Lesser Valley Coral

Overview

The Lesser Valley Coral (Platygyra lamellina) is a colonial stony coral belonging to the family Merulinidae. It is widely recognized for its distinctive, brain-like appearance, characterized by a surface of meandering ridges and grooves that provide essential structure to coral reef ecosystems throughout the Indo-Pacific region.

Distribution & habitat

This species is found across the Indo-Pacific, including the Red Sea and coastal waters of Australia. It typically inhabits shallow reef environments, with a preference for reef flats and back-reef margins where it can form massive, boulder-shaped mounds or occasionally flat, plate-like colonies.

Appearance

Colonies are defined by their meandroid (maze-like) corallites. The walls of these valleys are thick—often up to one and a half times the width of the valleys themselves—and feature neatly arranged, slightly protruding septa that cross the valley walls. While coloration can vary, colonies are commonly found in shades of brown, sometimes featuring contrasting grey or green valleys.

Biology & behavior

As a photosynthetic coral, it relies on symbiotic zooxanthellae for energy. It is considered a semi-aggressive species; during nighttime hours, it may extend sweeper tentacles to defend its space or compete with neighboring corals. The species is also known to produce significant amounts of mucus as part of its biological maintenance.