You can't say "temperatures for corys", as there are corys that like almost all temperatures from 15'C to 30'C - which is pretty much the same range as the tropical and subtropical fish in general likes.
For Loricariidae, you can use the search feature in the Cat-eLog:
http://www.planetcatfish.com/catelog/search.php
There are two options:
Search by occurrence - if the fish are from the same river, they should like the same conditions [obviously, large rivers may have very different conditions at either end, so some discression may be necessary].
Search by temperature - select min/max temperature close to the temp you want for the Corys, e.g. if you keep your corys at 22'C, set min/max to 22 and 23 or something like that.
In both cases, you may want to for example select "Loricariidae" as a family first, so that you restrict the search to cat-elog entries for that family.
You can even restrict to Genus.
Unfortunately, that's not quite so easy for other fishes, as the Cat-eLog doesn't cover those.
Fishbase has a "geographical" search, so you can use that to search for fishes from the same river, if you like.
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Mats
