According to the materials of 2000–2004, in littoral of the gulf Arguin (at the coast of Northern Africa) dwell 91 fish species. Fish young, accumulating 97.9–99.7% of ichthyofauna, endure main cycle of development in the zone of littoral, use it for pasture and as a shelter. Five types of littoral are distinguished in the gulf. Ichthyofauna composition of different littoral types has significant similarity, but differs essentially from ichthyofauna of open ocean littoral. The role of the gulf Arguin, taking into consideration its dimensions, is unique in reproduction, biodiversity maintenance and existence of numerous fish species (including fishery species) of Northern Africa.