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Elkhorn Coral (Acropora palmata)

Marine invertebrateCnidarianStony coralConservation priority

Elkhorn coral (Acropora palmata) with broad, antler-like branches on a reef.

Elkhorn coral (Acropora palmata), Florida Keys.

Image: Jstuby, CC0, via Wikimedia Commons.

Overview

Elkhorn coral (Acropora palmata) is a large branching stony coral with broad, flattened branches that spread like the antlers of an elk. It was once one of the most important reef-building corals of the Caribbean, forming dense stands in shallow, high-energy water and creating the reef crest that shelters coastlines and marine life behind it.

As with other reef corals, each colony is a community of tiny polyps sharing a hard skeleton and partnering with symbiotic algae for energy. Its sturdy, flattened branches are adapted to withstand strong waves.

Conservation note: elkhorn coral has suffered severe declines and is widely recognised as critically endangered, affected by disease, bleaching from warming seas, storms, and other pressures. It is a priority for reef restoration. Verify current status at authoritative sources.

Habitat & Range

Elkhorn coral grows in warm, clear, shallow Caribbean and western Atlantic waters, typically in the wave-swept zone near the reef crest. Its strong, flattened branches are well suited to these high-energy shallows, where it historically built extensive reef framework.

Diet

Like other reef-building corals, elkhorn coral captures plankton with its polyps' stinging tentacles and obtains much of its energy from the symbiotic algae living in its tissues, which photosynthesise in the bright, shallow water it favours.

Behavior

Elkhorn coral grows relatively quickly for a coral and, like its staghorn relative, can reproduce both by spawning and by fragmentation — broken pieces can reattach and grow. This makes it suitable for coral nursery and restoration efforts, which aim to rebuild the reef crests it once dominated.

Human Interaction & Conservation

Beyond its ecological role, elkhorn coral helps protect shorelines by absorbing wave energy at the reef crest, so its loss has consequences for coastal communities as well as marine life. Restoration projects grow and replant it, while reducing warming and disease pressures remains essential. Consult authoritative sources for current status.

More photos of the elkhorn coral

Elkhorn coral colony spreading across a shallow reef.

Elkhorn coral (Acropora palmata).

Image: Jstuby, CC0, via Wikimedia Commons.

Frequently Asked Questions — Elkhorn Coral

How is elkhorn coral different from staghorn coral?
Both are branching Caribbean Acropora corals, but elkhorn coral has broad, flattened branches (like an elk's antlers) and tends to grow in shallow, wave-swept reef crests, while staghorn coral has slender, cylindrical branches. Both are fast-growing reef builders and both are critically endangered.
Why does elkhorn coral matter for coastlines?
Elkhorn coral builds the shallow reef crest that absorbs wave energy before it reaches shore. Healthy stands therefore help protect coastlines from erosion and storm damage, so losing them affects people as well as reef wildlife.
Why is elkhorn coral endangered?
It has declined steeply due to disease, bleaching driven by warming seas, storm damage, and other pressures, and is widely recognised as critically endangered. Its shallow, exposed habitat and branching form add to its vulnerability.
Can elkhorn coral be restored?
Yes, in part. Because fragments can reattach and grow, restoration programmes cultivate elkhorn coral in nurseries and transplant it onto reefs. Long-term recovery still depends on reducing the underlying threats, especially ocean warming and disease.

Sources and further reading

Authoritative wildlife references used for general educational context. Conservation status should always be verified against current IUCN Red List data. External links open in a new tab.