Grasp of a Gecko

What am I looking at?

This is a glimpse into the inner workings of the foot of an embryonic Madagascar giant day gecko. You can see the bones and cartilage in red and yellow (1), the nerves in blue and green (2), and the blood cells in yellow (3). The skin is outlined in brown and orange (4).

Biology in the background

Geckos are lizards that live throughout warmer climates of the world. They are expert hunters and mainly eat insects. However, being relatively small, they are also fairly low on the food chain and so must take care to avoid being eaten by larger predators.

One of the main adaptations that allows them hunt effectively and to avoid being hunted themselves is their padded feet. Geckos’ toes are wider than those of other lizards, and their undersides are covered with millions of hairlike structures called setae. These features enable their toes to stick to any surface, wet or dry, rough or smooth, under nearly any conditions. Geckos’ toes have another unique ability – they can unstick them by bending them up and backward, allowing them to climb on almost any surface. This enhanced mobility means they can position themselves optimally for hunting or hiding, depending on whether they’re the predator or the prey.

This embryonic foot is about 3 millimeters long, or roughly six times smaller than a human thumbnail.

Technique

This image was created using fluorescence microscopy.