19 replies to this topic

[Joshaeus]

Hello all! Here's a question...can most fish from the southern part of the country (Florida, Georgia, etc) handle temps in the 80's reasonably well? I tried looking this up but couldn't find it. Thanks

[Michael Wolfe]

"most fish", no... there are lots of minnows and such that never see those water temps even when the sir temp is over 100.

 

I caught Chattahoochee Sculpin and it was nasty hot in the summer time in middle Georgia... but the water coming out of the ground was a cool/cold spring in the shade.

 

Similarly, even yellowfin shiners are not that hardy with regard to water temp... they go deep or go to shady spots, etc.

 

The only fish that can tolerate those temps are the ones that live in those shallow, non flowing habitats... no based on latitude so much.

[Dustin]

Agree with Michael.  Fish like pygmy sunfishes and Heterandria would likely do fine at those temps.  I routinely catch Elassoma evergladei in less than 2 inches of water in the summer when the temps are well above 80 degrees.

[littlen]

My 2 cents are that 'handle' is a vague term.  Live in 80+ for a long duration/all year?  Not advisable.  For shorter periods (maybe +/-  a month during the hottest part of the summer)...some, probably.  I've netted some BND, and shiner sp. in very slow moving, almost stagnant pools and oxbows in creeks in Northern VA that were well into the 80's and appeared fine.  Speaking in terms of specimens in captivity, I've experienced the same tolerance for VA species collected in the Central and SW portion of the state that did fine in [ambient] 80+ water during the summer when I had no control over the temps in a holding area.  However, those same holding areas cooled significantly during the fall, winter and spring.  I always added a ton of extra aeration.  So take from that what you will.

[centrarchid]

Warmwater fish I have worked can certainly tolerate and often still grow when temperatures get into low 80's F.  At least some can survive into low 90's for short periods although signs of stress very evident and likely growth not possible with most.  Mosquito fish are among those that can operate at the higher extremes routinely.  Bluegill and Warmouth, as juveniles, can be found in shallows where temperatures get into the high 80's F where they appear to be feeding.  I think those same fish will, if they can retreat to cooler water at least periodically.  The warmer areas may be a refuge from predators. 

[Moontanman]

Hello all! Here's a question...can most fish from the southern part of the country (Florida, Georgia, etc) handle temps in the 80's reasonably well? I tried looking this up but couldn't find it. Thanks 

 

Can I ask why would want to keep fish above 80 degrees? 

[gerald]

I can't speak for Joshaeus, but for those of us in old houses with no basement or room that can be cooled separately from the rest of the house, it gets expensive to keep the house below 80 in July-Sep.   I no longer try to keep anything that cant handle a couple months of 80-84 F.   My upper-rack tanks usually stay a couple degrees warmer than the house temp, I guess due to lights on the tanks below.  Some species (e.g. mtn redbelly dace, most darters), may get thin during that time, but their condition recovers in the fall.

[swampfish]

People who keep tropical fish, particularly cichlids and guppies, commonly keep their fish rooms in the low 80's degrees F. Tropical fish information sources usually recommend this. Keeping natives in fish rooms or tanks with tropicals might have caused this question to be raised, as I have been asked this question for this reason frequently.

 

Temperatures in the 80's are used by tropical fish breeders as it speeds up development, allowing them to produce fish large enough to reproduce and sell quicker. Fish collecting trips to the Amazon and its tributaries by North Americans, Europeans, and other foreign fish enthusiasts are generally taken during the dry season when transportation is easier and fish are concentrated in smaller, shallower bodies of water. These water bodies are likely warmer than much of the year due to shallowness and reduced current. Water temperatures in the 80's degrees F are commonly reported pn these collection trips. Books and other information written about how to keep tropical fish are written primarily by fish breeders and collectors. 

 

I keep tropical fish in the low 70's and find that they live longer, commonly two to three times as long as reported from those with warmer tanks. However, I do not generally keep cichlids except for occasional angelfish, so their needs may be different. I find it interesting that when I started keeping tropical fish in the 1960's, the literature recommended water temperatures in the low to mid 70's, now they recommend the low 80's for the same fish species. When determining the temperatures to maintain tropical fish, I refer to the Baensch series of books as they seem to recommend a wider temperature range than other sources of information. 

 

Phil Nixon

[centrarchid]

Above ground tanks in near full sun like mine also experience high temperatures.  Mine was clearly in the upper 80's about 2 weeks ago.  In extended literal zone of lakes with clear water lacking circulation you can also get the really warm waters.  The elevated temperatures are not as unusual as the literature leaves out.  Nobody cares about the very shallow littoral zones of lentic systems.

[centrarchid]

Better start because this will be reality for many aquatic systems in the next hundred or so years.  In 500 years things may get really tough but we do not think that far ahead.  I am getting bitter.

[Moontanman]

People who keep tropical fish, particularly cichlids and guppies, commonly keep their fish rooms in the low 80's degrees F. Tropical fish information sources usually recommend this. Keeping natives in fish rooms or tanks with tropicals might have caused this question to be raised, as I have been asked this question for this reason frequently.

 

Temperatures in the 80's are used by tropical fish breeders as it speeds up development, allowing them to produce fish large enough to reproduce and sell quicker. Fish collecting trips to the Amazon and its tributaries by North Americans, Europeans, and other foreign fish enthusiasts are generally taken during the dry season when transportation is easier and fish are concentrated in smaller, shallower bodies of water. These water bodies are likely warmer than much of the year due to shallowness and reduced current. Water temperatures in the 80's degrees F are commonly reported pn these collection trips. Books and other information written about how to keep tropical fish are written primarily by fish breeders and collectors. 

