FISH OF THE WEEK - Ball Tentacle Anemones (Corallimorphidae).

Invertebrate week! We have the ball tentacle anemones (Corallimorphidae).

These animals are commonly called anemones despite being more closely related to reef building stony corals, not true anemones. Corallimorphs in the family Corallimorphidae behave and look very much like their anemone cousins. The species in this family range in size from a few centimeters to over a foot (30cm+) in diameter. Their tentacles have ball-shaped tips loaded with stinging nematocysts that are used to capture prey, some having stinging power comparable to large fish-eating anemones. They can move around to find suitable places to feed, usually under reef ledges since they are not photosynthetic. Paracorynactis is known to feed on starfish, even the large coral-eating crown of thorns starfish is turned into a meal. Ball tentacle "anemones" have also been found to eat plankton and other small invertebrates.

A few species from this family make it into the aquarium trade such as the common hitchhiker Corynactis caribbeorum, the coldwater strawberry anemone Corynactis californica, and Paracorynactis hoplites. Small hitchhiking species typically thrive without any extra care but will still benefit from target feeding. Larger species must be carefully chosen as some will kill and eat fish.

Sources and further reading:
- https://reefbuilders.com/2021/04/23/paracorynactis-ball-tentacle-anemone-is-a-starfish-killer/
- https://reefbuilders.com/2021/12/07/i-got-stung-by-a-ball-tentacle-shroom/
- https://www.marinespecies.org/aphia.php?p=taxdetails&id=100685
- https://youtu.be/xs7I_dko-JE?si=LUyrxzvSXDw7X5Bj