The Snailfish

After lunch, a scientist came up from the lab. He carried a glass jar. He put it on a table in the shade.

Inside the jar was a small fish. It was very soft. It looked like a tadpole.

Polly looked closely. The fish was pale pink. It had small dark eyes. It had a worried little mouth.

"This is a snailfish," the scientist said. "We brought it up from very deep water. No fish lives deeper than this one."

Polly tilted her head. The scientist explained: water pushes very hard down there. A normal fish would break.

The snailfish has a special chemical in its body. The chemical helps it stay strong under the pressure.

"But there is a limit," he said. "Below a certain depth, no fish can live."

Polly thought about this. A line, deep in the sea. Below the line, only soft, small creatures. No fish.

The snailfish has soft skin. It has no scales. Its body cannot hold air, because the air would be crushed.

It moves slowly in the dark, waving its long body.

The scientist held the jar up to the light. The fish glowed a little. "We only discovered this fish in 2014," he said.

Polly looked at the small worried face. Far below, other snailfish were swimming quietly in the dark.