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Re: Iron and Eggs

>	3 days ago, I added an iron supplement for my plants. The taenia have
> gone from being a curious but drab fish to absolute striking coloration.
> 3 females spawned within hours of each other yesterday, as did the
> cacatuoides. All of these fish, bar one pair of taenia, hadn't spawned
> in months.


Yesterday I was reading Horne & Goldman's "Limnology" - courtesy of a 
suggestion by Roxanne Bittman. In the section on the Amazon (contained in 
"Big Rivers and their Flood Plains" are the following selected statements:

"The light-linmited, nutrient-rich white-water river and its 
nutrient-depleted, acidic clearwater tributaries are unproductive, 
whereas the flooded varsia <the flood plain> is extremely productive. ...
In the early flood stages, the overflowing waters become enriched with 
nitrate and phosphate leached from the forest floor. ...
Many Amazon fish benefit from the annual flood. They migrate from the 
main river to feed in the newly flooded varsia and then migrate again to 
breed elsewhere in the main stem of the river. Other fish breed in the 
varsia itself, and the young of these fish not only find ample food but 
may avoid density-dependent depredation."

My guess is that the dwarf cichlids are originally from 
"nutrient-depleted, acidic clearwater tributaries" and the fertilisation 
triggered a "flood time" response. At least, that's a very neat 
explanation and another reason I should continue reading this book a 
little more closely.

David Aiken