They can occasionally move quickly by ‘kinda’ jumping and being carried by the current. This might be in response to a predator.
Side note 2:
Some sea anemones form colonies, so I lied when I said they are a single polyp, just most species are.
Side note 3: Yes, another one.
Sea Anemones have stinging cells on their tentacles, for feeding and protection. They also have other protecting stinging cells that can project from the body, these are called acontia.
In Maine there are three sea anemones I would consider common, at least for shoreline observers.
1. The Silver-spotted Anemone Aulactinia stella(Verrill, 1864), once placed in the genus Bunodactis.
In Maine, on Mount Desert Island, within Acadia National Park, is an anemone haven called, or was once called Anemone Cave. I write, “once called Anemone Cave”, because that was how it was labeled on the National Parks Service maps. The site, map label, signs, and walkways leading too, have since disappeared and it is no longer an official park attraction. The first two anemone photos above were taken in the cave. The Frilled Anemone picture I stole from the web.
I think that conservation mindedness was the reason for pulling the cave from the maps. I have heard tales that hobbyist attempted collecting anemones for their aquaria (or to sell). Pulling an anemone from the rock usually damages it substantially. But that isn’t even necessary for them to be damaged by humans. They are small, delicate, and many human visiting the few, relatively small, tide pools that can house hundreds of these amazing creatures certainly was a cause for concern.
When I visited the cave in July one species dominated the pools, the red anemone Urticina felina. The much more interesting looking silver-spotted anemone, Aulactinia stella, is also there. I found none of Frilled Anemone, Metridium senile, though I have heard that they are sometimes found there as well. This last species, Metridum senile, is the most commonly encountered species elsewhere on the island. They are often found on docks on the sections that stay within the water when the tide goes out. They are also the only anemone I have seen within the silk covered substrate line the underwater slopes of Somes Sound.
Quick diving tip, the edges of the sound are fine silt, your flippers will easily stir this up and you’ll not be able to see through all the suspended particles.
At least two other anemones can be found in Maine, Diadumene lineata (Verrill, 1869), the Striped Anemone, and Diadumene leucolena(Verrill, 1866), The White Anemone or sometimes ghost anemone, I’m going with white since the word root leuco means white. This anemone is moving into areas it previously hasn’t been seen—up the St. Lawrence Seaway for example but I do not know about the level of its Invasiveness.
A last note about anemones. They, like corals, can bleach. And, as with corals, this is primarily due to warming waters. The cave houses lots of anemones and one reason is because it stays cool and anemones prefer that habitat. I found a few notes online that suggest that the number of anemones in the cave has diminished in recent years. I can't find a true reference on this; if anyone has one I'd love to see it. I counted 129 Northern Red, and just 4 Silver-spotted. I found no Frilled Anemones.
No references this month because I’m a bit lazy and trying to work on a book.