misterious fish in New aquarium

[Hari]

Hi,

I set up a new 10 gallon aquarium a month ago. I have 1 black molly, 2
male yellow guppies , 1 yellow Balloon belly molly, 1 red platy and a
albino catfish.

Suddenly There are some new fishes ( very small 2-3 mm size). they are
hiding in the gravels most of the time. I don't know how they got
there. Also, I'm worried that they will be eaten by others.
Any idea how this happened ?

Thanks in Advance.

-hharan

[Rick]

"Hari" > wrote in message
om...
> Hi,
>
> I set up a new 10 gallon aquarium a month ago. I have 1 black molly, 2
> male yellow guppies , 1 yellow Balloon belly molly, 1 red platy and a
> albino catfish.
>
> Suddenly There are some new fishes ( very small 2-3 mm size). they are
> hiding in the gravels most of the time. I don't know how they got
> there. Also, I'm worried that they will be eaten by others.
> Any idea how this happened ?
>
> Thanks in Advance.
>
> -hharan

sure it's called breeding. You have with the exception of the Cory, a tank
of live bearers. You can expect fry about once a month. Even if you have no
males the females may have come carrying fry from where ever you got them.
The Mollies and Platy's will produce hybrid fry. If you want to save some of
the fry you will have to provide them with some hiding areas and in the case
of livebearers plants are the best choice. Get some floating plants like
hornwort or watersprite and a few will survive out of each batch. Keep in
mind that each female will drop about once a month. If you have say 4
females and two fry live from each you will have 8 new fish each month.
That's how I ended up with 30 tanks.

Rick

[kclmymy]

Rick > wrote in message
news:993Jb.900546$6C4.335210@pd7tw1no...
>
>
> sure it's called breeding. You have with the exception of the Cory, a
tank
> of live bearers. You can expect fry about once a month. Even if you have
no
> males the females may have come carrying fry from where ever you got them.
> The Mollies and Platy's will produce hybrid fry. If you want to save some
of
> the fry you will have to provide them with some hiding areas and in the
case
> of livebearers plants are the best choice. Get some floating plants like
> hornwort or watersprite and a few will survive out of each batch. Keep in
> mind that each female will drop about once a month. If you have say 4
> females and two fry live from each you will have 8 new fish each month.
> That's how I ended up with 30 tanks.
>
> Rick
>
That's the reason I seperate my M/F swordtail.

Wow, 30 tanks !!! How's your w/c schedule ? Where do you find rooms for 30 ?
I can't even get my wife to agree to my 4th :-(

kclmymy

[Hari]

Oh!. Thanks. I sure don't want that many fishes. But I feel bad
letting them die that way :-(.


"Rick" > wrote in message news:<993Jb.900546$6C4.335210@pd7tw1no>...
> "Hari" > wrote in message
> om...
> > Hi,
> >
> > I set up a new 10 gallon aquarium a month ago. I have 1 black molly, 2
> > male yellow guppies , 1 yellow Balloon belly molly, 1 red platy and a
> > albino catfish.
> >
> > Suddenly There are some new fishes ( very small 2-3 mm size). they are
> > hiding in the gravels most of the time. I don't know how they got
> > there. Also, I'm worried that they will be eaten by others.
> > Any idea how this happened ?
> >
> > Thanks in Advance.
> >
> > -hharan
>
> sure it's called breeding. You have with the exception of the Cory, a tank
> of live bearers. You can expect fry about once a month. Even if you have no
> males the females may have come carrying fry from where ever you got them.
> The Mollies and Platy's will produce hybrid fry. If you want to save some of
> the fry you will have to provide them with some hiding areas and in the case
> of livebearers plants are the best choice. Get some floating plants like
> hornwort or watersprite and a few will survive out of each batch. Keep in
> mind that each female will drop about once a month. If you have say 4
> females and two fry live from each you will have 8 new fish each month.
> That's how I ended up with 30 tanks.
>
> Rick

[KEITH JENNINGS]

