Vernal ponds  fill with water during the fall and/or early spring.  Organisms that live in the ponds must complete the aquatic portion of their life cycle before the ponds dry in the summer. Many aquatic invertebrates and amphibians spend part of their lives in the ponds.
 

These are typical temporary ponds in south-central Pennsylvania. These pictures were taken in early spring.
 

Marbled salamanders, Ambystoma opacum, breed and lay their eggs in the dry pond bottom during the fall months.  Eggs hatch when they become submerged during fall rains.
  Photograghs by Dave Brotherton

Jefferson salamanders, Ambystoma jeffersonianum (on the left), and spotted salamanders, Ambystoma maculatum (on the right), arrive at temporary ponds to breed in early spring.
 

These are egg masses of the spotted salamander. Egg masses may be fairly clear, like the photo on the left, or cloudy, like the photo on the right.  Salamander egg masses are often "chewed" on by tadpoles of the wood frog, Rana sylvatica, as you can see in the photo on the right.
 

Wood frogs usually begin arriving at ponds to breed around the same time as the salamanders.  On the left, two males compete over a female frog. Wood frog eggs are shown on the right.

American toads, Bufo americanus, lay their eggs in long strings later in the spring.
 

Larval amphibians are vulnerable to a variety of prey, including adult and larval predaceous diving beetles.  The beetle larva on the right has caught a larval salamander.

Spotted turtles may live in temporary ponds. During the spring and summer months they move among ponds, eating a variety of aquatic organisms including amphibian eggs and larvae. Notice the transmitter on the back of this turtle - she is being tracked as part of a research project.