The characteristics of fish satellite cells in situ and in vitro are described. The in situ proliferation of satellite cells appears to be very low and therefore not easy to quantify. Differences in the in vitro proliferation capacities of satellite cells have been observed between species, but a large part of these differences could be related to methodology. Most studies on fish satellite cells have been carried out on cyprinids and salmonids. The relationship between proliferation capacity and muscle growth is discussed in these fish. The differentiation of fish satellite cells is partially similar to that of myobJasts. However, there is a great heterogeneity in satellite cell differentiation that needs to be characterized.