The life of a barnacle
A barnacle spends most of its life standing on its head and waving its
legs!
When a baby barnacle hatches out of its egg it has one eye and twelve
legs. For several weeks it swims about in the plankton, eating tiny
plants. A little at a time it
goose barnacles
changes, until it has two large antennae, three eyes, twenty-four legs,
and a two-piece shell.
ribbed barnacles on a snail
At this stage, the barnacle begins to search for a home. It needs a
hard, rough surface where the water moves by swiftly. It may choose a
dock, the shell of a sea turtle, a rock, or the bottom of a ship. For a
time, the barnacle \”tests” its new home by walking about and touching
its antennae to the surface. As it does this, drops of a sort of glue
begin to ooze out of the antennae.
Suddenly the barnacle finds its head stuck to the surface! It kicks and
struggles to free itself, but it’s stuck for good. Barnacle glue is the
strongest glue in the world!
Barnacles that stick themselves to the bottom of ships are a big
problem. They slow down a ship, so they have to be scraped off. And this
is no easy job.
Once a barnacle is stuck down, it loses its shell. But a liquid that
flows out of its body hardens and forms a new boxlike shell. The
barnacle also loses its eyes. But it still has twenty-four legs. And it
uses its legs to catch food.
The legs are covered with stiff hairs. By sticking its legs out of its
shell and waving them, the barnacle catches tiny plants and animals in
the hairs. Then it pulls its legs back into its shell and eats the food
it has caught. And this is how it spends the rest of its life.
Each barnacle is both male and female combined. So every barnacle can
lay eggs. And it lays its eggs two or three times a year—ten or
fifteen thousand at a time!
