Are we keeping our cichlids too warm!

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First paper that comes up for me using google, numerous citations involving fish that support what Stanz, myself, and many other people have stated over the years.

Being cool: how body temperature influences ageing and longevity

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4486781/

Obviously one is not going to find data on every species of ornamental fish kept in captivity, but for myself it's not a huge leap to extrapolate much of the data available, across the board to numerous species of finfish.
 
Are you able to provide any studies done on fish where their lifespan was dramatically decreased due to higher temps?

I'm just a guy who's been into fish a long time. I'm not a scientist with a journal.
I share what I've learned,take it or leave it. I don't mind either way.

I also wonder how being born and raised in tanks have changed the needs of the fish. If you are going after wild caught species then I understand the desire to replicate that environment. But most of out fish we keep have been raised in tanks that likely had similar temps to that of which we all keep.

I don't believe a few generations in wholesalers tanks, wipes thousands of years of evolution from a fish.
I also believe many species sold in shops are infact wild caught.
I was at a wholesaler recently. He had a huge south American selection, mostly catfish. All wild caught.
There are probably more wild caught fish in some stores than some may realise.

We often ignore recommended pH values for tank raised fish stating a stable ph is what is important. Maybe temps are similar in that way.

I don't believe so. At least not for all fish.
Ph and hardness values have stopped me from keeping quite a few fish i would like to have kept.i know my water will do them no good.

I see Rd has answered your other questions.
Sorry I can't provide any studies :)
 
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BTW... Many tank raised species of cichlids have proven to do poorly when kept in pH values outside of their normal range. Many believe this is do to the bacteria that is sometimes present in higher pH water, and not present in low pH values. HITH is a common symptom in many SA cichlids when they are kept in higher pH water.

I read a recent article by Ted Judy that supports this observation, in particular it had to do Altum Angels. He found that they are in water with a PH of 3-4, basically devoid of many bacteria and high temperatures of 84F+. His assertion to "unexplained" and rapid deaths of altums were due to bacteria existing in higher PH water. The exporters quickly recognized this quickly, and add acid to the water holding tanks to make sure that the PH is in that range.
 
This thread filled up fast since the last time I looked. :)

I agree with the basics: Many keep fish warmer than necessary. There's enough-- centuries old observational wisdom, science studies, modern aquaculture experience-- to suggest that somewhat cooler temperatures (within an acceptable range) benefit lifespan for some fish. And the general notion has diffused to some fishkeepers from these sources in varying degrees. That might seem like less than a resoundingly assertive stance-- and with good reason, it's complicated, and the whys, hows, and other particulars are still being studied.

But there are science studies such as:
https://www.sciencedirect.com/science/article/pii/S0531556516300559
Temperature is a key environmental factor that greatly affects lifespan in all animals studied. There are many cases where modestly lower environmental temperatures greatly increase the lifespan of ectotherms. For example, a 5 °C decrease in water temperature extends lifespan of a small, South American fish (genus Cyanolebias) by nearly 100% (Rikke and Johnson, 2004). In another fish model, lowering environmental temperature from 25 °C to 22 °C caused not only a significant increase in mean and maximum lifespan, but also delayed the onset of aging markers such as diminished cognitive ability and lipofuscin accumulation (Valenzano et al., 2006).

And competent fishkeeping expertise such as: http://www.angelsplus.com/ArticleAquariumTemp.htm
 
Not to derail the temp conversation, but this is a past thread (one of many) discussing the problem with keeping certain species of fish outside their natural water parameters.

https://www.monsterfishkeepers.com/forums/threads/uaru-panda.657613/

Discus come to mind. They have notoriously low ph requirements but if you go into certain pet shops that keep them in tap water. You ask why and the response is that captive bred specimens are raised in 7.0 so they have hardier fish. I never bought that premise.
 
