Lake trout
There are three subspecies of lake trout. There is the common lake trout ("Salvelinus namaycush namaycush"), the siscowet lake trout ("Salvelinus namaycush siscowet"), and the less common rush lake trout ("Salvelinus namaycush huronicus"). Some lakes do not have pelagic forage fish during the period of summer stratification. In these lakes, lake trout take on a life history known as planktivory. Lake trout in planktivorous populations are highly abundant, grow very slowly and mature at relatively small sizes. In those lakes that do contain deep-water forage, lake trout become piscivorous. Piscivorous lake trout grow much more quickly, mature at a larger size and are less abundant. Notwithstanding differences in abundance, the density of biomass of lake trout is fairly consistent in similar lakes, regardless of whether the lake trout populations they contain are planktivorous or piscivorous.