Day 118 - Amazing Enigmatic Anemones

Hi All,

Day 118 and another little treasure from my rock pool exploration at Whitby.

Before I start though, I thought I'd mention another little fact about Whitby. Whitby was the place that Captain Cook, one of our most famous explorers, learnt most of his sailing skills. It was also where his ships HMS Endeavour and HMS Resolution were built.

So back to my rock pools. I found another fascinating creature lurking in one pool. It was a bit more colourful than the Limpets or the Barnacles but hard to photograph as it was under the water. I'm talking today about sea anemones. What did I find out about these amazing creatures:

Beadlet Anemone (Actinia equina)

• Anemones are closely related to corals and jellyfish.

• As you can just make out in the picture they have a cylindrical body. This attaches itself to rocks using a sticky foot on its base. On top they have lots of tentacles surrounding a central mouth.

• The species in the picture, the Beadlet Anemone, can have up to 192 tentacles arranged in 6 circles.

• It is well adapted to living in tidal zones as it will stand high temperatures and some dessication (drying out). 

• They are carnivorous and hunt for food by waiting for prey to pass and they use their venomous tentacles to sting and kill their prey.

• Their tentacles are very sensitive and are triggered by touch causing a harpoon like filament to be fired into the prey. Once immobilised by the venom the tentacles move the prey towards the mouth.

• New gene research has found that sea anemones are half plant and half animal though they are classed as animals.

• There are over 1000 species of sea anemones and they range in size from half an inch to six feet!

• The Beadlet Anemone is territorial and will fight with others to protect its patch. One will sting another until they crawl away or drop off the surface they are on.

• They can live a long time, some species can live up to 50 years old.

• Some species are invertebrates and do not have a backbone. Most of their body, like us, is made up of water.

• There are some examples of them working together with fish. The clownfish has a covering of mucus which stops it getting stung by the Anemone. It shelters in the tentacles getting protection from predators. The Anemone benefits by feeding on the scraps of the fish's meal. This is known as symbiotic alliance.

Here's a few links to more information if you want to find out more about these creatures.

Sea Anemones - half plant half animal

Marine Life Information Network - Beadlet Anemone

Hope you enjoyed,

Z.