A reader asks expert Neale Monks why some of the new baby guppies in her tank are albino...
Q) I have been keeping tropical fish for over 45 years. At the moment I have two large tanks running, one of which contains guppies.
About six months ago, as I was getting a lot of red colours in the babies, I added four new brightly coloured males. I am now getting a lot of albino babies. Is this unusual? I’ve not seen any albino Guppies in the shops.
DIANE COOPER, VIA EMAIL
A) Neale says: I wonder if these are true albinos or what are sometimes bred and marketed as ‘blonde’ guppies? These are unmarked guppies that are basically pale yellow with black pupils —on true albinos, the body is basically pinkish-white and the pupils are red, something that you can clearly see.
Some blonde guppy varieties have red fins as well, and these are called ‘red blonde’ guppies. Doubtless, other varieties exist as well. The main thing here is that since the pupils are black, the fish aren’t true albinos, so are producing at least some colour pigments. In fact, I believe that blonde guppies are leucistic fish, leucism describing the situation where only some tissues fail to produce certain colour pigments, whereas albinos are animals that don’t produce any colour pigments at all.
Albino guppies do exist, but they’re much less common, and when they are sold it is usually at a premium price. The curious thing here is how guppy breeders classify these fish. In short, any fish with red eyes is called an albino, whether or not it matches the traditional expectation we have of an all-white fish with pink or red eyes.
As such, there are various strains out there, such as albino red snakeskin guppies that have the traditional snakeskin body markings and solid red fins, so don’t resemble the classic albino animal at all, except that they do have red eyes.
Albinism in guppies — basically, the presence of a red or pink pupil — is a recessive trait. You can have two store-bought guppies carrying that trait but not expressing it. Put them together, let them breed, and some fraction of their offspring — theoretically, around a quarter — will now express that trait.
Without seeing your fry, I cannot be sure whether we’re talking about essentially white fish with red pupils, or whether you’re using the guppy breeder definition and referring to offspring with colours on their bodies and fins, but with red rather than black pupils.
But I hope the above does at least explain some of the possibilities. Yes, albinism can seem to come out of nowhere because it’s a recessive trait, and because quite a few varieties are genetically albinos by the standards of guppy breeders, even ones with coloured fins and bodies, that albinism gene can be carried by all sorts of fish we wouldn’t immediately recognise as albinos when compared with the all-white albino animals we see from time to time.