Tropical Fish Forum

Tropical Fish Keeping Help and Advice => Fish Identification => Topic started by: barneyadi on February 23, 2020, 01:59:23 PM

Title: When to know if a guppy is male or female.
Post by: barneyadi on February 23, 2020, 01:59:23 PM

Hi All

When I brought my Harlequins there was a very small fish in with them. Guy said it was probably a guppy but due to its siz\e might not make it. Now 3 weeks on the guppy is growing. I am thinking of transferring it to my guppy tank but need to make sure it is not a female. How old should they be to hopefully work out what sex they are?

Title: Re: When to know if a guppy is male or female.
Post by: Matt on February 23, 2020, 03:39:25 PM

I’m sure others will be along very soon with much more experience but from what I do know the females often have super coloured bodies and are much more drab in colouration overall. I think their larger too but this is probably not helpful if juvenile.  Wait for other before you make a firm judgement! I’m no expert as I’ve never kept them personally!!

Title: Re: When to know if a guppy is male or female.
Post by: fcmf on February 23, 2020, 04:45:32 PM

Likewise - I have no personal experience, so please await more experienced owners' views on this. However, in the interim, you may find this helpful https://www.wikihow.com/Identify-Male-and-Female-Guppies - I can't comment on its quality, though! Looking elsewhere, some trusted sources say that it's difficult to tell sex until guppies are 2+ months' old and the gonopodium/ anal fin is the key feature to look out for.

Title: Re: When to know if a guppy is male or female.
Post by: Sue on February 23, 2020, 04:46:57 PM

I used to have endlers, back in the days before I realised my water is too soft for them  :-[

All livebearers look female until puberty. Then with males the first ray of the anal fin begins to elongate and the rest of the fin shrinks. A magnifying glass is useful for spotting this early. It does take at least a couple of months though. I would wait a while longer yet.
Males tend to be more colourful but you can't rely on that as there are colourful females these days. And females tend to have small round tails - but so do males until puberty.

Title: Re: When to know if a guppy is male or female.
Post by: Littlefish on February 23, 2020, 04:53:30 PM

I've not kept guppies but I have kept v. platies (another live bearer) and the anal fin was longer/pointed on the male platy.
Knowing that guppies, like platies, tend to breed at any/every available opportunity, I'd suggest keeping the new one away from the others until you can be sure.

Title: Re: When to know if a guppy is male or female.
Post by: Hampalong on February 28, 2020, 05:03:44 AM

Guppies can be easily sexed from about 4 weeks old. A male will develop its gonopodium at this age, and start to develop its colours, and a female will develop a gravid spot just behind the anal fin.
They become sexually mature at about 6 weeks.