Temperature considerations

[Beastije]

Hi guys. I have a small tank without a heater. From September to April/May it sits around 22-23°C then it is 25-26°C for a while until August, where for few weeks it is easily 28°C and I cool it down with ice.
A wide range.

I want one of the tiny live-bearers, neoheterandia elegans or heterandia Formosa. The elegans (tiger teddy) is supposed to be kept 24°C and above and can tolerate 30°C. The formosa (least killifish) can handle 18-26°C and would be comfortable in the autumn/winter/spring period.
Which is better for the fish? Thanks

 

[CassCats]

Formosa would be better fit i think, given it's got more overlap and no outer range for what temperatures you've got

 

[GaryE]

I caught formosa in Florida on an uncharacteristically cold day, when the water was 10 degrees celsius. The shallow habitat they were in would have to get very hot in summer. They can adapt to changes.
Neoheterandria will be a prettier fish, but its origins are far closer to the equator and therefore less wide ranging temp wise.

Drop by, I always seem to have a tank bursting with formosa! That is a fish that breeds itself.

 

[Beastije]

I would love to drop by ) US visits are not planned for this year. Will just do a US fish instead

 

[GaryE]

All my US origin fish are now made in Canada. I won't be doing any US trips either.

I will be visiting France, the Czech Republic, and maybe Portugal, Spain and England.