Dive Pacific Iss 171 Oct- Nov 2019

Provided by ABC
SOUNDINGS
INTERNATIONAL NEWS
Newly discovered electric eel has the most
powerful shock
After years thinking there was
only the one species in the
genus Electrophorus, researchers
now characterise the electric eel,
Electrophorus electricus, as three
species. And a recent addition,
Electrophorus voltaic, has been
recorded generating 860 volts,
far above the previous record of
650 volts, reports ABC Science in
Australia.
E.voltai is now thought to be
the most powerful electricity
generating animal in the world, say
the authors of a report in Nature
Communications. Their research
aims to identify and describe the
electric fishes of the Amazon
rainforest, said zoologist and lead
author of the paper Dr David de
Santana of the Smithsonian’s
National Museum of Natural
History.
Though their discharge is high
voltage its low amperage and
wouldn’t necessarily be dangerous
to humans.
The electric eel is not actually an
eel at all but a type of knifefish
that grow up to 2.5 metres in
length. It was first described by
Swedish scientist Carl Linnaeus in
1766.
Electric
Electric fishes are said to be
electrogenic (produces electricity)
as opposed to others described as
electroreceptic, or able to detect
electric fields, with some species
both. Other electric fish include
electric rays and electric catfish.
Electrophorus voltai has the most powerful electric discharge
of any known animal. (Supplied: L. Sousa)
Dr de Santana and his colleagues
collected 107 electric eel specimens
over six years from across the
Amazon basin. Though they look
very similar, differences in their
DNA showed they were made up of
three different species with each of
the species living in different parts
of the Amazon basin.
“The discovery
of hidden
species diversity
and of such an
eye-catching
and long-known
organism as
electric eels
indicates that
an enormous
amount of
species are still
waiting to be
discovered in
the Amazon
rainforest,”
Dr de Santana
said. “Many
may harbour cures for diseases or
inspire technological
innovations,
reinforcing the critical
need to protect
Earth’s hotspots of
biodiversity.”
Electric fish use three
electric organs to
generate electricity
made of modified
muscle cells called
electrocytes which
can produce strong
electrical discharges
as well as weaker ones,
and they typically
use them arranged like
batteries in series fired
by entire-body muscle contractions
caused by the direct stimulation of
spinal motor neurons.
The ancient Egyptians, Greeks and
Romans all used electric fish for
their medicine to numb people
or treat conditions like gout and
headache.
Dr de Santana said electric eels
inspired the design of Italian
physicist Alessandro Volta’s first
electric battery, and an enzyme
extracted from their electric
organs has been used as a target
for drugs to treat Alzheimer’s
disease.
More recently electrical eels have
promoted the advance of hydrogel
batteries (made of a substance
similar to gelatin) that might be
used to power medical implants.
An electric ray residing in Sydney
Harbour called the coffin ray
(Hypnos monopterygius) can grow
to 40 cm. Biomedical engineer
Professor Alistair McEwan of the
University of Sydney said they use
electrical sensing like a shark to
see around them, not just passively
by listening into the electricity,
but also by sending out their own
electric field to map the world
around them”.
Researchers have looked at how
to emulate this system to monitor
internal cardiac surgery, and in
the brain. Professor McEwan and
his colleagues are also looking
at how they might be able to use
Sydney Harbour’s coffin ray
(Hypnos monopterygius)
the electroreception abilities
of Australia’s platypus and the
echidna.
“We thought the electroreception
would only work well with water.
It’s amazing the platypus works
well in fresh water without
conductive salt, but even more
amazing that the echidna can
electrically sense in the dry
desert,” he said.
Provided by ABC
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