The fluid similar to seawater that surrounds and bathes all body cells is called interstitial fluid.

Here's why:

* Composition: Interstitial fluid is a fluid found in the spaces between cells (interstitial spaces). It's similar to seawater in that it contains salts, ions, and other dissolved substances.

* Function: Interstitial fluid acts as a medium for transporting nutrients, oxygen, and waste products between blood capillaries and cells. It also helps regulate cell volume and maintain a stable environment for cells.

* Evolutionary Link: The similarity between interstitial fluid and seawater is a strong indicator of the evolutionary origins of life in the oceans.

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