Solar-Powered Sea Slugs

© Learning A–Z
The plant and animal world abounds with amazing organisms,
but it would be hard to find creatures more strangely beautiful
than sea slugs.
p r e s e n t e d b y Science a-z a d i v i s i o n o f L e a r n i n g A - Z
Solar-Powered Sea Slugs
© Jordi Regàs
The species Berghia coerulescens could almost be
used as a bracelet. Its body parts that look like horns
are actually organs it uses to taste and smell chemicals
in the water.
By Ron Fridell
It’s a plant. It’s an animal.
It’s a . . . planimal?
© Andrew G. Wood/
Photo Researchers, Inc.
The species Glaucus atlanticus spends its
life hanging upside down on the ocean’s
surface. A gas bubble in its belly keeps it up
as the currents and winds move it along.
It’s sometimes called the blue dragon.
What do the sea slugs below look like to you?
© iStockphoto.com/cbpix
© iStockphoto.com/Dave Bluck
It’s a sea slug known as Elysia
chlorotica, a hybrid species that
lives in ocean waters along the
eastern United States. Like an
animal, it eats food. But like a
plant, it also manufactures its
own food supply.
© Nick Curtis and Ray Martinez
www.sciencea-z.com
© iStockphoto.com/
Cory Thoman
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This unique creature looks like
a green leaf swimming along in
the sea. E. chlorotica’s favorite
meal is strands of algae, which
are green sea plants. It sucks
on each strand as if it were a
straw, slurping out its insides.
Sounds delicious, right? But it
only needs to eat one meal of
algae at the very beginning of
its life.
© iStockphoto.com/Weslye Thornberry
When a sea slug emerges from its egg, it is
surrounded by a protective shell. For a while,
it floats on top of the water. Then it settles to
the ocean floor, where it loses its protective
shell. From that point on, it must protect itself.
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© Jupiterimages Corp.
Strangely Beautiful
Elysia chlorotica
See Solar Sea Slugs on page 2
1
Solar Sea Slugs
Write About This!
Continued from page 1
A slug’s mouth is just a tiny
hole. When the slug opens
it up, rows of teeth scrape
food into tiny bits.
3
© Eye of Science/
Photo Researchers, Inc.
They’re all animals!
© 2008 Proceedings of the National
Academy of Sciences Publication
2
With their soft bodies, you’d think sea slugs would be
easy prey, but they’re not. How do they defend themselves?
Many sea slugs live on and around brightly colored coral reefs,
so their own bright colors act like camouflage. And some sea
slugs have poisonous stingers. They’re not born with them,
though. These sea slugs eat creatures that have the stingers,
like stinging jellyfish and anemones. Instead of digesting
the stingers, the stingers stick
out through their own skin. These
protruding stingers allow the sea
slug to protect itself from predators.
© Jupiterimages Corp.
© iStockphoto.com/Cathy Keifer/Keiichi Hiki/Scott McCabe
© Learning A–Z All rights reserved.
pointy protection
Some plants
look like
animals, and some
animals resemble plants.
Are these organisms
plants or animals?
This species of sea slug can use
photosynthesis because, when
it had its meal of algae, it
essentially stole some of the
algae’s genes—the components
of cells that tell the body how
to make what it needs. It
obtained the genes from a
molecule called chlorophyll.
With these chlorophyll genes
in its cells, E. chlorotica could
be considered to be a
“solar-powered” animal!
Suppose that you, like E. chlorotica, could
make your own food inside your body,
instead of eating. How would your life be
different? What would be the advantages
and disadvantages? Use your answers to
help you write a story, essay, or poem
about your new life as a planimal.
© iStockphoto.com/Zurijeta
After that, it never has to
eat again because now, like
a plant, it is powered by the
Sun. E. chlorotica can make its
own food by photosynthesis,
converting the energy in
sunlight into all the energy its
body will ever need to grow
and survive.
© iStockphoto.com/Leo Blanchette
Don’t bother
looking for
planimal in
a dictionary.
It’s not an official
word . . . yet. E. chlorotica
is a recent discovery. But
scientists believe they will
find more like it. If they
do, you could soon find
planimal in a dictionary.
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