Jupiter (and Saturn) has no solid surface, like the Earth.  Rather the
density and temperature increase with depth.  The lack of solid
surface need not be a deterrent to life, though, as many aquatic
animals (e.g., fish, jellyfish) never touch a solid surface.

There has been speculation that massive gas-bag organisms could exist
in Jupiter's atmosphere.  These organisms might be something like
jellyfish, floating upon the atmospheric currents and eating either
each other or the organic materials formed in Jupiter's atmosphere.