FAQs on Genetic Guppy
FAQs on Guppy Disease:
Guppy Disease 1,
Guppy Disease 2,
Guppy Disease 3,
Guppy Disease 4,
Guppy Disease 6,
Guppy Disease 7, Guppy Disease ,
FAQs on Guppy Disease by Category:
Nutritional (e.g. HLLE),
Infectious (Virus, Bacterial, Fungal),
Parasitic (Ich, Velvet...),
Guppies, Platies, Swordtails, Mollies by Neale Monks,
Livebearing Fishes by Bob
2, Guppy Identification,
Guppy in trouble. 12/16/10
Thank you in advance for your time and help.
Ok, I have 2 tanks 1 100L and a 65L got a 350L on the way and picking
up a 38L hospital tank later on today, as I've been meaning to get
The problem I have is with a male guppy in my 65L, I have had him since
he was born in the main tank, but recently I have noticed he
doesn't swim properly, when he does swim his tail hangs lower then
his head, and he doesn't have the normal fluid movement like the
rest, it's more like a he can't move his back almost like a
<Mmm, how old is this fish?>
The other thing he does is when is when he swims he opens his mouth all
the way and keeps it open, like he is struggling, but he tends to spend
his time lying on a leaf at the top of the tank.
All the readings are normal and the tank cycled over 10 months ago.
I will admit that the tank is over stocked due to the platys breeding,
but I'm aware of the problem and am doing regular water changes and
have a bigger already cycled tank coming.
The only thing that has occurred in that tank is my female fighter had
dropsy, well I'm pretty sure it was, her scales protruded but they
have nearly almost gone done now.
We treated her with Myxazin and Octozin and that was over a week ago
<These should be okay... in terms of the Guppy exposure>
I can send you pictures if required and more information.
My partner wants me to take him to a fish shop so they can look at him
but I think it would be far to stressful in his weekend state.
Again thank you for you advice and guidance.
<Most likely this one fish is... "defective"...
genetically/developmentally. Fishes, unlike mammals "have such
difficulties" much later in age at times. If it bothers you to
wait and see if this male will rally, you might euthanize this one
specimen. Please read here: http://wetwebmedia.com/euthanasia.htm
Sick fancy guppy 7/19/09
I have a couple of questions for you.
First is about a male fancy guppy I have. I've just noticed he has
a rather large round swelling on his upper abdomen. I'm worried
that it's likely a tumor of some sort.
<Not uncommon with inbred "fancy" fish. If the lump is
asymmetrical, i.e., bigger on one side of the body than the other, then
a tumour is a good explanation. If the fish is swollen evenly on both
sides, then constipation could be an issue, and if the swelling is such
that the scales are raised and the fish looks like a pine-cone when
viewed from above, it's dropsy (oedema).>
I hadn't noticed it a few days ago. He is in a 20 gallon tank with
6 other male guppies. I haven't had any water quality issues (that
I'm aware of) and all the other fish seem to be fine. Interestingly
enough he is an odd shape for a male guppy, kinda crooked, not slim and
streamlined like the other guppies, and he's always been this way.
I guess I'm just wondering if this sounds like it could possibly be
something treatable that I should look into more or if it really just
sounds bad and I should watch for quality of life?
<Sounds like it's simply deformed, which again, is very common
with inbred fancy Guppies.>
Once I discovered his new deformity I separated him from the other fish
(some of the other boys have a tendency to chase him around
<Good move. If things are bad for the fish and it can't enjoy
it's life, then euthanasia is an option.
Otherwise, just keep him happy but preferably away from females so any
possible bad genes aren't passed on.>
Other question, in my other tank I have 15 female fancy guppies in a 55
gallon tank. On of these fish has been getting "droopy"
slowly over the last couple of months, her tail sags far below the rest
of her body and she swims funny. Over the last couple of weeks I
noticed that she seems skinnier than normal, like she doesn't have
the round belly that they typically have, and I haven't decided if
she is actually skinny or if it's due to her malformation. She
seems to be eating ok and acting normal. Could this just be a (semi)
normal aging process for guppies, or do you think I need to be
<Depends. If you have good water quality and water chemistry, then a
single sick-looking fish is not too much of a deal. For Guppies,
you're aiming for pH 7.5 to 8, and hard water around 10-25 degrees
dH. If Guppies are the only fish in the tank, adding marine salt mix
(rather than generic aquarium salt) will stabilise the pH and hardness
while adding a little salinity, something that seems to ensure better
all-around health. You don't need much salt; 3-5 grammes per litre
I should mention that I've had both of these fish since I first got
guppies, about 1 year ago.
