The European mudminnow lives for up to five years (1), becoming sexually mature within the first year of life (1) (2). Spawning, where the female releases yellowish-orange, sticky eggs into the water, takes place in March and April. The female selects a suitable nest site, either a spot over roots or watermoss, or a nest made of plant material in a depression at the bottom, and releases six to eight eggs at a time, which are then fertilised by one or more males. This process is repeated multiple times, with the female usually depositing a total of up to 200 eggs. After spawning, the female aggressively guards the eggs until hatching (2) (3) (6).
The newly hatched larvae initially rest at the bottom or attached to various objects, and remain largely motionless except for their waving pectoral fins (3). About a week after the eggs have hatched, the young European mudminnows begin moving around and feeding on live food (2), such as tiny crustaceans. At the end of the first summer, they start eating larger food items (3). The European mudminnow is known to feed primarily on animals found at the water’s bottom, such as small shrimps and snails, although beetles and other insects are also sometimes taken from mid-water or the surface (3).
The mudminnow can survive in extremely low oxygen conditions due to its ability to use its swimbladder for air breathing (2) (3), and can reportedly survive for more than two days in the winter without water (3).