The tadpole is such a cool animal that deserves close inspection. Look how camouflaged that creature is! It blends right into the detritis and muck that yours truly is holding. This is a bullfrog tadpole and it can take up to two years to transform into a frog. But what a transformation! It becomes an entirely new creature. Its body changes, it grows legs and the tail is absorbed into the body and used as food. The eyes change from small ones located on the side to bulging ones located on top of the head. The heart changes from two-chambers to three-chambers. It loses its gills and grows lungs. Its mouth loses its tiny teeth for feeding on algae. And, its digestive tract changes so it can go from a diet of algae to one of primarily insects. Whew! That would be the equivalent to the class nerd transforming into a super model in two years. Very unlikely!
Dragonfly nymphs are another favorite of the pond exploration. It also has an "extreme makeover" story. I apologize for the blurriness of the photo, but the dang thing wouldn't stop moving! They are truly so ugly they are cute! They spend their time on the bottom of the pond feeding on small insects, fish and even tadpoles. This video shows one feeding on mosquito larvae with its lightening fast jaw. The dragonfly larvae's lower jaw or labium is hinged and folded beneath its chin. It can propel it out to grasp prey almost half the length of its body. Here is another video with a great view of the labium.
When the nymph is ready, it climbs out of the pond and go through metamorphosis. Similar to a cicada, the nymph's exoskeleton cracks open and out comes the adult dragonfly leaving behind a shell, called the exuvium. This amazing video shows it in a way I could never explain.