I would think the results would vary depending on if the study was done on a nocutral species or not.
Will fish grow faster in the dark?
- Thread starter stuckinthemiddle
- Start date
It kind of makes sense to me. But I'm talking about almost total darkness for most of the day. You would need a room with no windows. Found this about the gators:
http://www.aquanic.org/publicat/usda_rac/efs/srac/232fs.pdf
"Many different designs of growout facilities have been built. Grow-out buildings are heavily insulated concrete block, wood or metal buildings with heated foundations.
The foundation is a concrete slab laced with hot water piping or, less commonly, electric heating coils. A constant tempera-Grow-out buildings rarely contain windows, and many producers prefer no skylights. In fact, most animals are kept in near or total
darkness except at feeding and cleaning times."
http://www.aquanic.org/publicat/usda_rac/efs/srac/232fs.pdf
"Many different designs of growout facilities have been built. Grow-out buildings are heavily insulated concrete block, wood or metal buildings with heated foundations.
The foundation is a concrete slab laced with hot water piping or, less commonly, electric heating coils. A constant tempera-Grow-out buildings rarely contain windows, and many producers prefer no skylights. In fact, most animals are kept in near or total
darkness except at feeding and cleaning times."
Makes sense for catfish as most of them are nocturnal anyways.Peanut_Power;2870673; said:It would be risky to try it possibly though, as when the fish sleep their metabolism starts to slow down, which means digestion will slow as well. Might have a higher potential for bloat or other complications possibly.
I believe they DID do this study with catfish though, and they actually did grow faster. I'll have to look around and see if I can find the info, tis interesting.
It varies by fish and by the growth stage.
Catfish grow best in the dark. [1]
Tilapia, the light (photoperiod is the tech. term) significantly effects the fry. The fry grow best with the lights always on or 18on-6off. The fingerlings don't seem to care, and for broodstock, natural day cycles are reccomended. In experiments always on, 18/6off, and always off caused reduced fry counts and longer times to first brood. [3]
For trout, it makes a huge difference in fry and fingerling performance with 18/6dark being the best. [4]
That's the scientist's opinion.
My observation is that my fish take feed much more readily when the tank light is off. I think it is because they feel exposed or vulnerable when the light is on. With the light off they get roughly a 14/10dark photoperiod from the windows and ambient light in the living room.
My opinion is that "daytime" fish from clear waters do best with natural photoperiods, and nocturnal fish and fish from murky waters do best with reduced lighting.
HTH, Ellie
Sources:
[1]Growth and Survival of Fingerlings of Silver Catfish Exposed to Different Photoperiods Rosamari Piaia, Clarice R. Townsend and Bernardo Baldisserotto
[2] Effects of photoperiod on the performance of farmed Nile tilapia Oreochromis niloticus Abdel-Fattah M. El-Sayed and Mamdouh Kawanna
[3] Tilapia Culture Abdel-Fattah M. El-Sayed p44-45.
[4] Photoperiod influences growth rate and plasma insulin-like growth factor-I levels in juvenile rainbow trout, Oncorhynchus mykiss TAYLOR J. F. ; MIGAUD H. ; PORTER M. J. R. ; BROMAGE N. R.
Catfish grow best in the dark. [1]
Tilapia, the light (photoperiod is the tech. term) significantly effects the fry. The fry grow best with the lights always on or 18on-6off. The fingerlings don't seem to care, and for broodstock, natural day cycles are reccomended. In experiments always on, 18/6off, and always off caused reduced fry counts and longer times to first brood. [3]
For trout, it makes a huge difference in fry and fingerling performance with 18/6dark being the best. [4]
That's the scientist's opinion.
My observation is that my fish take feed much more readily when the tank light is off. I think it is because they feel exposed or vulnerable when the light is on. With the light off they get roughly a 14/10dark photoperiod from the windows and ambient light in the living room.
My opinion is that "daytime" fish from clear waters do best with natural photoperiods, and nocturnal fish and fish from murky waters do best with reduced lighting.
HTH, Ellie
Sources:
[1]Growth and Survival of Fingerlings of Silver Catfish Exposed to Different Photoperiods Rosamari Piaia, Clarice R. Townsend and Bernardo Baldisserotto
[2] Effects of photoperiod on the performance of farmed Nile tilapia Oreochromis niloticus Abdel-Fattah M. El-Sayed and Mamdouh Kawanna
[3] Tilapia Culture Abdel-Fattah M. El-Sayed p44-45.
[4] Photoperiod influences growth rate and plasma insulin-like growth factor-I levels in juvenile rainbow trout, Oncorhynchus mykiss TAYLOR J. F. ; MIGAUD H. ; PORTER M. J. R. ; BROMAGE N. R.
