The objective of this work is the description of some biological characteristics of three bony fish caught on the coast of Mostaganem. The targeted species are: the sardine Sardina pilchardus (Walbaum 1792), the round sardinella Sardinella aurita (Valencienne, 1847) and the bonito Sarda sarda (Bloch, 1793), which are very abundant and frequent species on the west Algerian coast. Considering that the state of knowledge on the biology of these targeted species has remained fragmentary and old, our work will serve to enrich and update the knowledge that will serve as a basis for the study of the population dynamics and the evaluation of stocks.