My last question, should be an easy one I hope. What is acceptable life
expectancy for fancy guppies? Are my 1-1.5 year old guppies becoming
<They should get to about three years in captivity, perhaps a little
Or are they just getting sick?
Fish water is yuck, but is it actually harmful?? Guppy sys.
I've been searching for this topic, but can't seem to find
anything, apart from a warning not to siphon dirty aquarium water with
your mouth. If it was answered already, and I just didn't think of
the right keywords, my apologies.
I was given (gee, thanks!) a 10 gallon aquarium with 7 guppies in it--
4 adult and 3 obviously juvenile. To say the tank was filthy is a huge
understatement. It had floating dead cockroaches, clumps of what looked
like pond scum, sheets of algae peeling off the inside of the tank,
decomposing fish at the bottom of the tank, and so much floating
I-don't-even-know-what-but-I-suspect-fish-poop that I could barely
see the inhabitants of the tank.
In cleaning it out, I got a nice big splash of this disgusting water in
my mouth. It was certainly gross, but it is potentially harmful to my
health as well?
<There are two ways to answer this. In theory yes, aquarium water
can carry salmonella bacteria, and salmonella bacteria can cause
stomach upsets of varying severity. In practise, aquarium water rarely
causes health problems
for people with competent immune systems. Indeed, exposure to such
bacteria may even help enhance your immune system. But with that said,
I'm a doctor of palaeontology, not medicine, so my comments here
aren't anything more than personal opinion. Do I worry about
swallowing fish tank water? No, never have done. But if you're at
all concerned, you really should speak to a qualified medical
The guppies seem fine and happy now, despite the emergency tank
cleaning and care by me, a total beginner.
<Enjoy the hobby! A 10 gallon tank is a bit small for Guppies, and I
fear you're going to have some fighting before too long, but if
you're lucky and add lots of floating plants, you might be
Any advice (or reassurance!) you could give would be most
Re: Fish water is yuck, but is it actually
Thank you so very much Neale.
I'm a pretty healthy person (except for a touch of
paranoia/anxiety, apparently) so I think I will wait to see if I
develop any symptoms. If I do, I'll head to the doctor, but if not,
I'll take this experience as a lesson to 1) not splash myself in
the face with nasty water, and 2) never ever let a tank get so dirty
that I immediately think I'm going to die a horrible death with
exposure to the water.
<Honestly, getting sick from your fish tank isn't that common.
Dogs and cats are surely more problematic once you start factoring in
things like fleas and allergies. And of course you're FAR more
likely to contract pathogens from human beings around you simply
because they're more likely to carry bacteria and viruses specific
to our kind. There's an old saying among medics that 50% of staying
healthy is keeping clean, and 50% is getting dirty. In other words,
staying away from disease-causing organisms is no more important than
developing your immune system by being exposed to pathogens over the
years. The tricky bit is knowing when to isolate yourself to pathogens
and when to expose yourself to them! Personally, I wouldn't worry
too much either way. Be sensible around your aquarium, but don't
I'm doing all the reading I can about guppies on WWM now, and I am
amazed by the amount of information posted. The little guys have a
better chance of a happy, pleasant life with each new article I read,
certainly deserve after such an awful time in that tank.
<Glad to hear this.>
Thank you again,
Re: Fish water is yuck, but is it actually harmful?? Guppy
sys., hlth. 3/18/10
Good morning/afternoon, crew!
It's Amy here again, with one more question regarding my new guppy
I was lucky enough to come across a 55 gal tank for sale, and it will--
once it's cycled properly, of course-- be the new home for my
guppies and possibly a few Platies.
<If you have a mature aquarium already, you can cycle instantly.
Move the existing filter to the new tank, make sure the water chemistry
and water temperature aren't too different, and off you go! The
bacteria will happily spread to a second filter if you decide to buy
another filter for this tank. Leave the two filters running together
for, say, 6 weeks, and then remove the small filter from the original
tank. You should find the new filter takes up the slack without
problems. Better yet, you can keep some fish in the new tank all the
time, so long as the number of fish in the new tank isn't much more
than the number of fish in the original, smaller tank.>
I know the guppies breed like crazy, and figure that this size of tank
will give them enough room to have their offspring without having to
worry too much about overcrowding, at least right away.
