IMAGES have been released showing children petting a group of dolphins at a Californian swimming pool.

On first viewing they look like the kind of marine creatures that may jump through hoops and perform acrobatics, but look a bit closer and you may notice something a little bit different.

Images show children petting dolphins in a swimming pool

But can you spot what’s different about them?

Posted online by the activist PETA organisation at the John C. Argue Swim Stadium, Los Angeles, these dolphins are actually robots, designed to replace animals held captive at marine parks.

As the brain-child of a group of New Zealand entrepreneurs, the ultra-realistic animatronics can behave like the real thing and can swim under water without intervention.

The electrical dolphin, which costs a whopping $20.8m each, weighs around 250kg, is 2.5m and has skin made from medical-grade silicone.

It’s hoped that that the life-like animatronics could one day entertain crowds at theme parks, instead of wild animals held in captivity.

Speaking ahead of an exclusive one day test event of the Delle model, PETA suggested that the new technology will “allow humans to get to know these highly intelligent mammals without confining them to barren concrete tanks.”

The dolphins are actually animatronics made out medical-grade silicone

Used in Hollywood movies, they cost £20.8m each

It is hoped that they could end animal captivity

Some 20 European countries have already banned or limited the presence of wild animals in circuses.

PETA activists Katherine Sullivan added: “There is an end in sight to cruel ‘swim with dolphins’ programs, for which young dolphins are traumatically abducted from their ocean homes and frantic mothers, sometimes illegally.”

The Dolphin product, was designed and created by technology designers Edge Productions.

Their CEO, Walti Conti, now believes that the animatronics may bring back audiences turned off by parks using live animals.

He said: “There are like 3,000 dolphins currently in captivity being used to generate several billions of dollars, so there’s obviously an appetite to love and learn about dolphins.”

“We want to use that appetite and offer a kind of different ways to fall in love with the dolphin.”

They company have already made the aquatic creatures for use in Hollywood blockbusters such as Free Willy, Deep Blue Sea and Anaconda.

Speaking at a pilot event last year, creative director for Edge’s animatronic program, Roger Holzberg, said: “The idea of this is to really to create a kind of Sesame Street under water.”

“Those characters taught a generation how to feel about different kinds of aspects of humankind in ways that had never been imagined before. And that’s what we dream of with this project.”