temperature question

[cageman]

hello,

recently I have attended a presentation of someone who has been to French-Guyana. he found apisto's and many other fish. in some habitats he measured a temperature of 32°C/89°F, and this was no exeption.
are these temperatures frequent in nature and when and for how long can they last. I'm really interested in how the fish cope with these conditions.

regards,

cageman

 

[cdawson]

Only during the dry season where the water would be lower, so it wouldn't be long term.

 

[cageman]

and what is 'wouldn't be long term'?
and how do the fish cope with this?

 

[cdawson]

and what is 'wouldn't be long term'?
and how do the fish cope with this?

Basically the dry season lasts from may until october, temperatures are not that high all the time but alot of the time they are.
Tropical fish are able to withstand pretty harsh heat, and 89 really isn't that high when you compare it to the extremes. I've never heard of someone killing their fish at a temp of 89f. Some people keep discus at temps of 88.

 

[cageman]

so let's say 35°C/95°F wouldn't be a problem for any length of time?
I'm asking this because it's summer again here, not that the temperatures reach these hights in my tank but was curious.
most of the time they are around 82,5°F

 

[Mike Wise]

You must realize that in Nature fish have the ability to move into deeper water (or water shaded by trees) that is usually cooler. Römer observed that dominant apistos always chose to live in waters around 26ºC/79ºF and forced to less dominant fish into cooler (deeper) or warmer (shallower) waters.

 

[cageman]

interesting again, thanks mike!
so the colder water usually houses more subdominant fish.
are there more things to know about watertemperatures?
and how much effect has for instance the PH on the male/female ratio when young ones are born? I know that warmer water produces more males. but how much effect has the PH on that?

 

[Mike Wise]

pH has less importance with sex ratios, but more with the number of fertile eggs. Again, the temperature at the time of spawning is not as important as the temperature at which the fry are raised for the first 6 - 10 weeks. This temperature determines sex ratios.

 

[cageman]

thanks again. that about covers is I think.