 

I keep tropical fish in the low 70's and find that they live longer, commonly two to three times as long as reported from those with warmer tanks. However, I do not generally keep cichlids except for occasional angelfish, so their needs may be different. I find it interesting that when I started keeping tropical fish in the 1960's, the literature recommended water temperatures in the low to mid 70's, now they recommend the low 80's for the same fish species. When determining the temperatures to maintain tropical fish, I refer to the Baensch series of books as they seem to recommend a wider temperature range than other sources of information. 

 

Phil Nixon

 

I honestly think the idea of keeping tropicals at such high temps is intended to sell more heaters and to sell more fish as fish live fast and die young at high temps. I keep my fish at room temperature. My wife insists on the indoor temps being low enough to hang meat... well maybe not quite that low, but mid 70's in the summer and mid 60s to low 70s in the winter. The temp in my 75 right now is 72. I understand that discus need really warm water but I have never kept them so I don't know if they do or not. I do know that high temps are not necessary for most fish, tropical or temperate and more importantly to us native fish keepers low temps are not necessary for most temperate fish either. 

 

One fish that seems to get a lot of high temperature attention is cardinal tetras, I've kept them for many years and in room temp water that in the winter often hovered around 68 degrees and I'l have cardinals that lived more than 5 years and held beautiful coloration and health the entire time. 

[Khai Wan]

I have kept rainbow shiners outside during summer, over 90's. They live through the summer in a flower tub with rain water. I don't recall feeding them, they just eat mosquitos. Rainbow shiners are pretty hardy. Nowadays due to work load, I seldom change their water. Probably once a month I do 100%, and they are strong. I experimented not turning hood light for months, just only using room ambient light. And guess what? They still breed twice a month.

[Michael Wolfe]

I have to disagree with some of you (whom I greatly respect). Outside the bs are not in the 90s just because the air is that hot. Even if the top surface water is that hot. With any cover at all the bottom of a 100 gallon container can be 20 degrees lower. And literal zones are an in and out thing, not a constant habitat. If the water in your above ground tanks were in the 80s or 90s for weeks at a time the fish would die. I proved this by adding circulation to my outdoor tanks and killing all the fish by homogenizing the temp. The natural layering of temperatures it what is saving your fish.

[centrarchid]

Experiment time!

 

Measure water temperature of you culture units as a function of time of day..  Shading, evaporative cooling, above versus below ground, and when above ground plants versus something solid like pavement of concrete below.  A couple other factors can be considered; humidity and diel temperature variations.  And turbidity as that make a huge different in stock ponds.

[centrarchid]

Remember the temperature can also be pushing 110 F. with night time temperature in the middle to high 80's.

[Moontanman]

I have to disagree with some of you (whom I greatly respect). Outside the bs are not in the 90s just because the air is that hot. Even if the top surface water is that hot. With any cover at all the bottom of a 100 gallon container can be 20 degrees lower. And literal zones are an in and out thing, not a constant habitat. If the water in your above ground tanks were in the 80s or 90s for weeks at a time the fish would die. I proved this by adding circulation to my outdoor tanks and killing all the fish by homogenizing the temp. The natural layering of temperatures it what is saving your fish.

 

Here in SENC, a 50 gallon tank sitting in a shaded locale in the summer can average well above 85 degrees and sometimes above 90. The humidity is so high here this time of year evaporative cooling is minimal at best. Even night time temps are often above 90. Ground water is in the mid 70s and above the thermocline in lakes can be warm enough to make swimming tiresome from overheating. Blackwater absorbs a lot of heat and high humidity keeps it from cooling as fast as it would normally. I know I've seined fish out of small bodies of water that felt like a warm bathtub and the water was only a few inches deep and the sand on the bottom was hot as well. i once caught several small squid from such a warm tide pool, I was really surprised that squid could live even for a short time in water that was almost hot to the touch. 

 

I used to snorkel in a local lake called silver lake, I would float around in the shallows and big bass would stay under me in the shade of my body. sunfish would do the same but more active minnows did not. The water was very warm, well above 80, maybe well above 90, below the thermocline the water would be in the mid 70s. Ground water flowing up through the bottom was mid 70s. 

 

Of course fish do have the option of moving around in lakes with thermoclines and I am sure they do so when the water really gets hot in the summer but the smaller fish would seem to spend more time in warm shallow water than the bigger fish... 

 

I do not like to keep my fish above 80, i prefer low 70s to high 60s even for tropicals. I think the high temps shortens the life of the fish but I am often surprised at how warm the water can be in local ponds, creeks and swamps in the summer... 

[gerald]

Even a 20 gallon plastic tub above ground will stratify.  Drop a thermometer to the bottom on a hot day and you may be amazed how much cooler it can be, even after several consecutive hot days.  I've seen Michael's kill-the-fish-by-overheating-them-with aeration thing happen too.

[centrarchid]

Yesterday evening my stock tank temperature peaked @ 82 F. This well after peak of ambient temperatures that did not quite reach 100 F during day. Night time temperatures critical as is solar gain which peaked back in June. This will be repeated next year. Will also try to monitor an expansive littoral zone of a pond where water current minimal and solar gain is very high.

[centrarchid]

The paper below directly related to this discussion.  I will not say it in public but some of my work is anticipating the rise in temperature.

 

http://www.nature.co...otcallback=true

 

 

How did the fishes persist through the Paleocene-Eocene Thermal Maximum?  

[tricolor]

I have had rainbow shiner and some cyprinellas spawned in 30'C.