SDWalters, on 07 November 2009 - 09:30 AM, said:
I have had a shoal of 4 Tiger barbs for around 8 months now, When i first got them they had distinctive markings i.e. black stripes on an orange body... Over time they stripes have become less distinctive and it seems the black has spread to more scales and now there looks to be a greenish tint (almost like they are growing algae!!) on the new black scales.
Another thing, i just added another tiger to the group to make 5, but this one seems different, the 4 original tigers have quite bright orange nose/mouths but the new one has a duller orange (like the rest of the body) nose/mouth, is this down to maturity or gender??
Any information would be great

Question #1: Color variations abound. There is a green morph and perhaps your fish come from stock that has intermingled with this morph. There is a gold/albino morph too. Me, I prefer the originals, but the originals were used to create the other two color varieties, so it is entirely possible that yours may just have more of what it takes to create that green morph.
Question #2: How long was it since you got this new one? He/she may need more time to settle in. Nice that your old ones have color. TB gender can be also distinguished by color. If memory serves, males have more red and dorsal fin is edged with bright red in males. Anal and ventral fins are also red. I can't remember off-hand if the pectorals are red as well. Females are much, much fatter and have less red.
I love TBs, they are a great fish. If you can, I would up the numbers to at least 8. It will spread agression.