Jelly-fish like creatures surprise beachgoers by washing up on shore by the hundred

The Valella valellas became stranded along the Californian coastline

A by-the-wind-sailor, or Velella, jellyfish lies on the beach in Newport Beach, Calif. on Thursday, Aug. 21, 2014. The creatures, harmless to humans, have been washing up on shore in Southern California since the beginning of the week. (AP)

Thousands of small jelly-fish like creatures have been washing up on shore up and down the Californian coast line this week, carried by the warm currents and the creatures’ sail-like fins catching the wind.

The Valella valellas, more commonly known as ‘by-the-wind-sailors’ or ‘sailor-jellies’, have been intriguing beachgoers by turning up in their droves.

The creatures are around six centimetres wide and clear, but they are attached to blue floats that look like shells, which sit flat and allow the sailor-jellies to travel across the water.

They have been turning up at Redondo beach, Manhattan beach, San Pedro beach, Cabrillo and Newport beach in California since Monday.

“There were a lot of them and they were everywhere,” Juan Carlos, who paddleboards in the area, told The Daily Breeze.

“They look like the Portuguese man o’ war but they have a beautiful blue colour,” he added.

The man o’ war is about to deliver a painful sting to humans, but the Valella valella is not known for causing a sting.

Valella valellas have several tiny tentacles that they use to capture small fish, and are known to live in large groups and are routinely washed ashore in large numbers when the currents and winds carry them ashore.