Sunday, May 8, 2011

Developing Wood Frog Eggs

Finally, the wood frog eggs are starting to develop into tadpole shaped embryos.  I expect these eggs to hatch next week.

Fresh wood frog eggs are very easy to spot......
wood frog eggs masses - freshly laid
....but are harder to find as they develop. Egg masses lose their distinct shape and symbiotic algae turns them greenish, making the eggs blend in with the general pond vegetation and organic matter.
wood frog egg masses - newly hatched
close up of wood frog egg mass - freshly laid

Due to the transparent gelatin-like coating, embryo development can be followed from fertilization through hatch. The embryo (black ball at center of egg in left photo) begins to elongate and grow into tadpoles. The eggs hatch before the tadpoles are able to swim, so they remain in or on the egg masses for several days (see below).
close up of newly hatched wood frog tadpoles

Wood frog eggs hatch 4 to 28 days after being laid.  Embryonic development is temperature dependent, so timing of hatch varies with weather conditions. 

No comments:

Post a Comment