"kclmymy" > wrote in message
...
> Rick > wrote in message
> news:993Jb.900546$6C4.335210@pd7tw1no...
> >
> >
> > sure it's called breeding. You have with the exception of the Cory, a
> tank
> > of live bearers. You can expect fry about once a month. Even if you have
> no
> > males the females may have come carrying fry from where ever you got
them.
> > The Mollies and Platy's will produce hybrid fry. If you want to save
some
> of
> > the fry you will have to provide them with some hiding areas and in the
> case
> > of livebearers plants are the best choice. Get some floating plants like
> > hornwort or watersprite and a few will survive out of each batch. Keep
in
> > mind that each female will drop about once a month. If you have say 4
> > females and two fry live from each you will have 8 new fish each month.
> > That's how I ended up with 30 tanks.
> >
> > Rick
> >
> That's the reason I seperate my M/F swordtail.
>
> Wow, 30 tanks !!! How's your w/c schedule ? Where do you find rooms for 30
?
> I can't even get my wife to agree to my 4th :-(
>
> kclmymy
>
At one point, I was up to 18 tanks. 6 months of maintenence for all 18
showed me the error of my ways. I'm down to 3 tanks, and much happier for
it. Now I even have time to eat and sleep.
=)
Keith J.

[Dinky]

"Hari" > wrote in message
om...
> Oh!. Thanks. I sure don't want that many fishes. But I feel bad
> letting them die that way :-(.
>
Don't. It's nature at it's purest. You set up the tank to try and recreate
a bit of nature, and that's what has happened.

billy

[Rick]

"kclmymy" > wrote in message
...
> Rick > wrote in message
> news:993Jb.900546$6C4.335210@pd7tw1no...
> >
> >
> > sure it's called breeding. You have with the exception of the Cory, a
> tank
> > of live bearers. You can expect fry about once a month. Even if you have
> no
> > males the females may have come carrying fry from where ever you got
them.
> > The Mollies and Platy's will produce hybrid fry. If you want to save
some
> of
> > the fry you will have to provide them with some hiding areas and in the
> case
> > of livebearers plants are the best choice. Get some floating plants like
> > hornwort or watersprite and a few will survive out of each batch. Keep
in
> > mind that each female will drop about once a month. If you have say 4
> > females and two fry live from each you will have 8 new fish each month.
> > That's how I ended up with 30 tanks.
> >
> > Rick
> >
> That's the reason I seperate my M/F swordtail.
>
> Wow, 30 tanks !!! How's your w/c schedule ? Where do you find rooms for 30
?
> I can't even get my wife to agree to my 4th :-(
>
> kclmymy
> >
>
a lot of the tanks are smaller. I have a 77 planted tank and a 50 Hex in my
livingroom. I have a 75 South American and a 66 African cichlid in my main
rec room. In what used to be a bedroom in my basement I have a rack of 6 x
15 g, along one wall, then a seating area for two chairs, then a rack with a
48 long containing North American Alabama long ears and under that two 20 g
.. A 8' rack along the other wall containing a 40, 2 x 33, 1 x 25 and the
rest of the tanks on that rack are 7 x 10 g , along with a number of smaller
6, 5 and 3 gallon breeder tanks. I change water on all tanks every two weeks
with the exception of my planted tank which I change 50% weekly at the
moment as I am dry dosing ferts. Oh yeah, have a 20 on a separate stand with
some Convicts in. I have a r/o system in my house which comes in handy for
my soft water fish ( I have lots of Corydoras) and I ran a line from the
kitchen to the basement laundry room where the waste water goes into two
large containers. I couldn't stand wasting the amount of water a r/o system
uses without doing something with it. I use the waste water for my water
changes.

Rick

Rick

[Rick]

"KEITH JENNINGS" > wrote in message
...
>
> "> At one point, I was up to 18 tanks. 6 months of maintenence for all 18
> showed me the error of my ways. I'm down to 3 tanks, and much happier for
> it. Now I even have time to eat and sleep.
> =)
> Keith J.
>
>
the smaller tanks can get a bit tedious but I don't spend a tremendous
amount of time on them and I try to arrange my time so I do a number of
tanks one day and others another day but I do know the feeling.. I also
don't drain and refill tanks individually which makes having most of my
tanks in one room quite handy. I use a gravel vac hooked up to enough drain
line to reach my basement floor drain. I also have a linear piston pump
running all those tanks in the one room so I just shut off the valves, drain
say a rack of 6 x 15 one after the other and then I reverse the drain line
hooking up the drain end to a pond pump which is in my waster containers,
plug it in and refill all the tanks at one time. I am presently making a
siphon system with PVC pipe that will have a drain line cut for the right
size for the various tanks that will take out say 20 -25% of the water. Hook
the PVC drain line onto one tank , sit down and have a coffee and when it
starts to suck air simply move it to the next tank. Gotta make the job as
easy as possible. I gotta tell ya that the linear pump hooked up to ATI
sponge filters has made my life a lot easier.

