Millepora braziliensis

Millepora braziliensis, known as Brazilian fire coral, is a colonial hydrozoan that constructs calcareous skeletons resembling true stony corals, though it belongs to a distinct lineage of stinging hydrocorals. Colonies typically form encrusting to branching structures in shades of tan, mustard yellow, or pale brown, with a fine, porous surface texture punctuated by tiny pores through which polyps extend to sting passing plankton and deter predators. This species is endemic to Brazil's coral reefs, occurring along the country's biogeographically unique reef province, which harbors many endemic species found nowhere else on Earth due to its isolation from Caribbean and Indo-Pacific reef systems.

The species is classified as Critically Endangered (CR) by the IUCN, with a population trend that is decreasing. Brazilian reefs face compounding pressures including sedimentation from coastal development, agricultural runoff, and mining activity, all of which reduce water clarity and smother coral tissue. Rising sea surface temperatures have triggered repeated bleaching events, and because Millepora braziliensis has a restricted geographic range confined to a limited stretch of coastline, it lacks the buffer of wider distribution that helps other coral species withstand localized disturbances.

On the positive side, growing recognition of Brazil's reefs as a distinct and irreplaceable center of marine endemism has spurred expanded marine protected area coverage along the northeastern coast, along with increased scientific monitoring programs aimed at tracking bleaching resilience and recovery in Brazilian hydrocorals. Researchers are also documenting thermal tolerance variation among coral colonies, offering a foundation for future restoration efforts. Continued investment in water quality management and expanded protected zones offers a meaningful pathway toward stabilizing remaining populations of this ecologically important reef-building species.

This fire coral inhabits shallow tropical reef environments along Brazil's Atlantic coast, typically in clear waters at depths of 1-15 meters. It forms encrusting colonies on hard substrates in areas with moderate to strong water movement.