Snails: Algae Managers
These small mollusks consume algae and detritus in aquatic systems, supporting nutrient recycling. A single snail clears 10-20 square centimeters of algae daily, maintaining water clarity for plants and fish. Their small size (5mm) minimizes resource requirements while still performing valuable ecosystem services. Special bioreactors with calcium supplements would be needed to ensure proper shell development in calcium-poor Martian environments.