Voynich's anatomy

[ololololo]

Why would they be standing and laying in various unidentifiable pieces while they all flow into each other and finally into another water body fully of various creatures on f79v? 

I think the author might have had a principle of depicting everything without any external hint of organs. That is, if this body of water at the bottom has any significance, it was deliberately embellished with fish and small animals. If it doesn’t matter (so that a foolish decoder would think they’re looking not at the genitourinary system, but at some kind of fountain flowing into a lake), then it could be depicted in any way at all.
That is, the author could depict everything else however he wanted in order to embellish the rest of the picture. In any case, animals don’t matter to me.