Control of lake trout reproduction: role of lipids

Somatic lipid density of lake trout decreased during summer and increased after spawning in October, peaking April, prior to ovarian recrudescence. Non-lipid density increased from June or July until August and remained relatively constant until March. All lake trout ( n =30) reared on high ( n =10, 0·4%), medium ( n =10, 0·15%) and low ( n =10, 0·05%) rations from March to September spawned. In a second experiment for which the treatments commenced in November, the proportion of females maturing in the following October (high=88%, medium=69%, low=28%) was positively related to ration levels.