Intertidal Sciences blog | Dr Mike Kent | Feb 22nd 2019

Pretty but deadly

 

It may look like a pretty flowering plant, but the Strawberry Anemone (Actinia fragacea) is a deadly animal predator. What appear to be petals rising from a thick stalk are in reality tentacles, 192 of them, armed with barbed stinging cells that act like microscopic harpoons to capture and kill prey. Touch the tentacles, and you can feel the anemone trying to capture you. Unable to penetrate thick skin, they are usually harmless to humans, but it’s probably best not to take the chance if you are ‘thin skinned’ or have a cut.

The group to which Strawberry Anemones belongs is commonly called Beadlet Anemones because of the prominent bright blue bead-like spots (the site of a battery of stinging cells) at the base of each tentacle. Beadlets come in a variety of colours. The commonest is liver brown, but lighter brown and green specimens occur at Baby Bay along with the handsome strawberry form.

All Beadlet anemones have the ability to retract their tentacles at low tide, reducing the surface area exposed to the drying effects of air and enabling them to survive being out of water for several hours.

It may look as immobile as its flowering namesake, but put a Beadlet into an aquarium and you will soon realise that it has the ability to roam, albeit slowly. Once it finds a suitable site, it glues itself with post-it like tenacity onto a hard surface and waits for prey to wander into the clutches of its tentacles.

Cornish folk sometimes refer to Beadlets as ‘blood suckers’ because of the way they engulf any worm, mollusc, small fish or other animal foolish enough to stray too close. Like all other sea anemones, Beadlets have only a simple pouch in which digestion occurs, and there is only one opening which acts as both mouth and anus. If a potential meal comes within reach, tentacles armed with stinging cells draw the quarry into the gut where it is engulfed, soft parts sucked dry and then indigestible remains disgorged.

What, if anything, does this consideration of the ways of the Strawberry Anemone teach us? Perhaps its ability to lie in wait for something good to come along is a living example of patience, one of the greatest of Christian virtues, and one which I really need to work on. But the contrast between the pretty innocuous appearance of the Beadlet and its true nature as a deadly killer brings to mind the words of Matthew:

 

Beware of false prophets, who come to you in sheep’s clothing

but inwardly are ravenous wolves. You will know them by their fruits.

Are grapes gathered from thorns, or figs from thistles?

So, every sound tree bears good fruit, but the bad tree bears evil fruit.

A sound tree cannot bear evil fruit, nor can a bad tree bear good fruit.

Every tree that does not bear good fruit is cut down and thrown into the fire.

Thus you will know them by their fruits.

Matthew 7:15-20