Glossary
Sweeper tentacle
A long stinging tentacle some corals extend at night to clear their neighbours.
Euphyllia are notorious for it. The skeleton tells you nothing about the reach: leave a hand’s width around a torch or you will find out which of the two is more aggressive.
Related terms
- LPSLarge-polyp stony corals — fleshier, more forgiving, and easier to photograph honestly.
- Polyp extensionHow far the animal opens its tentacles — the fastest read on whether it is comfortable.