Loss of Symbiodinium from bleached soft corals Sarcophyton ehrenbergi, Sinularia sp. and Xenia sp.

Strychar, Kevin B.; Coates, Michael I.; Sammarco, Paul W.; Piva, Terrence J.; Scott, Paul T.

doi:10.1016/j.jembe.2004.12.039

Cited by 59 publications

(55 citation statements)

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“…Moreover, TT of corals has been suggested as a high-priority bioindicator for long- and short-term environmental chronic effects on corals [48], and the loss of zooxanthellae has been proposed as an indicator of stress in corals [53]. Lower values of MI were also found in ramets with FTA removal (T1), which is a condition similar to that shown in corals without application of stressors like exposure to cyanide, bleaching, elevated temperatures and Pink-line syndrome [50], [52], [54], [55].…”

Section: Discussionmentioning

confidence: 80%

Biological Responses of the Coral Montastraea annularis to the Removal of Filamentous Turf Algae

et al. 2013

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Coral reef degradation increases coral interactions with filamentous turf algae (FTA) and macroalgae, which may result in chronic stress for the corals. We evaluated the effects of short (2.5 month) and long (10 month) periods of FTA removal on tissue thickness (TT), zooxanthellae density (ZD), mitotic index (MI), and concentration of chlorophyll a (Chl a) in Montastraea annularis at the beginning and end of gametogenesis. Ramets (individual lobes within a colony) consistently surrounded by FTA and ramets surrounded by crustose coralline algae (CCA) were used as controls. FTA removal reduced coral stress, indicated by increased TT and ZD and lower MI. The measured effects were similar in magnitude for the short and long periods of algal removal. Ramets were more stressed at the end of gametogenesis compared with the beginning, with lower ZD and Chl a cm−2, and higher MI. However, it was not possible to distinguish the stress caused by the presence of FTA from that caused by seasonal changes in seawater temperature. Ramets surrounded by CCA showed less stress in comparison with ramets surrounded by FTA: with higher TT, Chl a cm−2 and ZD, and lower MI values. Coral responses indicated that ramets with FTA suffered the most deleterious effects and contrasted with those measured in ramets surrounded by CCA. According to published studies and our observations, there could be at least six mechanisms associated to FTA in the stress caused to M. annularis by FTA. Owing to the high cover of FTA (in contrast to macroalgae and CCA) in the Caribbean, the chronic stress, the overgrowth and mortality that this functional algal group can cause on M. annularis species complex, a further decline of this important reef-building coral in the Caribbean is expected.

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Section: Discussionmentioning

confidence: 80%

Biological Responses of the Coral Montastraea annularis to the Removal of Filamentous Turf Algae

et al. 2013

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“…The temperature in the experimental tank was raised gradually from 26°C to 34°C over a period of 2 h after which it was maintained at 34°C for a subsequent 6 h. Three control nubbins were maintained in a similar tank as the experimental tank but the temperature was kept at 26°C during the entire course of the experiment. Strychar et al (2005) observed a mortality of Sinularia sp. within 24 h upon exposure to the 34°C temperature.…”

Section: Thermal Stress Experimentsmentioning

confidence: 98%

“…The genus Sinularia is a widely studied genus among octocorals with respect to population genetics (Bastidas et al, 2001), bleaching and symbiont loss (Sammarco and Strychar, 2013;Strychar et al, 2005), cell culture (Khalesi et al, 2008), calcification (Jeng et al, 2011), and various secondary metabolites (Lakshmi and Kumar, 2009). Additionally, there are studies employing mRNA-pool profiling techniques using an informatics-based analysis of kinetic profiles (Hoover et al, 2007;Hoover et al, 2008).…”

Section: Octocoral Gene Expression and Climate Changementioning

confidence: 99%

Evaluation and validation of reference genes for qPCR analysis to study climate change-induced stresses in Sinularia cf. cruciata (Octocorallia: Alcyonidae)

Shimpi

Vargas

Wörheide

2016

Journal of Experimental Marine Biology and Ecology

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“…Zooxanthellae become more mitotic and progress faster through the cell cycle in heat-stressed corals, and after release from the coral (Baghdasarian & Muscatine 2000, Strychar et al 2005; Fig. 6c-e).…”

Section: Algal Exitmentioning

confidence: 99%

Zooxanthellae that open calcium channels: implications for reef corals

McConnaughey¹

2012

Mar. Ecol. Prog. Ser.

