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PostPosted: Wed Jun 27, 2012 8:37 pm 

Joined: Fri Dec 24, 2004 10:39 pm
Posts: 2955
Location: Toronto Canada
Professor Eugene Balon very recently passed away. He did quite a bit of work on the subject of environmental influence on developmental processes.

Here is a bit of work he did researching the domestication history of Japanese Koi, Carp, Goldfish.
Balon talks about phenotypes, always through the lens of binary choice decisions being made by embryo, through to the larva and well beyond.

Once you think about it, it's obvious that huge differences can easily appear. Whole new organs appear or maybe disappear in the early life, and a pause in forming organs is an obvious big difference that does happen. Balon saw development as always being the results of binary choice decisions, and in fish and birds he noted the general forms "precocial", which is a headlong rush to the common specialized niche fitting form directly. while altricial is the more general , slower form, more like the ancestral form. At any time, though, the choice may be to head in one direction or the other - that is, that a generally altricial form may take a precocial turn. ... 0155569282

Balon astutely observes that age of a fish like an angelfish can vary...depending on whether you take it from hatching or from egg deposition and fertilization.

Due to the effect of temperature alone, on the egg hatch time, your babies may actually be older or younger than their development shows.

Slow eggs tend to get fungus, be eaten, be discarded or neglected by the keeper ( second major environmental action we've applied to the spawn; temperature control and then immediate selection against slow development) .

I like Eugene's thinking on these subjects.

PostPosted: Sat Jun 30, 2012 3:32 am 
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Joined: Mon Aug 01, 2011 5:36 pm
Posts: 43
Location: Kunkletown, PA.
Very interesting topic...


TAS President 2013 & Supporter of Ken kennedy, Mike Gibbs & Dave Ramirez's Work...



PostPosted: Sat Jun 30, 2012 10:58 am 
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Joined: Thu May 18, 2006 10:12 am
Posts: 502
Location: Somerset West, South Africa
Hi Everyone,

From my past threads that I have posted about a year ago after visiting Simon Forkel in Germany, I would like to make some comments here. Simon keeps all his altums in tanks with substrate which is fairly fine gravel. He does this because as a registered breeder in Germany, the authorities will not permit him to breed fish in bare bottom tanks, but also because he has observed very distinct advantages from using gravel. I see similar differences here to what he has observed and that is that fishes that are raised in tanks without gravel are forever dragging their ventral fins on the bare bottom tank as a result of which muck and bacteria stick to these fins and damage them to the point where they cannot recover. In baby scalare angels, I am sure many of you have observed that they can all of a sudden become aggressive towards each other and start biting off each others fins and then they do not regrow when the fish become adults. In the same way, if altums loose their ventral fins when they are small because they drag them on bare bottom glass, they never recover and grow them out properly. I do not have any altums at the moment, but when I next obtain some more, then I will only keep them in a tank with gravel, never again bare bottom, it permanently damages their fins.

Kind regards,


Somerset West, South Africa

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