Largest water walker

The largest animal capable of walking upon the surface of water is the Indonesian giant sailfin dragon (Hydrosaurus microlophus). Native to the southern portion of the Indonesian island of Sulawesi (Celebes), living near expanses of freshwater like mangrove swamps and rivers, it frequently exceeds 1 m (3 ft 3 in) in total length, and is capable of running short distances across the water surface, using its feet and long, sturdy. dorsally-fringed tail for balance. The largest confirmed specimen on record measured 1.070 m (3 ft 6 in) – snout to vent = 0.325 m (1 ft); vent to tail tip = 0.745 m (2 ft 5 in) – but was missing its tail tip, so would have been even longer when still complete.

This is also the largest of the four sailfin dragon species (all of which are water walkers) and therefore the largest member of the entire taxonomic family of agama lizards, which also include the four basilisk species. These are more famous than the sailfin dragons for water-walking (and with which the sailfins share the specialized toe flaps that assist them in this activity), but all of them are smaller in size, growing to a total length of only 0.76 m (2 ft 6 in) in adult males (adult females are smaller).

Recently split into four species, the South American basilisk lizards (Basiliscus spp.), aka Jesus Christ lizards, can run bipedally across a water surface at a velocity of 1.5 m/s (5 ft/s) for approximately 4.5 m (14 ft 9 in) before sinking. They can also "walk on water" on all fours, which extends the distance that they can travel on the surface by about 1.3 m (4 ft 3 in). No comparable metrics have yet been obtained for the sailfin dragons' water-walking abilities.

Various small insects are also able to move across the surface of water in ponds and lakes without sinking, in particular the familiar pond skaters (family Gerridae, suborder Heteroptera).