Spine Coral

About

Spine coral (Hydnophora microconos) is one of those understated corals that rewards a closer look. Its colonies form dense, rounded masses covered in evenly spaced little cone-like projections called monticules, each only a couple of millimeters across, giving the surface a distinctly bumpy, almost knobbled texture unlike most other stony corals. Coloration runs toward the muted end of the spectrum, creams, browns, and occasional greens, so this isn't a coral you pick for bold color, but the structural interest it brings to a mixed reef is real. In the wild it turns up across a wide band of the Indo-Pacific, from the Red Sea to the central Pacific, thriving in lagoons, sheltered reef slopes, and even wave-washed flats, which tells you something about its general toughness. Like most large-polyp and small-polyp stony corals, its polyps stay retracted through the day and only emerge after lights go down. In the aquarium it asks for moderate light and flow, and while it's not a beginner coral, a keeper who's comfortable with basic reef water quality and placement shouldn't find it particularly demanding. It's a solid, honest choice for adding three-dimensional structure to an established reef system.