Page 216 - Atlas Of The World's Strangest Animals

216 ATLAS OF THE WORLD’S STRANGEST ANIMALS

With their bold colours and flower-like shape, it’s easy to
Sea anemone habitats
mistake anemones for bits of marine flora, gently swaying
back and forth with the tides.The truth about these
amazing aquatic predators, though, is much more strange.
Sea anemones spend most of their time anchored to the
sea bottom (or any convenient structure) by an adhesive
foot, called a pedal disk. Generally their bodies are
colourful columns, tipped by a mass of tentacles.These
tentacles are loaded with stinging organs called
nematocysts. Inside each of these specialized cells is a
coiled, threadlike tube lined with barbed spines.When
one of the anemones’ tentacles touches prey, the
nematocyst is triggered.Water rushes into the capsule,
which expels the barbed thread, like a harpoon being
shot from a gun.The spine penetrates the prey’s skin,
injecting it with paralyzing poison. Prey can then be
safely pulled into the anemones’ mouth, which lies at
the centre of the tentacles.
When it’s time to breed, anemones use both sexual and
asexual reproduction, depending on the species. In sexual
reproduction, males release sperm and females release eggs. and it has been suggested that sea anemones could
Once fertilized, the eggs develop into young called theoretically live forever!
planulae, and these eventually settle onto the sea bed to
feed, like adult anemones.Asexual reproduction usually Friends and anemones
involves a portion of the adult breaking away to form The world symbiosis means ‘living together’ and is
what is effectively a ‘clone’. commonly used to describe complex relationships
However it has been created, the new anemone can between unrelated species. Mutualistic symbiosis is where
look forwards to a lengthy life.As long as the water both species benefit by working or living together, and it
remains unpolluted and it is not eaten, an anemone can is practised by a diverse cross-section of life.
live for decades.There has been very little research done Unlike their relatives, the corals, who live in dense
on this topic but some specimens are at least 50 years old, colonies, most sea anemone are solitary animals.Yet, within

A harmless-looking cluster of anemone cling to the submerged A small fish brushes past,which triggers the anemone’s stinging
leg of a jetty, like a clump of colourful seaweed. cells. Inside each is a small, but deadly, barbed ‘harpoon’.

(c) 2011 Marshall Cavendish. All Rights Reserved.