Floating fish take over at Philippe Parreno's Tate Modern show

The lights, sounds and moving elements are controlled by micro-organisms in a 'bio reactor'

Visitors to Tate Modern over the next six months might feel like they have stepped into a giant aquarium.

French artist Philippe Parreno's new work - Anywhen - is the latest large-scale commission in the museum's Turbine Hall.

He describes the work as an ever-changing experience "that plays with time and space".

A shoal of helium-filled fish float about the cavernous space to a surreal soundtrack from overhead speakers.

Some of the sounds are piped in live from microphones outside Tate Modern - which raises the prospect of a busker on the South Bank being heard inside the hall.

Visitors are invited to lie flat on the carpeted floor and watch as horizontal and vertical panels fall and rise over their heads.

Meanwhile, a giant moving video screen shows a film that features underwater creatures and an appearance from stage ventriloquist Nina Conti.

Visitors will also see a film as well as floating fish

What makes the whole experience even more unusual is that the sequence of lights, sounds and moving elements are controlled by a colony of micro-organisms in a "bio reactor" in the far corner of the Turbine Hall.

Unveiling his commission on Monday, Parreno said the aquatic theme had been the first idea that had come to him.

"The fish can point your attention to different parts of the architecture," he explained.

Philippe Parreno's works have often explored the borders between reality and fiction

Parreno likened his artwork to a walk in a park, where the public enter from many different levels and directions and encounter things that appear and disappear over time.

Anywhen, which runs until 2 April 2017, is the first commission to respond to the Turbine Hall's new position at the centre of the museum following the opening of the new Tate Modern extension earlier this year.

It is the latest in a long line of Turbine Hall commissions that include Ai Weiwei's porcelain sunflower seeds, Doris Salcedo's crack in the floor and Olafur Eliasson's giant yellow artificial sun.