PlanetCatfish.com

The Cat-eLog page lists this fish's temperature at 68-73.4°F, while the 's temperature is listed at 69.8-86°F. These fish have nearly identical distributions. Is it possible that the formosae's temperature data is incorrect, and that the formosae may be able to live in warmer temperatures?

Good question, neither seem that accurate. Both will do OK in upto 78F, but 86F seems too high for either being kept sensibly. I'll change them.

Jools

Jools wrote: ↑31 May 2017, 06:58 Good question, neither seem that accurate. Both will do OK in upto 78F, but 86F seems too high for either being kept sensibly.

I'm not disagreeing with you, but for what it's worth, the 86F is taken from the original species description of joropo. I can't attest to the conditions or universality of that temperature as a common experience for the fish, but apparently some fish were found at it.

Cheers, Eric

The thing is, in the subtropics - especially where there are no trees, during daylight temps can go up rapidly, and during the night, the will drop again.

Once, on a hot day I came home and decided to measure the temerature of the tanks I had outdoors, in full sun. It was 33 to 37 C, for fish from Uruguay. Far too highl, obviously, and so I changed water. I had 0 casualties

The fish were collected by myself, most often in kneedeep water. Assuming no reflection, kneedeep water (60 cm, 2 feet) can raise 1.5 C (close to 2 F) an hour in full sun (actually, this is 1000 watts a square meter. I live @ 53 degrees morth, and our max is just over 1100. In south Spain or Uruguay this can be much more). As many waters in Uruguay are grown over with plants, the reflection is low - that is, a significant part of het sun energy will be taken in. Fish from this region must be hardy where it comes to temperatures.

BUT the hot water will only be hot for a few hours. That is, if a fish is collected at 15:00 in water of 32 C in Uruguay - that does not tell me the fish can be kept at this 32 C.

Because, keeping a fish at a certain temperature will imply that is the temperature for a long while - at least a week

Bas Pels wrote: ↑31 May 2017, 07:46The thing is, in the subtropics - especially where there are no trees, during daylight temps can go up rapidly, and during the night, the will drop again...

BUT the hot water will only be hot for a few hours. That is, if a fish is collected at 15:00 in water of 32 C in Uruguay - that does not tell me the fish can be kept at this 32 C.

Because, keeping a fish at a certain temperature will imply that is the temperature for a long while - at least a week

Exactly. That is the point I was making about the reliability of the measurements cited in the paper.

Cheers, Eric

Yup, so while the parameters are introduced "in the wild" which is good, if we put them in the species data, some yahoo will start arguing that it's a great idea to keep these fishes with discus because "PlanetCatfish says so". So, we go for good parameters for care and also show the scientific research. All good!

Jools