Dorsal fin extension. when does it grow?

[suisoman2]

Hi all,
I have seen that adult discus, especially males develop an extension to their dorsal fin.
I have seen it on pictures and large breeding males at breeders tanks. It makes the fish look really gracefull to me!
Now my question: when does this extension develop and do only males have his extension?
Does it develop when the fish reaches maturity , before that at X months, or do they really need to be 2 years old or so.
Any experiences with this fin development? Is there any relation with the length of the pelvic fins ?
( pelvic are the long thing ones that seem to have no function?) :-\

Suisoman Dirk

[April]

well..i think the pelvic fins have a function..they can move them. ive seen them twitch them .
as far as the extension goes..not all get it. some males do and some dont. it does grow once they mature..all different. im sure it has to do with the bloodlines and genetics. luck of the draw.
sometimes you can see a tiny little point starting. and it will grow from there as it matures and ages.
does seem to be mostly males..but some females do as well. luck of the draw on your part.

[suisoman2]

Update:

My juveniles are now nearing their first birthday, went on a business trip last week and guess what I found when coming home: a couple formed and eggs are against the glass. :) All of them eggs dissapeared within 48 hours though. ( no special efforts taken anyway). But I also noticed that 2 of the fish have started to grow these extensions :). So FYI , they are now 12 months , have just started pairing up, have intensified colours and social interaction, and they just started development of the extension. Coincidence? ???
Anyway I am a happy man as my babies reach maturity , and these extensions really make them look good I think. :bounce2:

PS: They are flachenturkis and redtutkis , german ancesters.

Dosal fin extension can appear on both male and female if their diet is mainly high protein diet such as beefheart. Body shape of young fish can be altered by high Calcium and amino acid diet.
Jimmy.

[Anonapersona]

Dosal fin extension can appear on both male and female if their diet is mainly high protein diet such as beefheart. Body shape of young fish can be altered by high Calcium and amino acid diet.
Jimmy.


A tantalizing tidbit of information!

Can you elaborate? Altered by calcium... how? My water has high calcium and low magnesium, do I need to add a bit of magnesium? Amino acids...what sorces and to what effect?