Australia's arachnid diversity
is truly a beautiful thing, with new spiders still being discovered. This
elegant creature is among the latest, unveiled at the inaugural World Science Festival in Brisbane, Queensland on March 9,
named in honour of festival co-founder and famous physicist Brian Greene.
Dolomedes
briangreenei is a member of the water-spider genus Dolomedes, and was named
after Brain Greene because it uses miniscule vibrations on the surface of the
water, or waves, to find its prey.
"With
the announcement last month of humankind's first detection of gravitational
waves -- ripples on the surface of space and time -- I am particularly honored
to be so closely associated with a spider that has its own deep affinity for
waves," Greene said in a speech at the festival.
Like others of its kind,
Dolomedes briangreenei has a fine coat of velvety hairs, in dark brown with
white stripes on its head for the male and beige stripes for the female.
These
hairs are hydrophobic, which allows the spiders to skate across the surface of
water. They can also dive underneath the surface and swim along the bottom. Air
trapped in the spider's hairs forms a sort of fine air coat around the spider;
their abdominal lungs then breathe this air, literally
allowing the spider to breathe underwater.
The
larger members of the genus feast on large food, such as fish and frogs and
tadpoles. D. briangreenei is one such spider. To hunt, it attaches itself to
the shore with its back legs and spreads its remaining legs across the water.
From this position, it can detect find vibrations that alert it to the location
of its prey, much like a web-building spider detects vibrations in its web.
The spider can not only tell
the distance and direction of the prey, it can also detect how large it is, and
distinguish between the vibrations caused by an animal or a leaf falling into
the water. When they detect their prey, they run quickly across the water and
use small claws at the tips of their legs to capture whatever it is. They can
then paralyse their prey with venom before returning to the safety of land to
eat.
In addition to aquatic prey and
insects, D. briangreenei also preys on cane toad tadpoles, a destructive introduced
species that has wreaked havoc on Australian ecosystems and is nigh impossible
to manage. This makes D. briangreenei an impressive and useful little beastie
indeed.
And don't worry. Although
Australia seems to have a lot of animals that are venomous to humans, the
Dolomedes genus is not among them.
Isn't
she pretty?
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