Ecological groups of fish according to the substrate on which they spawn

The article deals with the reproduction of fish. Fish reproduce at different ages. Reproduction occurs at different times in the life of fish. Most fish reproduce by spawning. The spawning conditions of fish are very different. The eggs are fermented in water. Depending on the choice of spawning substrate, fish are divided into 5 ecological groups. Key words: Kura, ecology, caviar, Acipenseriformes, Clupeonella