Thursday, August 29, 2013

Beautiful, aberrant Barking Treefrog (Hyla gratiosa) from Lamar County

Last week, I was asked to identify a remarkable frog that a resident of Lamar County found in her garden. (see pictures below) Although this frog is uniquely hyper-melanistic and axanthic (lacking yellow pigment) in places (exposing the blue structural color), it is clearly identifiable as Hyla gratiosa by its size, shape, granular skin and dorsal pattern. Photos by Jennifer Willis of Barnesville, GA

September 9th update ... this frog (and photos) were featured in the latest GA DNR bulletin, with a quote from UGA Biologist and Professor Dr. John Maerz ...

What frog is that? Jennifer Willis of Barnesville photographed this odd-looking amphibian (left) on a green pepper in her garden Aug. 19. Although it’s a barking treefrog – common across most of the state – Dr. John Maerz of UGA’s Warnell School of Forestry and Natural Resources said the uncommon coloring is from a skin mutation. Maerz writes that amphibian skin has three cell types, called chromatophores, that make color. Xanthophores produce yellows and oranges. Below them, iridophores reflect blue. In between are melanophores, which make black. Light hitting a frog’s skin reflects blue light. But it passes through yellow xanthophores, producing green. This frog is missing xanthophores on its back; hence, the bright blue patches. The big black patch is unique: Black areas would usually be small, showing up as dots, according to Maerz.

To see the bulletin itself, click here.