Sorry if I seemed to be implying that there is only one way to keep these
fish - this was just a distillation of a range of experiences and the wat
that ended up working the best for me. I am particularly concerned about
"Poppondettas" being given the right conditions as they are in danger of
dying out here (except in a very few hands). In general most fish do best
in aquarium conditions similar to those of their natural range and as a
principle I am keen to recommend that species selections for comunities be
based first on water parameter preferences and then on behavioural
compatibility with feeding factors running third.
It is my firmly held conclusion that most fish species that are maintained
in conditions well away from their natural ones are under some degree of
metabolic stress and this will eventually be to the detriment of their
health or behaviour. Obviously this is not a hard and fast rule for
individual specimens. There is also the factor of us unconciously selecting
and fixing a strain ( of for example I. werneri ) that copes with hard
alkaline water conditions better simply by breeding them in those
conditions generation after generation.
We see this phenomenon locally where I live - the dreaded Tilapia became
established in our local water supply and bred in huge numbers in summer
and when winter came hundreds would be unable to handle the altered temp
range and die. Over the past 10 years there are fewer dying each winter and
I can assure you that the population is not on the decline. My guess is
that the cold-tolerant survivors of the initial winters are successfully
passing on this survival enhancing allele to succeeding generations.
So do we call a strain of werneri, developed by aquaculture to handle hard
alkaline water, an acceptable "natural" form ( of the fish it once was )
and would this form be able to survive back in it's natural waters if we
needed to restock for conservation purposes? Is there really much
difference ( except in appearances) in selecting and fixing any trait
whether it is a lyretail red-finned Peacock Gudgeon which is obvious or an
"invisible" metabolic variant?
I ask these questions in the true spirit of RML stirring ;-)
Bruce Hansen
ANGFA
email: bhansen at ozemail.com.au
Don't miss the ANGFA web pages at -
http://www.ozemail.com.au/~fisher/angfa.htm
----------
From: drews at webgate.net
To: rainbowfish at pcug.org.au
Subject: Re: [RML] Suitable hardness
Date: Monday, 2 December 1996 10:44
<<Now, the reason I share this with you is to demonstrate that what works
or
doesn't work for you is not the end of the story. I felt some of the replys
to
Greg Tong's inquiry SEEMED to be very final.>>