Oocyte Development and Induced Spawning of Smallmouth Bass (Micropterus dolomieui) in Response to Photoperiod and Temperature Manipulation: Preliminary Results

Abstract Smallmouth bass (Micropierus dolomieui) in Quebec spawn between the end of May and mid‐June. Wild broodstock (4 to 8 years old) and laboratory‐reared ones (0+ years old) reared in a water recycling system were submitted to different temperature and photoperiod regimes to extend their natural spawning period. Oocyte maturation followed in vivo showed that oocytes developed to stage III in both cases but final maturation and ovulation was limited to the laboratory‐reared bass and this, a month before the normal spawning period, at 20.5 cm TL. Exogenous factors are examined, specifically duration of long photoperiod and vital space related to non‐spawning of wild broodstock.