Re: [RML] Pseudomugil cynadorsalis Melanotaenia pygmae

Dave & Robyn Wilson (rwilson at octa4.net.au)
Fri, 1 Jun 2001 00:18:51 +0930

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Re: [RML] Pseudomugil cynadorsalis Melanotaenia pygmae
Danny,
 I will try answer some of that.   I have collected Pseudomugil cynadorsalis in Broome as well as here in Darwin.  I have never found them above tidal influence or outside estuarine creeks in the open ocean.   They are very common in all the small tidal creeks around Dawin.  These small creeks run fresh for three or more months per year during and after the wet season then gradually return to salt water after the rains stop.

Can anyone tell me if P.cyanodorsalis   is found in any permanent freshwater, (land locked) or are they just seasonal bouts of freshwater, and are they also found in open sea areas or sheltered harbours and eustary.
Also is their colour enhanced by being in salty water?
 What can I expect the life span in captivity is?

Their life expectancy at my place is very short because I feed them to baby mangrove jacks and small gudgeons.  I have never kept them long term
As I guess they would be pretty well annual in the wild.

In the creeks near here there are always millions of smaller specimens with very few larger models among them, so assuming them annual is probably reasonable.   They are not in a very safe position in the food chain.  There is a magnificent little algae eating shrimp from the Atyid family among them, the shrimps convert to fresh and will clean up an algae problem in a planted aquarium very quickly.

In our shop I have some in a very small display tank with 50/50 brackish and they colour pretty good in the natural sun light.

I don't think there is a need to be rigid with your salinities because they get fluctuations where they live.

Cheers
Dave