I was fishing a warm water lake made possible by a local power plant this weekend and noticed something interesting.  4 of the 12 catfish we caught had eggs in them while none of the other species did (crappie, redear sunfish, LMB).  Granted we only caught 3 Crappie, 1 redear, and 1 Largemouth so there wasn't a big population to study.

Which leads me to this question, do fish spawn year round in warm water lakes or did something set these catfish off making them spawn early?  I know the spawn is early in this lake but Mid-January with full sacks of eggs?  And why only the catfish, unless we just happened to catch all males of the other species?

Eggs are formed months in advance. You must have caught all males of the other fish because even in cold water lakes around here, fish already have egg sacs in them. 

The fish spawn about a month earlier in the power plant lakes I fish, but the weather still has to be warming and fairly stable. 

Lesson learned.  Thank you!

Spawning tends to relate to amount of light hours per day as well. Not always temperature driven.