Fish are known to depend on water as their habitat. In fact, in the absence of water, these creatures might die. However, a new study has revealed that some fish are evolving to survive on land.

According to scientists at UNSW and the Australian National University, some species of fish have learned to live outside their usual habitat in a bid to stay safe and escape predators.

"Avoiding predators might be an explanation of why some animals move from their ancestral homes into starkly different environments, but evidence for this is rare because it is difficult to collect," says researcher Dr. Terry Ord of UNSW Sydney in a press release.

According to ZME Science, about 400 million years ago, prehistoric fish started moving away from the oceans and onto the land. The study, published in The American Naturalist, claims the same is happening today.

The researchers came across four separate species of marine blenny fish on the South Pacific island Rarotonga, which showed that they are developing their "amphibious side" -- the ability to venture on land.

Science Alert noted that the researchers watched the tropical fish closely to find out the factors that have pushed them outside the waters.

They have noticed that they would swim in coastal rock pools at low tide, but move further up on land when the tide was high. Upon looking at the density of their predators during low tide and high tide, they found out that predator danger is greater during high tide.

How about birds that may feed on the blennies ashore?

Apparently, blennies think that underwater predators are more dangerous than birds. To prove this, the researchers made fake blennies and scattered them on both underwater and ashore. Their experiment showed that more fake blennies were harmed underwater than those on the rocks.

"There were far more attacks on the model fish from predators in the ocean than predators on the shore, showing there are obvious benefits for blennies in becoming fish out of water and colonising the land," says Dr Ord.

Meanwhile, aside from escaping predators, Gizmodo cites that there are other compelling reasons why fish shift to amphibious lifestyle. This includes to find new sources of food, escape competition for resources, or escape adverse fluctuations in water conditions.