Unusual Head & Tail Light Tetra

[fm1978]

Hi guys
 
Would anyone be able to shed some light (pun intended) on one of my new Tetras?
 
He/She has quite different colouring than the others... Here it is on the right...
 

 
And here the middle fishy...
 

 
He/She seems much more brilliantly silver and seems to have no Head or Tail Light. Any one know why???
 

 

[DreamertK]

1. Genetic variant.
2. Species of fish labeled wrongly.
3. Stress
 
The only thing it has in common with the rest is that black marking on the tail...

 

[fm1978]

Yes, it does have the black mark and in a lot of ways it's very similar to the rest, but, it's also got some quite glaring differences. At first I thought it might be a slightly more mature female - the animal kingdom has lots of examples of the females being less colourful.
 
I had kind of ruled stress out as she (I'm calling her she until I'm told otherwise) appeared relaxed and schooling with the rest as well as going for food straight away.
 
I'm going for the variant for the moment but it is quite strange how she's quite so different. Another thing I noticed was that she's ever so slightly more elongated than the rest...

 

[the_lock_man]

Instinct says it isn't a h&tl. Females should be heavier, not lighter, and this fish doesn't have the "lights"

 

[N0body Of The Goat]

A rogue Gold Tetra (Hemigrammus rodwayi)?

 

[the_lock_man]

A rogue Gold Tetra (Hemigrammus rodwayi)?

 
Could well be
 

Image from Seriously Fish

 

[fluttermoth]

I had one of those (gold tetra) turn up in a group of silvertips I bought a few years ago; maybe hey're a common 'contaminant'?!

 

[fm1978]

Ahhh, a gold tetra...good spotting. I shall have closer look at her and compare to some images of golds.

How would her behaviour differ if at all?