Slipper Coral

About

Slipper coral (Herpolitha limax) is one of those corals that immediately makes you do a double-take in the display tank. Rather than attaching to rock like most reef-building corals, it lives as a free-lying, unattached colony on sandy reef slopes and lagoon floors throughout the Indo-West Pacific. The same kinds of habitats where fungiid corals are common. Its shape is the first thing you notice: typically an elongated, tongue-like or boomerang form with rounded ends, though some colonies branch into Y, T, or even X shapes as they grow. Running down the length of the colony is a central groove called the axial furrow, lined with mouths, and additional mouths dot the surface beyond it. Coloration tends toward earthy tones, pale tan, medium brown, or a muted greenish-brown, so it reads as subtle rather than flashy. Like many LPS corals, it only extends its tentacles after dark, so you'll see more activity during an evening viewing session. In the aquarium this is considered a beginner-accessible coral, doing well under moderate light with gentle, low-intensity flow. Because it rests on the substrate rather than attaching to rock, placement on open sand is more appropriate than wedging it into a crevice.