DAY 1- Creatures Blackwater

One biome the dev wanted to have in the game is an aquatic biome.
My particular idea was to have this area where the plants excrete thick substances that makes the water more viscous, and as the players dive deeper, the more viscous the water becomes. The thunderous rivers and falls in the uneven highlands pool into quieter but gigantic lakes in the second flatter level surrounding the peaks, like how a fountain contains the water gushing out of the top.

The creatures in this area resembles gigantic versions of small insect larvae and bacterias in ponds due to the higher viscosity. Water in our world, feels thicker the smaller a creature is, and they can't exactly move the same way a large fish would propel itself in water. So I figured it stands to reason that an area with thicker water would also produce larger creatures that need to propel similarly to the small organisms in our world.

I also thought of having Air sacs and bubbles as a theme in this area, with creatures and plant