Model frogs

Posted on February 8, 2015 by Andrew Gray

Fringed Leaf Frog, Manchester Museum

Research being conducting with our collection is helping us understand such things as water loss and temperature regulation in amphibians, and in the case of leaf frogs, heat load transfer due to their ability to reflect infra-red light. Leaf-sitting, sun-loving frogs are highly adapted, reflecting light at a wavelength not so far seen in any other type of creature, or amphibian for that matter. It’s seen only in the very leaves they sit on.

Some species have even evolved incredibly extensive flanges and unusual flaps of skin to extend their surface areas, which, when the frogs are sleeping, acts as a dermal covering to support an increase in body temperature control and also enhance their highly cryptic camouflage when sleeping. These leaf frogs belong to the genus Cruziohyla, which consists of 2 species, The Fringed Leaf Frog, Cruziohyla craspedopus, and the Splendid Leaf Frog, Cruziohyla calcarifer.

01-3&4 Cruziohyla craspedopus (sub-adult, paper) (2)[1] copy

Fringed Leaf Frog 3D model (c) Francisco Herrerias-Azcue

Collaborative research with our Photon Science Institute has allowed us to investigate many aspects of the frog’s biology, and that we maintain these rare frogs in the collection provides some wonderful opportunities for non-invasive studies.

At the moment I am co-supervising an excellent student, Francisco, from Mexico, who is making great headway investigating aspects associated with the dorsal surface area of the frogs. He is accurately mapping the area concerned through the development of a revolutionary 3D modelling technique, using a completely new way of evaluating their morphology and physiological parameters.

01-3&4 Cruziohyla craspedopus (sub-adult, paper) (1)[2] copy

Fringed Leaf Frog 3D model (c) Francisco Herrerias-Azcue

This week or so has been particularly interesting, as while filming the frogs in question from all angles on a turntable, to facilitate the 3D modelling, we were surprised how the animals maintained focus on one object in their view…

so much so that even when they’re body was turned they just couldn’t help but keep staring in that same direction – it made for some quite difficult but very amusing filming!