The Nikon MicroscopyU confocal microscopy image gallery was created with a PCM-2000 confocal scanning system interfaced to a Nikon Eclipse E600 upright microscope. Images were recorded in successive z-axis serial sections with C-Imaging Systems software with excitation illumination provided by an argon-ion and/or a helium-neon laser.

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View a lower magnification confocal sequence of frog stomach.

After outliving dinosaurs, frogs have changed very little from their ancestors who roamed the earth 150 million years ago. These slippery creatures can be found atop freshwater lily pads, among the canopies of tropical rainforests, burrowed deep into the sands of the Australian desert, or even hibernating in Arctic soil.

Although tireless hunters of insects, Frogs themselves are very edible and must evade many predators. In order to protect themselves, many of these small creatures secrete sticky, noxious tasting or smelly mucus. The skins of some frogs even produce poisonous toxins. Used to coat the tips of blowpipe darts and arrowheads, these lethal secretions are prized by Central and South American Indians. Scientists are also investigating toxins that are produced by the poison-arrow frog and hope to discover new treatments that can cure human illnesses.

The secret of survival for these small creatures may be due in part to their specialized permeable skin. However, researchers are becoming growingly concerned that many environmental toxins such as pesticides and chemicals also seep into the skin of embryos, tadpoles, and adult frogs.