Marine Iguanas, the Only Ocean-Swimming Lizards, Explained
September 8, 2018 – Found only in the Galapagos Islands, it's thought that marine iguanas evolved from South American land-dwelling iguanas that drifted out to sea millions of years ago on rafts of vegetation or debris.
They may look menacing with their spiky spines and razor-sharp claws, but instead of meat, these iguanas love to chomp on algae underwater. Marine iguanas scrape the algae from rocks with the help of their short snouts and sharp teeth. Long, flattened tails are well-adapted for swimming through the water, much like crocodiles.
While Charles Darwin may have described their appearance as “hideous-looking,” as the only ocean-swimming lizard species in the world, the unusual features of these iguanas are beautiful in terms of evolutionary survival.
Transcript
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NARRATOR: These curvy
claws belong to the species
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we celebrate on
Iguana Awareness Day--
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the iguana.
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This green iguana
is quite common
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and even considered a
pest in some countries,
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but there are 43 other types,
more than half of which
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are endangered or vulnerable.
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One such vulnerable
species lives
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only on the Galapagos Islands.
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Found throughout
the archipelago,
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it's thought that marine iguanas
evolved from South American
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land-dwelling
iguanas that drifted
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out to sea millions
of years ago on rafts
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of vegetation or debris.
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They may look menacing
with their spiky spines
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and razor-sharp claws,
but instead of meat,
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these iguanas love to
chomp on algae underwater.
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Marine iguanas scrape
the algae from rocks
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with the help of their short
snouts and sharp teeth.
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Long, flattened tails are
well-adapted for swimming
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through the water,
much like crocodiles.
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And those razor-sharp claws?
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They're used for
clinging to rocks,
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both underwater in heavy
currents and back on shore.
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After submerged
for up to an hour
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in the often frigid
water of the Galapagos,
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marine iguanas must
warm themselves
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on land, their dark
coloration helping
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to absorb heat from the sun.
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Though it appears as
light skin coloration,
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the white wig marine iguanas
often wear is actually
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an incrustation of
salt. This distinct look
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comes from expelling excess
salt through a special gland
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near their nostrils.
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While Charles Darwin may have
described their appearance as
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hideous looking and
most disgusting,
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as the only ocean-swimming
lizard species in the world,
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the unusual features
of these iguanas
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are beautiful in terms
of evolutionary survival.
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From the tree-dwelling green
to the semi-aquatic marine,
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today we celebrate all
of the incredibly adapted
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iguana species that hold a vital
and unique place in our world.