Re: [RML] P. cyanodorsalis revisited

Adrian Tappin (atappin at ecn.net.au)
Wed, 27 Jan 1999 07:04:18 +1000

At 08:10 26/01/99 +1000, Bruce wrote:

>There have now been populations discovered in 3 different states - Western
>Australia (crab creek), Northern Terrirory (Buffalo Ck etc) and Queensland
>(well up the Norman River and perhaps at Weipa). I have seen the latter 2
>and they look the same but photos of the WA fish shows stronger
>thicker-bodies with stronger caudal peduncles - aquarists in Melbourne had
>no luck in maintaining this fish at all, but in fairness probably were
>operating from a freshwater perspective.

I obtained 2 pair of the Crab Ck. variety in 1982 and was never able to
breed them. I kept them in freshwater and the males developed some growth
around the mouth region and eventually die.

I also maintain the Darwin variety for around 4 years taking them through a
number of generations in both fresh and brackish water and never really
notice any difference in spawn size or survival.

I recorded the following water conditions in my diary:

Spawning conditions:
pH 8.0, Temp. 27íC, Con. 26.5 mS.
pH 8.5, Temp. 26íC.
pH 7.7, Temp. 27íC, Con. 3.1 mS.

Raising conditions:
pH 8.5, Temp. 26íC, Con. 22.7 mS.
pH 8.4, Temp. 27íC, Con. 0.55 mS, TDS 290 ppm, Hard 140 ppm.
pH 7.1, Temp. 26íC, Con. 0.55 mS
pH 8.0, Temp. 25íC, TDS 230 ppm, Con. 560 uS, Hard 120 ppm.
pH 8.0, Temp. 21íC, TDS 230 ppm, Con. 502 uS, Hard 130 ppm.

You will notice the difference in mS (fresh and brackish water)
I cant say that I noticed any major differences between the Crab Ck or
Darwin populations, but I guess you need both varieties present to notice
any differences.

Adrian.

Adrian R. Tappin
"Home of the Rainbowfish"
http://www.ecn.net.au/~atappin/home.htm