<Indeed. It's a good idea to either decide whether you want to
remove surplus fish and sell them (in which case keep Guppies of all
one variety, so you get worthwhile fry) or else opt for some biological
control in the form of fish that eat fry (such as Angelfish).>
In closer inspection of the juvenile fish I was given yesterday, I
noticed that one of the young ones has what can only be described as a
He's got a humpback and is noticeably shorter than the rest of the
He seems fine otherwise; that is, he eats just like the others, and
seems to be just as active as well.
<Very, very common. Sometimes you get higher numbers of deformities
because the females aren't getting a good diet or being kept warm
enough, but normally livebearers produce deformed fry because
Despite the fact that I am becoming fond of him, I want to be a
responsible fish owner, and do not want to allow him to pass on a
deformity to any potential offspring. Is a spinal deformity a
hereditary condition, or is it possible that he was born into such foul
conditions that he acquired this humpback from his environment?
<Could be either. A poor environment can cause females to produce
higher than average numbers of deformities, just as with humans. But
usually, such deformities are indeed genetic.>
I'd rather not kill him (like I said, I'm fond of the little
guy, especially since he's been through so much!) so I was thinking
I could put him into the old ten gallon aquarium by himself, or
possibly with another small, non-related fish to ensure he doesn't
<Definitely an option. I think most experienced aquarists have done
this sort of thing at one time or another, setting up a special home
for a one-eyed fish or whatever that appeals to their emotions. That
said, there may be other faulty genes at work here. If the fish is
swimming and feeding fine, then it may do well; but if it struggles to
swim and can't feed normally, then it may not live for terribly
If he has already bred, and passed on the deformity, what should I do
with the fry?
<Male Guppies won't breed until they're about 2, nearer 3
months old. Of course if the fish has mated with a female, and you do
have more deformed fry on the way, then a certain amount of culling is,
unfortunately, part of
Any suggestions would be truly appreciated. Thank you again for all of
your help on my new fishy friends!
Deformed Guppy tail and fin
01/01/2006 Hello, thank you for providing such a great informative
site. <Welcome> I breed guppies with the intention of trying to
attract some of our beautiful water birds in the area that I
live in among the hills and bushland of Perth Western Australia.
<Interesting> I have only been breeding them for 3 months,
starting with 4 males and 14 females I know have over 500 fry and
dozens being born each day. Among my fry I notice some of them when
around 3 weeks old seem to have narrow tails and what seems to be no
dorsal or anal fins, they may be there and too small to see, however
the tail is narrow and seems to effect their swimming. <Yes... good
description... these are "throw backs"... more wild-type
characteristics... what guppy breeders for the ornamental trade would
treat as culls> I have also noticed among my dead guppies they
mostly if not all seem to be the ones with the deformed tails. It is
very hard to see what sex they are, they seem if they get a little
older to be trying to be a male but when they approach a female they
seem to swim backward when near her as if trying to manoeuvre closer.
My first fry were born around 6 weeks ago, the eldest of them seem well
formed and no problems, as yet my oldest fry with the problem I
describe is around 3-4 weeks. I would appreciate any suggestions of
help. Is this an American based web site? <Is more American than
not, the responders being in (most of the time) and of American
citizenry... but we are "human" oriented... respond to, seek
to help all... regardless of country of origin/nationality, any other
"other" quality> Thank you, Anne <Well, you might well
be able to reduce the incidence of deformity... mostly by breeding,
culling in more controlled circumstances (aquariums) and releasing the
"better-shaped" young into your grow out pond... Your water
quality might well play a role here as well as nutrition... Guppies
prefer hard, alkaline water for instance. Lastly, a note to encourage
your care in not allowing these livebearers to "get loose" to
the wild. This species is problematical in several parts of the world
as an exotic contaminant. Cheers, Bob Fenner>
Re Deformed Guppy tail and fin 01/01/2006 now 1/10/06
Thanks Bob for your reply to my questions. So far the fish born with
the deformed tails all seem to die at around 3-4 weeks, yesterday I
started to try to separate some of the young males and found for the
first time one deformed fish that looked like a male, it is the first
time I had been able to tell the sex of a deformed fish. I notice today
he was dead, they do seem to have problems in swimming in the same
fashion as a normal fish. I will make sure they don't breed. Thank
you also for the warning about letting the Guppies loose in the wild, I
won't do that as I know they can be a pest. <Ah, good> Do you
have any hints or suggestions on sexing fish. I have no
problem in seeing male or female it is the amount I need to separate
and it seems to stress them out when I take them out of their tank and
keep them in a small glass long enough to get a good look at them, they
seem to want to stay close to the bottom of the glass. It is very time
consuming and unless I can remove all of my adult males I can see there
is no other way to stop fry from being born. <Mmm, really just a
matter of practice... perhaps catching them one at a time, placing in a
clear trap/container, using a magnifying glass will help> My large
tank is around 4 feet long by 2 feet deep and with only 12
females and 3 adult males with at least 6 males near maturity or close
to fully mature. I have over 600 fry in other tanks and all sizes from
new born up to adult in the large tank, <Wowzah... most breeders use
ten, fifteen, maybe twenty gallon tanks... hard to catch in larger...
