Semi-aquatic
lizards,
such
as
the
water
anole
(Anolis
aquaticus),
have
a
unique
ability
to
stay
submerged
for
extended
periods
by
creating
an
air
bubble
around
their
snout.
This
behaviour,
first
observed
in
2018,
has
now
been
confirmed
in
18
other
anole
species.
The
air
bubble
helps
the
lizards
breathe
while
underwater,
enabling
them
to
remain
hidden
from
predators
for
longer
durations.
Researchers
have
recently
discovered
that
this
bubble
is
not
just
a
side
effect
of
their
water-repellent
skin
but
plays
an
essential
role
in
their
survival.
Air
Bubbles
Extend
Dive
Times
In
a
study
led
by
Lindsey
Swierk,
assistant
research
professor
in
biological
sciences
at
Binghamton
University,
28
water
anoles
were
observed
to
determine
how
long
they
could
stay
underwater
with
and
without
their
air
bubble.
The
results
revealed
that
anoles
with
the
air
bubble
could
remain
submerged
32%
longer
than
those
without.
This
extra
time
underwater
helps
them
avoid
predators
in
their
natural
habitats
near
riverbanks
in
Costa
Rica
and
Panama.
How
the
Air
Bubble
Works
Water
anoles
produce
the
bubble
by
exhaling,
which
is
then
held
in
place
by
their
hydrophobic
skin.
As
they
dive,
the
bubble
expands
and
contracts,
allowing
the
lizard
to
redistribute
oxygen,
enabling
longer
dives.
The
longest
recorded
dive
for
an
unaltered
anole
during
the
study
lasted
over
five
minutes.
However,
anoles
whose
skin
was
treated
to
prevent
the
formation
of
the
bubble
had
shorter
dive
times.
Future
Research
on
Bubble
Breathing
Swierk
suggests
that
if
the
study
had
been
conducted
in
the
wild,
the
difference
in
dive
times
might
have
been
more
pronounced,
as
the
pressure
from
real
predators
could
push
the
lizards
to
stay
submerged
even
longer.
The
research
team
now
aims
to
explore
whether
the
bubbles
serve
as
a
“physical
gill,”
similar
to
how
diving
beetles
use
trapped
air
to
replenish
their
oxygen
supply.