In my area large volume outside ponds get down to about 7 degrees.
At this temperature, P. signifer survives as will some strains of Mel.
duboulayi (and Mel. fluviatilis). I haven't found any other Melanotaenia
that make it past 13 degrees (Have tried M.s. tatei (Georgina River), M.s.
splendida (one of the Atherton region ones) and M.s. inornata (two types).
The tatei did the best out of these, behaving "normally" right up to the
point when they disappeared/died. Rhadinocentrus ornatus from around Coffs
Harbour can certainly go as low as 10-12 degrees but I haven't tried them
over winter in a pond yet.
I have some P. mellis in an unheated 60l tank behind my desk at work. The RC
air conditioning goes off over the weekend and it probably gets pretty cold
in there but they always seem fit and healthy.
In the Gudgeon department, most purple spots don't seem to appreciate low
temperatures, possibly requiring at least 15 degrees but Empires from around
Sydney are still feeding at 10 degrees (look pretty dull though). Many of
the other temperate Hypseleotris are active at even lower temperatures. I
just remembered your question was about rainbows and blue-eyes so I'll shut
> -----Original Message-----
> From: Graeme Finsen/Be Sharp-Rentacomputer [SMTP:finsen at powerup.com.au]
> Sent: Wednesday, July 11, 2001 8:23 PM
> To: rainbowfish at pcug.org.au
> Subject: [RML] Cold tolerance
> Wow!!! Isn't the RML quiet.
> Lets warm things up with some questions:
> What is everybody out there in RMLand experiences with the cold tolerance
> Blue-eyes and rainbows? I am curious with the cold snap that Brisbane has
> experienced, to see what the locals are/have done and also from outside
> I have some Cape P.gertrudae and mainly Nth Qld rainbows.
> Hopefully will catch up with the ANGFA Q committee Friday.
> Graeme $2 Finsen