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Designer strains of discus, which is typically what one sees in pets shops, are for the most part a non issue when it comes to higher pH values. Lower pH values ensure higher hatch rates when breeding, but higher pH and TDS values (mineral content) can actually help growth, and overall health of juveniles. A local breeder bred & raised discus in this manner for several decades, with local water parameters of pH 8.0-8.2. His discus were healthy as horses.

I was thinking more along the lines of the species mentioned in the link I posted, Panda uaru and Pterophyllum altum, and/or some of the more sensitive Geophagus species that are notorious for getting HITH, even when kept in pristine water quality and fed a first rate diet. This is often the case even with domestic strains of these species. They just don't seem to be able to cope very well with the bacteria found in higher pH values. Sometimes health issues show up early on, with others it can take years to develop. I suspect that incorrect water temperatures could lead to the same chronic issues. Any form of stress is No Bueno.
 
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You can keep discus in tap water. But ask yourself why discus keepers do tons of water changes. IMO it's because the fish, like altums and U. fernandezyepezi, evolved in very clean water, and so any elevated levels of DOC or bacteria will ruin a discus in short order. As soon as people post for help with a discus issue, my first question is, what are your water changes like? A large percentage of the time, they are not keeping the water clean enough, and so the discus become stressed and then susceptible to things like hexamita, HITH, bacterial infection, etc.

That same thing applies to lots of SA fish. I'm convinced that altums and panda uaru, for instance, crash on import due to bacterial issues. You're taking fish from nearly pure water that's too acidic for most bacteria to live in, and trying to acclimate them in tap water where bacteria thrive. Their immune systems are not accustomed to this.

When I imported Heros severus a couple years ago, I had the same issue. They are a blackwater species from Rio Negro, and within days were sloughing off slime coat and had full blown bacterial infections. I spent two weeks cleaning them up. Look at all the small F1 that came in sickly from Wet Spot a couple years ago. Most people lost theirs to ich or the fish just weren't "right" from the time they got them -- dark, thin, not eating well, not growing. I think that can also be linked back to the fact their parents were wild blackwater fish. One generation of being tank-raised is not enough to negate thousands of years of evolution.

Anyway, I do believe temperature plays a role in all of this. And sometimes I think people don't keep their fish warm enough. For instance, discus and panda uaru. They can withstand dips into the 70s, but try that long-term and you won't have discus or pandas for long. When they're fished in the wild, collectors have taken temperatures up into the high 80s and low 90s. I usually maintain discus in the low 80s and pandas in the mid 80s. My panda uaru tank also has a pH reading, according to my digital probe, of 3.5. So far, so good.
 
Discus come to mind. They have notoriously low ph requirements but if you go into certain pet shops that keep them in tap water. You ask why and the response is that captive bred specimens are raised in 7.0 so they have hardier fish. I never bought that premise.
That's a bit of an inherited misconception for even wild fish. It is true of wild Heckel and green discus, but field observers like Heiko Bleher report red/blue discus in pH up to 7.8.

The thousands of years adapting to a particular habitat concept doesn't always apply as forcefully as it might seem, partly an old assumption based on old science. Many habitats change over time for a variety of reasons and the genetic software endows many animals, including a number of fish, with more adaptability than some realize. Not going to go into a long discussion of genetics and it gets complicated, exactly which fish can adapt to exactly what differences from their wild origins, but a quickie example is (by now the often cited) one of tropheus intestinal length adapting to aquarium conditions.

A quick and dirty explanation of the genetics is it doesn't follow the old genes as blueprints notion but it's more like software, with "if, then, else" and other logic and controls that can switch genes off and on in response to various conditions. Another example is how some cichlids change color or sexual characteristics like head shape in response to a change in status in a group or the way some fish change gender in response to population dynamics.
 
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But ask yourself why discus keepers do tons of water changes.

Because warm water & beef = beef soup. That local breeder that I mentioned, the last decade that he kept discus, he fed pellets, almost exclusively other then a once a week treat of frozen blood worms. He performed water changes once a week. These were domestic strains, not wild, but still. I believe that he kept his discus at 82F.
 
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