All photographs copyright (2003-2013) by Kris H. Light

<strong>Water Flea</strong> at 40X magnification
<em>Scapholeberis</em> spp. / Order: Cladocera

This tiny, transparent, freshwater creature was photographed with a projection microscope, the image is projected on the tabletop onto a piece of white ...
Water Flea at 40X magnification
Scapholeberis spp. / Order: Cladocera

This tiny, transparent, freshwater creature was photographed with a projection microscope, the image is projected on the tabletop onto a piece of white paper. These animals can be pinpoint-sized to the size of a pinhead. They are very common in freshwater lakes and ponds, in fact, if you have ever been swimming or water skiing in a lake, you've probably swallowed a few of them!
The large black spot on the head is a compound eye and the long brown strip in the middle is the digestive system.
I enjoy telling my students about the reproductive cycle of water fleas. Most of the year the animals are all females. They reproduce by cloning themselves, no males needed! The olive-green oval in this waterflea's brood pouch is her developing clone. When conditions get stressful in the habitat, males can be produced; when a male and female mate, a resting egg develops. The egg is released and settles to the bottom of the lake or pond, when conditions improve, the young water flea will hatch.
Water fleas are the aquatic equalivalent of the "canary in the coal mine". Water treatment plants often use water fleas to test the quality of water before returning it to the river.

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