Monday, April 26, 2010

Hatchlings... (about 5 weeks)

Over the last week there have been some interesting developments with the tadpoles.  The differences in size and differentiation state have increased - the largest ones are about 70% larger than the smallest.  All seem to eat well (and more aggressively) so I think there may be some genetic variability (which suggests the wild population is diverse. (bigger images)

Most of them seem to be developing more complex bone plates, lungs, hearts, mouths and eyes.  Even the small ones seem to have substantial control of the eye position, but none appear to have iris control yet.  (bigger versions)

The biggest and most differentiated ones (perhaps 5-10% of the total) have begun to develop legs.  The small white buds that appeared a week ago have begun to change into more complex tissue and elongate near the tail. (bigger versions)

The pigments on many have begun to change as well.  Some that appear in olive and green have begun to spread and the gold flecks are becoming less dominant.  Interestingly, small snails have begun to appear over the last week - larva must have come from the original pond water.  (bigger versions)

As usual, many images from the project are here: http://tanukifu.smugmug.com/Animals/hatchlingsMarch2010