Lesser Knob Coral

About

The lesser knob coral (Cyphastrea hexasepta) is a compact, massive-growing coral that rewards a closer look. Colonies form solid, boulder-like structures with a surface that ranges from relatively even to notably irregular depending on conditions. What makes it visually interesting up close is the texture. The coenosteum between corallites is covered in prominent, elaborately shaped spines, giving the whole colony a rough, almost granular appearance. The corallites themselves are widely spaced and range from flush with the surface to distinctly tubular and angled, which gives colonies a slightly lopsided, organic character. Calices are small, and the septa typically run in two cycles, usually with six primary septa per corallite though this can vary across the same colony. In terms of color, expect mottled brown. Nothing flashy, but the textural detail more than compensates for the understated palette. In the wild it turns up in shallow reef environments, where it can handle a range of light and flow conditions. In the aquarium, moderate lighting and moderate flow suit it well. This is an intermediate-level coral rather than a beginner pick, but it's not especially demanding compared to many other reef species, making it a solid choice for hobbyists who have moved past the basics.