lnb Posted February 4, 2012 Report Share Posted February 4, 2012 All my guppys are giving birth and the fry all seem to be female ,this is happening with all my guppys even in different tanks i was wondering if the temp of the water would have anything to do with this as the temps have been hitting 30 during the day, Link to comment Share on other sites More sharing options...
jessismore0433 Posted February 4, 2012 Report Share Posted February 4, 2012 Are you sure the guppies are female? How can you tell? The only reason I say this is that my first lot of guppies I sexed at 4weeks thought they were all females but once 6-8 weeks hit I realised some were male and this was through checking for a spot with a magnifying glass. As for temperature yes they say that the temperature/ph and water conditions can all effect the outcome of sex. Link to comment Share on other sites More sharing options...
issh Posted February 4, 2012 Report Share Posted February 4, 2012 Yes temperature does affect the sex of the fry ingentaconnect Effect of temperature on sex ratio in guppy Poecilia reticulata (... The proportion of females increased gradually with decreasing temperature and the proportion of males increased gradually with increasing temperatures rather than having a threshold response in heat-treated fry. However, mortality of heat-treated fry was high; it is most likely that our results were biased by sex-dependent mortality, which were also revealed by corrected sex ratios of the treatment groups and progeny testing of some individuals. These results suggest that a major gene linked to X-chromosome could be responsible for resistance and sensitivity to both high and low temperature. Link to comment Share on other sites More sharing options...
lnb Posted February 4, 2012 Author Report Share Posted February 4, 2012 Are you sure the guppies are female? How can you tell? The only reason I say this is that my first lot of guppies I sexed at 4weeks thought they were all females but once 6-8 weeks hit I realised some were male and this was through checking for a spot with a magnifying glass.As for temperature yes they say that the temperature/ph and water conditions can all effect the outcome of sex. I thought you could tell by the shape of the anal fin females is more round and the males is long and thin Link to comment Share on other sites More sharing options...
Lennox Posted February 5, 2012 Report Share Posted February 5, 2012 I thought you could tell by the shape of the anal fin females is more round and the males is long and thin Yes this is true, and yes they all do look like females at birth. the males will come through once they start reaching maturity. Link to comment Share on other sites More sharing options...
lnb Posted February 5, 2012 Author Report Share Posted February 5, 2012 thanks to all Link to comment Share on other sites More sharing options...
Rion Posted March 30, 2012 Report Share Posted March 30, 2012 i can sex my fry at birth with 100% garentee that they are corect just by a few easy tips the anal fin on a male is pointy and a females is round and also females are born with a gravid spot. if you dont want the troubles of doing early another tip is if it colors up before the rest it is male (some case can be a female but very unlikely as a male matures faster then females in guppies) tempture pays a vital role in sexes if i am after females i tend to not have tempture over 25 as this has given me up to 90% female fry in the past hope i helped in some way Link to comment Share on other sites More sharing options...
Braddo Posted April 1, 2012 Report Share Posted April 1, 2012 male guppies develop the pointed fin at around 4 weeks. they are sexualy active by 6 weeks. At this stage the female develops the black spot proving she has been fertilised. Up to this point it is very hit and miss. Link to comment Share on other sites More sharing options...
