Many marine invertebrates have body surfaces that are permeable to water but not to salt. osmosis can change the pressure of their body fluids. fortunately, the ocean is very stable in its salt content. what would happen if a jellyfish were placed in a very low-salt environment such as an estuary?

When there will be a low salt environment, the jellyfish will increases the intake of water through its surface, because the solvent concentration will be low inside the jellyfish, as compared to the estuary. Thus, it will swell up and may die after bursting, as well. The environment is called as a hypotonic environment. The solute concentration is high inside jelly wish and lower in the estuary, thus, fluid diffusion will occur from fish to water body

They are all in a iving organism.