Hey guys,

Did you know that sailfish lizards and baby iguanas can walk on water?

I'm an MIT student doing research on on walking on water. Does anyone know the leg speeds and foot sizes of these water-walking reptiles? I'd be willing to pay for all shipping costs and acknowledge you in a forthcoming publication.

Many thanks, David

Baby sailfin lizards, baby iguanas, baby basilisks, etc. may be able to run fast enough on water to appear to walk on it as they use the water tension to keep themselves up. Adult sailfin lizards cannot "walk on water." They are way too heavy. I don't know the speeds required to stay up on the water.

I'm a vet student at Tufts University, so this sort of thing interests me as well...

It's my understanding that a key feature allowing these reptiles to be able to tread water is more the overall anatomy of the foot rather than a specific length. Many iguanas and iguana relatives such as the sailfin lizard have very long toes on their hind feet which help disperse the lizard's weight on the surface of the water. A second species that also has this ability is the plumed basilisk. This species also shares the long toe characteristic. The body of basilisk is on average about 20 cm shorter than the sailfin, but when compared to other species of reptiles both are on the smaller side which is also a factor. Another key feature of both these lizards is long hind legs which give it the speed needed to tread water.

It is a great example of convergent evolution which has allowed different species from different families to develop a way to evade predation. However, many other lizards also share the long toe trait but have not adapted the ability to tread water, perhaps due to non aqueous habitats or other factors.

Keep me posted on your research, it's a fascinating topic which I'd love to know more about.

collard lizards can tread water when running on hind legs, i think they use their tail and feet when doing this thats all i know.