Biofilm
Thin film of bacteria and microorganisms that covers all submerged surfaces. Natural food for shrimp, snails and fry.
Detailed explanation
The biofilm is a microscopic ecosystem that forms on every surface in the aquarium: glass, rocks, wood, leaves, plants. It is composed of bacteria, microscopic algae, protozoa and other microorganisms.
For dwarf shrimps (Neocaridina, Caridina) the biofilm is a fundamental food source. They spend hours scratching the surfaces eating the biofilm. Catappa woods and leaves are rich in biofilm.
For the fry, biofilm is the first food in the initial days, when they are too small to accept feed.
Biofilm is a sign of aquarium health. Do not try to remove it (except from the front glass for aesthetics).
Mosses and plants with finely divided leaves host more biofilm per unit area, making them ideal for shrimp aquariums.