to put this mildly> I only catch newborn fry when they are at the
top of the tank, below there seem to be several hundred among the
plants. I feel a need to stop them breeding and catching the
males is about all I can think of Any suggestions would be greatly
appreciated.. Regards, and thank you. Anne. <You could be
single-handedly, the principal reason for a "renaissance" in
pet-fish keeping in your area... by spreading the wealth, giving some
guppies to neighbors! Bob Fenner>
Re: Deformed Guppy tail and fin 1/11/06 Hi Bob.
<Anne> "<Mmm, really just a matter of practice... perhaps
catching them one at a time, placing in a clear trap/container, using a
magnifying glass will help>" Thanks that is what I have been
doing, I just knew I was asking an impossible question. One at a time
is very time consuming, I will just have to keep on plugging along, I
thank you again for your help. Regards, Anne. <Life to you my
friend. Bob Fenner>
My Female Guppy needs serious help! Hi! My
name is Eunhae (oon-hay) and I have 2 male guppies and 2 female guppies
(I think they are Mosaic). I also have 10 fry. 1 of them got squished
somehow between the rocks at the bottom of the aquarium and died. It
was quite sad. I have a 5 gal tank that I keep the adults in and a 1.66
gal tank that I keep the fry in. Well anyhow, 1 of my female guppy
(Molly) is acting quite strange lately. Her eyes are mostly all black
(so it doesn't have a white ring around her eye). <Happens...
Genetic> She gave birth to the fry about a 1 1/2 week ago. She stays
at the bottom of the tank and if she does move, she swims with her
belly up. She keeps going around and around continually if she starts.
It makes me quite dizzy just watching her. My other 3 guppies used to
hang around with her but now they stay far away from her. And even
once, Molly, tried to attack one of the male guppies (James). Is she
going crazy? <Mmmm, no> It definitely seems like it. Molly also
doesn't eat much anymore. She stopped eating about 5 days ago. And
sometimes she just floats around the tank then suddenly rushes to the
bottom. Do you think something's wrong with the water? <Maybe,
but doubtful if your other guppies are not affected> And isn't
the male guppy suppose to be aggressive to the female instead of the
opposite? <Generally, yes> I have so many questions. I just
discovered your website and as I was browsing I found out that I can
ask you questions. Please write back as soon as possible. I really
don't want Molly to die. She used to be one of my favorites when I
got the guppies. Thanks! Eunhae <The one fish is likely
defective, but not otherwise diseased. Do keep your eye on it and
remove should it perish. Bob Fenner>
A Guppy named Molly Hi! This is Eunhae. I
wrote to you before about my female guppy, Molly, that was acting
really crazy. Well, the interesting thing is I thought that she would
definitely die for sure, but after a day or more she started eating
again and now she's healthy. She eats like the other fish and she
doesn't just float around anymore. She swims properly and stuff.
Now one of her fry that's in the other tank (separate from the
adults) has a weird body shape. It acts fine and eats okay too though.
It's lower body part (the part where it starts to be clear to the
tail) is pointing upward. So his/her body looks like an angle at a 165
degrees. It's really funny looking. Do you think it's something
that will keep happening if the fish is a she and she lays babies? I
hope not. Well, thanks! Eunhae <Glad your fish is better. The fry
problem may be genetic in nature. If so you should not breed her.
Always breed healthy stock only. Most breeders would cull this fry. No
one wants generations of deformed fish. Don>