Jellyfishes are
‘‘smarter’’ than we think
Brainless jellyfishes – with only
a loose network of nerves, called
a nerve net – respond to changes
in their environment with
surprisingly complex behaviours.
A series of studies show that a
jellyfish’s nervous system, and
its responses to the environment,
are much more sophisticated
than most us think.
This Caribbean box jellyfish (Tripedalia
cystophora) has some of the most
sophisticated eyes of the jellyfish
Each cluster (rhopalium)
world. This active hunter stalks its prey
has an upper lens, a lower lens,
with four clusters of 24 eyes.
a pair of pit eyes and a pair of
slit eyes.
Er
anDr. D
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ic N
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Dr. An
ders Garm
Dr. Anders Garm, picks up a
study subject – a box jellyfish –
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Dr. Anders Garm from the University of
Copenhagen studies how the Caribbean box
jellyfish (Tripedalia cystophora) uses its four
clusters of 24 eyes to get around.
Dr. Garm has found that the box jellyfish uses
its ability to see light and dark to find mangrove
canopies. This visual cue helps it stay in mangrove
swamps where swarms of tiny animals called
copepods – its prey – hang out.
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el
Bi
Box jellyfishes use 24 eyes to
find their “restaurant”.
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It also uses its eyes to avoid an obstacle course
of mangrove roots overgrown with all kinds of
animals that can snag and tear its fragile bell
and tentacles.
His work shows that despite not having a
conventional brain, the box jellyfish is able to
perform sophisticated behaviours, such as
navigating using sight.
near the mangrove swamps
of Puerto Rico.