Many fish from temperate climates can survive tropical temperatures but will not thrive if they don't experience a winter cool-down. That's really the issue.
Cold water species for tropical tanks
- Thread starter MultipleTankSyndrome
- Start date
This is true. I meant species that have a natural range encompassing temperate and tropical climates (like the weather loach, or the catfish/sunfish CrazyPhishMan mentioned), therefore being able to do well in both.
I understand but some gobies simillar to sculpin can survive also in tropical tanks.But in Europe they are not allowed...
In addition to the seasonal variations that
D
dogofwar
mentioned, which are ignored by a lot of keepers, I think that consideration should be given to these supposedly optimal temperature ranges that are often quoted for fish.
Over and over we see a particular species that has a temperature range that is given, perhaps 70-80F, and keepers think that if their tank is at either of those extremes that the species will thrive perfectly. I don't think that is reasonable in most cases.
Carrying that further, we see keepers who have a fish of species A, which is quoted as having a temperature range of 75-85F, together with a fish of species B, whose range is given as 65-75F. These people seem to think that maintaining their tank at exactly 75F will provide a perfect home for both species. This sounds even less reasonable.
Assuming that the temperature ranges given are somewhat accurate...and that is a big assumption...common sense would indicate that purposely keeping the temperature at either extreme of that range is not desirable.
Over and over we see a particular species that has a temperature range that is given, perhaps 70-80F, and keepers think that if their tank is at either of those extremes that the species will thrive perfectly. I don't think that is reasonable in most cases.
Carrying that further, we see keepers who have a fish of species A, which is quoted as having a temperature range of 75-85F, together with a fish of species B, whose range is given as 65-75F. These people seem to think that maintaining their tank at exactly 75F will provide a perfect home for both species. This sounds even less reasonable.
Assuming that the temperature ranges given are somewhat accurate...and that is a big assumption...common sense would indicate that purposely keeping the temperature at either extreme of that range is not desirable.
i agree with you .But some species are about your personal experiences in care of them.It means that some species are really doing well in tropical tanks like weather loach,amerius nebulosus or stone loach...BY my experience you dont need some winter/cooler phase by these fishes....These fishes ihave had for many years in unheated tanks....Sometimes is personal experience in care of fishes better than theory...
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A couple weeks ago my gymnos etc were at 48-50 degrees. This morning they’re at 70 They’ll be on that roller coaster where it’s a couple weeks on the 50s, then a couple in the 60s back and for until April when the water gets warm. Some days in august the sirface temps will be 95-96. It gets cold they move into the shallows in the sun. It gets hot the settle down deep and find shade.
When you read over and over again in books by academics (not YouTube, not the Internet peanut gallery) references to “raising the temperature a few degrees to trigger spawning” “daily cool water changes to trigger spawning” “drop the water level and bring it back up over a period of days to trigger spawning” etc for almost every species that’s commonly spawned in captivity- what you are actually reading is that the fish need seasons. Tropical or otherwise.
the idea of setting a static temperature doesn’t make any sense to begin with. The idea of setting a static temperature and then putting a bunch of fish that are at the low end of there tolerance and a bunch of fish at the upper limit of there tolerance togetheralso Makes no sense.
You got fish whose metabolism is going hard and fish that are naturally slowing down there own food response and activitiy levels.
we can also make lists of smallest tank for such and such fish etc but anytime we as fish keepers are talking about what’s the “extreme fill in the blank” I can get away with whether it’s low temp hi temp tank size water changes stocking levels or whatever- we aren’t talking about keeping our fish optimized We are discussing compromises in the quality of their care.
When you read over and over again in books by academics (not YouTube, not the Internet peanut gallery) references to “raising the temperature a few degrees to trigger spawning” “daily cool water changes to trigger spawning” “drop the water level and bring it back up over a period of days to trigger spawning” etc for almost every species that’s commonly spawned in captivity- what you are actually reading is that the fish need seasons. Tropical or otherwise.
the idea of setting a static temperature doesn’t make any sense to begin with. The idea of setting a static temperature and then putting a bunch of fish that are at the low end of there tolerance and a bunch of fish at the upper limit of there tolerance togetheralso Makes no sense.
You got fish whose metabolism is going hard and fish that are naturally slowing down there own food response and activitiy levels.
we can also make lists of smallest tank for such and such fish etc but anytime we as fish keepers are talking about what’s the “extreme fill in the blank” I can get away with whether it’s low temp hi temp tank size water changes stocking levels or whatever- we aren’t talking about keeping our fish optimized We are discussing compromises in the quality of their care.
Agreed. The only caveat I would make is that it would require years, not weeks or months, of experience keeping a cold- or temperate-water fish species in tropical temps continually before it would be safe to call the practice successful.
Another factor to consider is breeding. I suspect that there are species that can be maintained at a constant temp higher than "ideal", but that will not come into breeding condition unless they get their seasonal temp swings. So...is keeping them for years, apparently healthy but without breeding...to be considered a success? Depends on your own interpretation.
edited to add: Aaaaand...so it happens again. Someone else, in this case
C. Breeze
, types faster and describes something faster and better than I do as I laboriously peck out a response! 
i agree with all coldwater experts.Cooler period is important.Season is important.But I forgot to say that my fishes were in unheated tank in unheated room where in winter was 15-18 degrees.So that was cooler period.ANd in summer it was about 24 degrees.and if you had a sturgeon and barbels-you cant think about breeding in no aquariums....no ponds.....so you dont must to set conditions for breeding.Agreed. The only caveat I would make is that it would require years, not weeks or months, of experience keeping a cold- or temperate-water fish species in tropical temps continually before it would be safe to call the practice successful.
Another factor to consider is breeding. I suspect that there are species that can be maintained at a constant temp higher than "ideal", but that will not come into breeding condition unless they get their seasonal temp swings. So...is keeping them for years, apparently healthy but without breeding...to be considered a success? Depends on your own interpretation.
edited to add: Aaaaand...so it happens again. Someone else, in this case
