Light Hours And Spawning

Can too many hours of light prevent a fish from spawning? I noticed my male longear hasn't been digging any pits, even though he's in full breeding-dress. Then I noticed that the light on the tank wasn't turning off, so I looked at the timer, and the switch was set to "on" instead of "timer". I normally don't stay up until the light goes off, so I haven't noticed, plus the tank is in our basement, so no one could've noticed it stayed on. Guess it's a good thing I went down there.

I'm not sure about how too much light would effect them but I know that temperature and if any females are around both play a role in their nest building behavior. They like it very warm to spawn, high 70's and if it is in your basement I doubt the temperature is reaching the 75-78 range. Also if you just have a male and no female he may not do much.

I'm not sure about how too much light would effect them but I know that temperature and if any females are around both play a role in their nest building behavior. They like it very warm to spawn, high 70's and if it is in your basement I doubt the temperature is reaching the 75-78 range. Also if you just have a male and no female he may not do much.

Oh, ok. Well, it actually stays pretty warm down there, because we used to keep a lot of tropicals so we had the heat going down there. More like 71-72 though, not 75+. Is that the temp they need to spawn?

My lights are on timers, around 14 hours a day.

Temps in my tanks run from 70 to 84. Floor level to top rack level gradient.

Best temps I have seen for successful breeding ( versus just nest building but no ripening receptive females) is on the very low end 74, 76 to 78 Ideal to get them cranking. Warmer and the activity sometimes slows since they are more worried about getting enough food. If you can get them enough food on that top range they should spawn every two weeks, maybe more depending on species. Laying eggs right over the top of fry in the nest, or making two nests side by side.

That may seem warm, but most sunfish spawn in shallow water, in sun lit areas. That water warms quickly in spring, and stays warm. It is amazing how warm water that is shallow with the right bottom type gets on the north side of a body of water if its getting enough sunlight. In part of my river pond, the one shore with rocks along it that is shallow out three foot from shoreline will get to the mid seventies during the day, even if air temps barely approach fifty. So long as the sun is strong all day. Of course at those air temps the water drops down considerably at night.

My other suspicion that the warmer water is needed is the fish seem to shut down after long cloudy periods even if the water stays near 70 which seems warmish when you think about it. I think its not good for eggs to hatch or fry to develop or something along those lines. I have seen my fish abandon nests when that happens. Not sure if the eggs or fry died already, or they just give up to save energy for better times. This is all a guess, I have not done anything to document it.

Just thought it lent creedence to the reasoning that the sunfish like to spawn in the warmer temps that smbass mentioned.