What is the difference between tentacles and acontia in sea anemones?

Tentacles in sea anemones are the flexible, elongated structures that surround their mouths and are primarily used for capturing prey and defense. Acontia, on the other hand, are specialized, thread-like structures that can be extended from the anemone's body, often containing stinging cells (nematocysts), which they use for both capturing prey and deterring predators. While tentacles are more prominent and visible, acontia can be deployed as a secondary line of defense.