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ABSTRACT:Toxins that open cell membrane calcium channels have been found in the dinoflagellate genus Symbiodinium, and likely occur in most zooxanthellae. I used published observations to examine some potentially far-reaching consequences to reef corals. Algal toxins may stimulate coral calcification by opening Ca 2+ channels on the calcifying ectoderm. The coral discharges the resulting protons (Ca 2+ + HCO 3 − → CaCO 3 + H + ) into its coelenteron cavity, where they improve algal bicarbonate and nutrient assimilation. Coupling calcification with autotrophic physiologies contributes to the success of highly calcareous zooxanthellar symbioses, and to their associations with nutrient-poor tropical waters. Nutrient shortages freeze zooxanthellae in the G1 phase of the cell cycle. Dinoflagellates are often most toxic at such times, perhaps because toxins modulate their nuclear mix of cations, to control DNA conformation and activity. Increased Ca 2+ influx into host cells disrupts cell adhesion and induces apoptosis. Zooxanthellae assimilate host nutrients, complete G1, divide, and disperse to new hosts. Nutrient shortages associate with high sea surface temperatures (SST), producing correlations between SST, calcification, and algal exit. Zooxanthellae proliferate when nutrients are abundant, but when nutrients later disappear, usually as SST warms, toxins and the departure of over-abundant zooxanthellae potentially overwhelm the coral and cause coral bleaching.KEY WORDS: Toxin · Coral · Polyketide · Symbiodinium · Calcification · Photosynthesis · Bleaching Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 460: [277][278][279][280][281][282][283][284][285][286][287] 2012 are, however, much weaker than the Ca 2+ influx agonist maitotoxin, which may be the most potent dinoflagellate toxin.Coral symbionts have not yet been examined for toxins, but all analyzed strains of Symbiodinium apparently make Ca 2+ channel openers, so coral symbionts likely do also. Symbiodinium furthermore retains the specialized machinery for making elaborate polyketides despite being a small dinoflagellate with the smallest known dinoflagellate genome (LaJeunesse et al. 2005).Algal toxins appear abundant enough to affect the host coral. Cultured zooxanthellae strain Y-6 contains 75 and 40 µM of zooxanthellatoxins A and B, plus 76 µM symbiodinolide (Nakamura et al. 1993, Kita et al. 2007. These values may not be maxima, due to incomplete yield on toxin extractions, and variable toxin levels in the algae. , and Symbiodinium may do likewise (Fang et al. 1998, Sawyer & Muscatine 2001, DeSalvo et al. 2008, Kita et al. 2010, Yuyama et al. 2011. Ca 2+ channel openers provide a mechanism. Algal colonization presumably succeeds best in hosts with compatible physiologies, especially if toxins suppress harmful host physiologies or stimulate beneficial ones.Many of Symbiodinium's prominent hosts are highly calcareous, including foraminifera, sponges, giant clams, and corals. Symbiotic corals generally ...

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Loss of Symbiodinium from bleached soft corals Sarcophyton ehrenbergi, Sinularia sp. and Xenia sp.

Cited by 59 publications

References 58 publications

Biological Responses of the Coral Montastraea annularis to the Removal of Filamentous Turf Algae

Biological Responses of the Coral Montastraea annularis to the Removal of Filamentous Turf Algae

Evaluation and validation of reference genes for qPCR analysis to study climate change-induced stresses in Sinularia cf. cruciata (Octocorallia: Alcyonidae)

Zooxanthellae that open calcium channels: implications for reef corals

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