Rick

[TYNK 7]

>Subject: misterious fish in New aquarium
>From: (Hari)
>Date: 1/1/2004 5:41 PM Central Standard Time
>Message-id: >
>
>Hi,
>
>I set up a new 10 gallon aquarium a month ago. I have 1 black molly, 2
>male yellow guppies , 1 yellow Balloon belly molly, 1 red platy and a
>albino catfish.
>
>Suddenly There are some new fishes ( very small 2-3 mm size). they are
>hiding in the gravels most of the time. I don't know how they got
>there. Also, I'm worried that they will be eaten by others.
>Any idea how this happened ?
>
>Thanks in Advance.
>
>-hharan
>

One of your live bearing fish had young.
No big mystery. = )
Also, live bearers can hold sperm inside their bodies and have up to 3 batched
of fry..from one mating!

[TYNK 7]

>Subject: Re: misterious fish in New aquarium
>From: "kclmymy"
>Date: 1/1/2004 11:21 PM Central Standard Time
>Message-id: >
>
>Rick > wrote in message
>news:993Jb.900546$6C4.335210@pd7tw1no...
>>
>>
>> sure it's called breeding. You have with the exception of the Cory, a
>tank
>> of live bearers. You can expect fry about once a month. Even if you have
>no
>> males the females may have come carrying fry from where ever you got them.
>> The Mollies and Platy's will produce hybrid fry. If you want to save some
>of
>> the fry you will have to provide them with some hiding areas and in the
>case
>> of livebearers plants are the best choice. Get some floating plants like
>> hornwort or watersprite and a few will survive out of each batch. Keep in
>> mind that each female will drop about once a month. If you have say 4
>> females and two fry live from each you will have 8 new fish each month.
>> That's how I ended up with 30 tanks.
>>
>> Rick
>>
>That's the reason I seperate my M/F swordtail.
>

Don't forget...when in a one sex community, swords can change their sex. = )

[NetMax]

"Dinky" > wrote in message
link.net...
>
> "Hari" > wrote in message
> om...
> > Oh!. Thanks. I sure don't want that many fishes. But I feel bad
> > letting them die that way :-(.
> >
> Don't. It's nature at it's purest. You set up the tank to try and
recreate
> a bit of nature, and that's what has happened.
>
> billy

An argument could be made that most of our tanks are very far from
'nature's ways' and that they rely on the wisdom and benevolence of the
'gods' who feed them and maintain their environment, (but I'm not the
type to argue ;~)

If there was a reasonable amount of rockwork, plants and gallonage for a
% of the fry to survive, and this % was similar to what occurs in their
natural habitat, _then_ you would strengthen the argument for 'nature at
it's purest'. A newborn fry with 5 or 6 predators in a glass box of 10g
might be pushing the 'nature' story
a t i n y bit ;o)

I completely agree with billy about recreating a bit of nature, - it's
our success at it that varies a lot.

NetMax

[kclmymy]

TYNK 7 > wrote in message
...
> >Subject: Re: misterious fish in New aquarium
> >From: "kclmymy"
> >Date: 1/1/2004 11:21 PM Central Standard Time
> >Message-id: >
> >
> >Rick > wrote in message
> >That's the reason I seperate my M/F swordtail.
> >
>
> Don't forget...when in a one sex community, swords can change their sex.
= )

Never know that can happen !

I separated the M/F for almost 3 generations yet no sex change ! Will love
to know more.

Cheers

kclmymy

[Liisa Sarakontu]

(TYNK 7) wrote in
:

> Don't forget...when in a one sex community, swords can change their
> sex. = )

As far as I know, that's not true.

Liisa

[KEITH JENNINGS]

Some varieties of sal****er fish can change their sex , and some freshwater
fish have the sex ratio of their fry determined by temperature or pH . But I
haven't heard of freshwater fish changing sexes...

