A single unbranched wire growing off a wall into open water, up to two meters long and often coiled into a loose spiral, with rows of small polyps along it.
It is a black coral, and the name comes from the skeleton rather than the animal: strip the living tissue away and what is left is a hard black core, which is why the group has been harvested for jewelry for centuries and why every black coral is listed on CITES Appendix II. A colony this size is decades old, and it grows a few centimeters a year.
The polyps feed at night on plankton carried past by the current, which is why these grow on walls where water moves and never on sheltered reef.
And a whip is an address. Whip coral shrimps, gobies and squat lobsters live on single strands, each colored to match its own, and a wire that looks bare at a glance usually is not. Run a torch slowly along one and check the shadow side.
- single unbranched wire up to 2 m long, often coiled in a loose spiral
- yellow, green or brown polyps in rows along one side
- growing off a wall into open water, swaying with the surge
- length up to 2 m
