Backswimmer or water boatmen
Water boatmen are aquatic bugs that have theire
hindlegs adapted as paddles for swimming.
They stick to the surface and hunt by using
theire great red compound eyes to scan for
movement: fishes, insects and fingers!
As you might already have guessed they
swim on their backs. They are also
Backswimmers are really good flyers that can
fly long distances to another pond. So they
have wings and can leap out of the water
and take flight. But on the land they are helpless.
Backswimmer in the pond
Backswimmers can get abundant in a pond or
swimmingpool, and are hard to control.
Lucky this problem can be easy solved the
biological way: buy a pumpkinseed sunfish
(Lepomis gibbosus) or "pond perch",
"common sunfish", "punkys", and "sunny".
They are fond on backswimmers and eat them all!
But buy only buy one, not two, as they don't
have any problem in producing offspring.
Backswimmer or water boatmen in the pool
Backswimmers do bite. The easiest way to
get rid of backswimmers is to add cholorine
to youre swimming pool: use a level of 4 ppm
or even more for two weeks:
The backswimmers will feel unhappy, fly away
and have a great time in youre neighbours pool.
Lesser and greater water boatman
Altough they have an almost simular name and
appearance, they are not related.
The lesser waterboatman swim on its fronts.
The lesser waterboatman is herbivores and
lives mainly on the bottom of the pond,
and is brown or golden in color.
The greater waterboatman or backswimmer
sticks to the surface and have a
the air bubble of the backswimmer
Like the atmosphere, the bubble contains primarily
both oxygen and nitrogen, the oxygen is used and
transformed in carbondioxide that dissolves in
the water. So the nitrogen ratio in the air bubble
will increase, pushing the nitrogen to dissolve
in the water by diffusion. But there will also
be as little oxygen from the water that will
diffuse into the airbubble, the airbubble will
act as a physical gill.
In the end, this process will shrink the
airbubble and forces the water boatmen to
return to the surface.
This explains why the air bubble
becomes smaller, but also why backswimmers needs
oxygenrich water. There has been scientific
research done by Roger Seymour of the University
of Adelaide in South Africa and Stefan Hetz
from Humboldt University in Germany,
who measured oxygen in the air bubble of diving spiders.