Flexible Symbiotic Associations of Symbiodinium With Five Typical Coral Species in Tropical and Subtropical Reef Regions of the Northern South China Sea

Abstract

The coral symbiont Symbiodinium plays important roles in the adaptation of coral to environmental changes. However, coral-Symbiodinium symbiotic associations are not well-understood in the South China Sea (SCS) whilst considering environmental factors and host taxa. In this study, next-generation sequencing of the internal transcribed spacer region 2 (ITS2) marker gene was used to explore the symbiotic associations between Symbiodinium and five typical coral species across tropical and subtropical reef regions of the SCS. The results showed that Acropora sp., Galaxea fascicularis, Platygyra lamellina, and Sarcophyton glaucum exhibited distinct Symbiodinium compositions between tropical and subtropical reef regions, whereas Porites lutea had stable Symbiodinium compositions. More heterogeneous Symbiodinium compositions among different coral species were observed in the tropical region, but there were no statistically significant differences in Symbiodinium compositions among different coral species in subtropical reef regions. There was a correlation between the Symbiodinium compositions and environmental factors, except for the composition of P. lutea. Symbiodinium subclades D1, D2, C71, C71a, C21, C3b, and C161 were primarily explained by the seawater temperature, nitrate, ammonia, and phosphate. Several host-specific Symbiodinium subclades (e.g., C15, C15.6, and C91) were observed in P. lutea as well. The findings of this study demonstrate the relationship of Symbiodinium diversity with coral hosts and the environment are helpful for elucidating the adaptation of corals to global climate change and anthropogenic disturbance.

Unraveling Heterogeneity of Coral Microbiome Assemblages in Tropical and Subtropical Corals in the South China Sea

“…In our study, one exception was P. lutea which exhibited relative stable microbiome composition between tropical and subtropical reefs (p = 0.142), revealing inter-species differences as well. In the Indo-Pacific Ocean, previous studies have implied that Porites-algae symbiotic associations were stable over broad geographical scales and temperature ranges, and Porites holobiont was persistent to elevated SST [38][39][40]. Taken together, those results suggested that Porites may have more conserved microbiome than other coral species.…”

Endosymbiont diversity and community structure in Porites lutea from Southeast Asia are driven by a suite of environmental variables

“…Durusdinium richness is also highest in Singapore. It is well-established that Durusdinium species are tolerant against thermal stress (Chen et al 2003;Gong et al 2018;Brian et al 2019). Studies also suggest that the genus is a possible indicator of marginal reef environments and that its members tend to be more prevalent on reefs with higher levels of environmental disturbance (Chen et al 2003;Stat and Gates 2011).…”

“…The processes structuring coral symbiont communities can be complex and wide-ranging (Archer et al 2019), in addition to temperature and cloud cover, Symbiodiniaceae assemblages can be influenced by variables including water chemistry, oceanic processes, sedimentation and pollution (Stat and Gates 2011;Yang et al 2012;Keshavmurthy et al 2017;Gong et al 2018). Seasonally, the varying effects of the northeast monsoon (December to March) and southwest monsoon (June to September) can have different biophysical influences on the three studied regions.…”

“…Porites lutea is an ecologically important and widespread coral species that contributes substantially to the formation and maintenance of coral reefs throughout the Indian and Pacific Oceans (Stat and Gates 2011;Tanzil et al 2013). The composition of Symbiodiniaceae communities hosted by this species is known from Japan, Persian Gulf, Red Sea, northern South China Sea, Gulf of Thailand and the Great Barrier Reef (LaJeunesse et al 2004a;Hume et al 2013;Gong et al 2018;Chankong et al 2019;Terraneo et al 2019). However, despite the high levels of biodiversity in Southeast Asian marine ecosystems, only limited work using denaturing gel gradient electrophoresis (DGGE)which is limited in its ability to detect symbiont types of low abundancehas been performed in Singapore (Tanzil et al 2016), and currently no data exist for corals from Peninsular Malaysia.…”

Coral Reef Resilience in Taiwan: Lessons from Long-Term Ecological Research on the Coral Reefs of Kenting National Park (Taiwan)

“…At the community level, Cladocopium spp. were the dominant Symbiodiniaceae associated with corals in KNP (previously Clade C), as they are elsewhere in the Pacific and South China Sea [123][124][125]. No matter the molecular technique applied to phylotype Symbiodiniaceae, the results consistently shows that Cladocopium sp.…”