Heterotrophic Strategies in Coral Reef Ecosystems

Coral reef organisms employ a spectrum of feeding modes ranging from strict autotrophy through algal symbiont photosynthesis to heterotrophy via the capture of planktonic prey and organic particulates. Many reef‐building corals are mixotrophic, adjusting the balance of photosynthetic and heterotrophic nutrition in response to environmental variability. Heterotrophic strategies include direct ingestion of zooplankton, particle‐associated microbes and dissolved organic matter, each contributing to energy budgets, tissue repair and skeletal growth. By modulating feeding behaviour, corals can buffer against declines in symbiont photosynthesis during thermal stress, seasonal shifts or periods of low light. Spatial gradients in primary production and local hydrodynamics influence food availability, driving differences in heterotrophic reliance among species and populations. Understanding these strategies is crucial for predicting reef resilience, guiding restoration efforts and informing management of reefs under threat from climate change and coastal development.

Research from Nature Portfolio

In a study of threatened Acropora palmata, researchers mapped physiological and microbiome variation across a 350 km reef gradient. Sites with frequent upwelling and elevated plankton supply fostered greater heterotrophic uptake, enhanced coral growth and improved transplant success, indicating that local oceanographic conditions modulate feeding capacity and restoration outcomes. Another investigation into Stylophora pistillata subjected to heat stress revealed that heterotrophic nutrient supply accelerates the recovery of normal carbon exchange between host and symbiont after bleaching. Corals receiving supplemental prey exhibited stronger photosynthate translocation, supporting metabolic demands and partially mitigating declines in calcification during thermal anomaly.

Heterotrophic Strategies in Coral Reef Ecosystems publication trend

The graph below shows the total number of articles in heterotrophic strategies in coral reef ecosystems across all publications each year (not limited to Nature Index journals).

Technical terms

Mixotrophy: A nutritional strategy combining autotrophic photosynthesis and heterotrophic feeding.

Holobiont: The functional unit comprising a coral host and its associated microbial and algal symbionts.

Trophic plasticity: The capacity to adjust feeding modes along the autotrophy–heterotrophy continuum.

Photosynthate: Organic carbon compounds produced by algal symbionts and translocated to the coral host.

Isotopic niche: A multi‐dimensional representation of dietary sources inferred from stable isotope ratios.

References

1. Heterotrophy, microbiome, and location effects on restoration efficacy of the threatened coral Acropora palmata. Communications Earth & Environment (2023).
2. Heterotrophy promotes the re-establishment of photosynthate translocation in a symbiotic coral after heat stress. Scientific Reports (2016).
3. Changes within the coral symbiosis underpin seasonal trophic plasticity in reef corals. ISME Communications (2025).
4. Unveiling the importance of heterotrophy for coral symbiosis under heat stress. mBio (2024).
5. Gradients in Primary Production Predict Trophic Strategies of Mixotrophic Corals across Spatial Scales. Current Biology (2018).