The European bitterling (Rhodeus amarus) is a temperate freshwater fish belonging to the subfamily Acheilognathinae of the family Cyprinidae.

It feeds mainly on plants, and to a lesser extent, upon worms, crustaceans, and insect larvae.

If the woman was pregnant, the hormones in the urine would cause the fish's ovipositors to protrude.

[2] The fish spawns in clear, slow-running or still water, often with a muddy bottom.

The male sheds his sperm into the inhalent current of the respiring mussel and thereby fertilizes the eggs.