D000818:Animals; D037421:Anthozoa / Q000254:growth & development*; D002940:Circadian Rhythm; D004141:Dinoflagellida / Q000235:genetics / Q000378:metabolism*; D005838:Genotype; D010788:Photosynthesis; D013559:Symbiosis
references: Dis Aquat Organ. 2006 Jun 12;70(1-2):155-60
references: 16875402
references: Environ Microbiol. 2002 Jun;4(6):318-26
references: 12071977
references: J Phycol. 2008 Apr;44(2):526-38
references: 27041207
references: J Invertebr Pathol. 2007 Mar;94(3):218-21
references: 17223127
references: J Exp Bot. 2000 Apr;51(345):659-68
references: 10938857
references: Proc Biol Sci. 2008 Jun 22;275(1641):1359-65
references: 18348962
references: Biol Bull. 2004 Apr;206(2):61-4
references: 15111360
references: Proc Biol Sci. 2006 Sep 22;273(1599):2305-12
references: 16928632
references: Dis Aquat Organ. 2008 Jan 24;78(3):255-64
references: 18380225
references: Am Nat. 2003 Oct;162(4 Suppl):S51-62
references: 14583857
references: PLoS One. 2011 Jan 05;6(1):e15854
references: 21246044
references: PLoS One. 2013 Apr 22;8(4):e61492
references: 23630594
references: Science. 1999 Sep 3;285(5433):1505-10
references: 10498537
references: Dis Aquat Organ. 2006 Mar 23;69(1):9-21
references: 16703762
references: PLoS One. 2011;6(12):e28854
references: 22205976
references: PLoS Biol. 2007 Jun;5(6):e124
references: 17488183
references: Proc Biol Sci. 2004 Aug 22;271(1549):1757-63
references: 15306298
references: Science. 1994 Sep 9;265(5178):1547-51
references: 17801530
references: Appl Opt. 2010 Sep 20;49(27):5032-42
references: 20856275
references: Trends Ecol Evol. 1998 Nov 1;13(11):438-43
references: 21238385
references: Dis Aquat Organ. 2006 Mar 23;69(1):1-7
references: 16703761
references: J Natl Cancer Inst. 1986 May;76(5):895-912
references: 2871213
references: Trends Ecol Evol. 1988 May;3(5):106-11
references: 21227159