Hello, Dorothee,
sorry for the late answer (summer is no forum season for me – the garden claims its rights).
That’s a good question. How are my simoni shrimp now?
They are not “exploding” in reproduction – that’s the same as you observe. But they are doing well, as far as I can see. There are times when I think their number declines. But then again I see many young half grown ones. I don’t know if they really have ups and downs in their population, but I make fluctuating observations…..
Only yesterday I observed some younger ones which measured about 1 cm in my quindecim tank – and some rather big ones, if not to say giants :huh:
My conclusion: They are doing well, but don’t show enormous reproduction rates (maybe they do, but the newly hatched shrimp are eaten by the paros? A welcome side effect).
They obviously moult successfully despite of the lack of water hardness. Maybe they benefit from the fact that the live food I fetch from my garden pond contains many crustacea like daphnia – providing them with all they need to build up their own shells.
One thing is more than obvious and confirms me to go on with keeping Caridina simoni in my paro tanks: The cleaning effect! You can clearly see which tanks contain shrimp and which don’t. This effect – the eradication of organic waste and thus keeping the organic load of the water down – is something I wouldn’t like to go without anymore.