This week's topic is feet - which made me think immediately about mudskippers.
Mudskippers [also known as mudhoppers] are amphibious fish in the Gobiidae family who live in brackish water in mangrove swamps.
Mudskippers don't exactly have feet since they are fish ; though they can walk , jump , run and limb trees.
They use their modified pectoral fins as their feet and legs and can move fairly quickly on land -though their 'walk' is more like a series of small jumps or like someone using crutches.
They climb trees using their pelvic fins like a sucker while the pectoral fins grab the branch and pull themselves up.
They use their gills to breathe when under water . On land, they can breathe through their skin and the lining of the mouth [when its skin is wet] but they rely mainly on special water storage pouches which allow their gills to continue to collect oxygen. When there is no more oxygen in the stored water, the fish will refill the water pouches.
The need to keep the skin and eyes moist and fill up the gill pouches regularly with water means that the mudskippers don't stray far inland.
Having their eyes on top of their heads gives them an enormous field of view and these eyes can see in colour on land and black and white under water.
They can also see above and below water at the same time using their eyes something like a submarine's periscope.
This is obviously useful in avoiding predators [snakes and birds] and also catching prey [insects, crabs, prawns- though some species feed on algae.]