MadSci Network: Zoology |
The slug turns into "ooze" because a "diffusional gradient" (concentration difference) exsists between the liquid inside the slug and the salt outside of the slug. In most natural processes when a diffusional gradient is present, the solution seeks a state of equilibrium, meaning that the concentrations on the inside and the outside should be the same. The concentration of salt inside the slug is much less than the concentration of the pure salt on the outside of the slug. The cell membranes of the slug are designed to keep the nutrients and minerals inside but can pass water through the membranes. So the water inside of the slug passes through the cell membranes of the slug and tries to dilute the salt concentration on the outside of the slug. The movement of the water from the inside of the slug to the outside dehydrates the slug and the dehydration turns the slug into ooze.
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