Grey mullet

The mullets or grey mullets are a family of ray-finned fish found worldwide in coastal temperate and tropical waters, and some species in fresh water. Mullets have served as an important source of food in Mediterranean Europe since Roman times. The family includes about 78 species in 26 genera. Mullets are distinguished by the presence of two separate dorsal fins, small triangular mouths, and the absence of a lateral line organ. They feed on detritus, and most species have unusually muscular stomachs and a complex pharynx to help in digestion.

Source: Wikipedia