Tadpoles provide one of the most visually stimulating progressions in nature. Starting as eggs, these creatures hatch as fishlike animals and then gradually grow and change to become musical frogs and toads. Although all tadpoles look very similar, there are a couple of distinctions, especially between these creatures and small fish.
The first step to identifying a tadpole is differentiating it from small fish in the area. Tadpoles are fishlike in that they have tails, but that's where the similarity ends. Instead of having long fishlike bodies, tadpoles have a round body with a tail attached. They are all under an inch long at birth, and range from light green to almost black, with or without spots.
Tadpoles hatch from eggs, which are laid by frogs. Therefore, although tadpoles are aquatic, they will only be found in water that could have been easily accessed at some point by the parent frogs, who live on land. The most likely spots for tadpoles are the shallow areas of lakes and rivers, small creeks and fish ponds.
Frogs lay eggs in early spring, when the weather begins to get warmer. They lay groups of eggs that are stuck together and stuck to some stationary object, like the wall of a pond, a leaf or a rock. Tadpoles hatch within a couple of weeks, so mid-spring is the time to find, identify and collect tadpoles.
It is difficult to identify tadpoles as to what frog species they come from, but it is easy to differentiate frog tadpoles from toad tadpoles. Toads, as larger animals, produce large tadpoles, with large bodies and shorter tails. As tadpoles develop, it becomes easier to notice characteristics like colour, shape and size.
One very simple way to identify tadpoles is by observing what sort of frogs there are in the area. If there are a large number of tree frogs around, for example, any tadpoles are likely to be those of the tree frogs. The same is true of toads.