"Liisa Sarakontu" > wrote in message
. ..
> (TYNK 7) wrote in
> :
>
> > Don't forget...when in a one sex community, swords can change their
> > sex. = )
>
> As far as I know, that's not true.
>
> Liisa
>
>

[TYNK 7]

>Subject: Re: misterious fish in New aquarium
>From: Liisa Sarakontu
>Date: 1/7/2004 2:17 AM Central Standard Time
>Message-id: >
>
(TYNK 7) wrote in
:
>
>> Don't forget...when in a one sex community, swords can change their
>> sex. = )
>
>As far as I know, that's not true.
>
>Liisa

Oh it is. = )
I don't know if they're fertile or not, but they do change.

[TYNK 7]

>Subject: Re: misterious fish in New aquarium
>From: "KEITH JENNINGS"
>Date: 1/7/2004 2:48 AM Central Standard Time
>Message-id: >
>
>Some varieties of sal****er fish can change their sex , and some freshwater
>fish have the sex ratio of their fry determined by temperature or pH . But I
>haven't heard of freshwater fish changing sexes...

(snipped)
This is when we need to Jim come in and explain every little detail about this.
NetMax, can you help?
I forget whether it's a female changes to male or vice versa. Also, if they're
able to breed or not.
I had this happen with Swods so many years ago (I was a kid), that I can't
remember which way it went. I was also too young to think about keeping records
back then (who knew this would turn into a lifelong hobby) = )

[Sajjad Lateef]

On Wed, 07 Jan 2004 18:33:01 +0000, TYNK 7 wrote:

>>Subject: Re: misterious fish in New aquarium
>>From: "KEITH JENNINGS"
>>Date: 1/7/2004 2:48 AM Central Standard Time
>>Message-id: >
>>
>>Some varieties of sal****er fish can change their sex , and some freshwater
>>fish have the sex ratio of their fry determined by temperature or pH . But I
>>haven't heard of freshwater fish changing sexes...
>
> (snipped)
> This is when we need to Jim come in and explain every little detail about this.
> NetMax, can you help?
> I forget whether it's a female changes to male or vice versa. Also, if they're
> able to breed or not.
> I had this happen with Swods so many years ago (I was a kid), that I can't
> remember which way it went. I was also too young to think about keeping records
> back then (who knew this would turn into a lifelong hobby) = )

I'm not NetMax, but, if you allow me ...

Yes, Freshwater Livebearers of Genus Xiphophorus (ex: Swordtails)
change sex. Generally, a female changes into a male when there
is a paucity of males. This is very well documented in almost every
book you pick up on livebearers.

Sajjad

[Mike Edwardes]

In article >,
Sajjad Lateef > wrote:

> On Wed, 07 Jan 2004 18:33:01 +0000, TYNK 7 wrote:
>
> >>Subject: Re: misterious fish in New aquarium
> >>From: "KEITH JENNINGS"
> >>Date: 1/7/2004 2:48 AM Central Standard Time
> >>Message-id: >
> >>
> >>Some varieties of sal****er fish can change their sex , and some freshwater
> >>fish have the sex ratio of their fry determined by temperature or pH . But
> >>I
> >>haven't heard of freshwater fish changing sexes...
> >
> > (snipped)
> > This is when we need to Jim come in and explain every little detail about
> > this.
> > NetMax, can you help?
> > I forget whether it's a female changes to male or vice versa. Also, if
> > they're
> > able to breed or not.
> > I had this happen with Swods so many years ago (I was a kid), that I can't
> > remember which way it went. I was also too young to think about keeping
> > records
> > back then (who knew this would turn into a lifelong hobby) = )
>
> I'm not NetMax, but, if you allow me ...
>
> Yes, Freshwater Livebearers of Genus Xiphophorus (ex: Swordtails)
> change sex. Generally, a female changes into a male when there
> is a paucity of males. This is very well documented in almost every
> book you pick up on livebearers.

Yes, it is, but it is not true. As said, this phenomenon occurs
regularly in some marine fish but not in freshwater fish. In swordtails
(Xiphophorus) and some other livebearers, the apparent change is always
female to male. This is caused by late developing males which can be
phenotypically female for years in some cases which eventually develop
into their genetically determined male form. The cause is not known,
but it has fooled people for years, leading to that old joke, "How do
you tell what sex a fish is? Take it's genes off!"

Mike.
--
Mike Edwardes Tropicals
http://mike-edwardes.members.beeb.net

[TYNK 7]

>Subject: Re: misterious fish in New aquarium
>From: Sajjad Lateef
>Date: 1/7/2004 1:29 PM Central Standard Time
>Message-id: >
>
>On Wed, 07 Jan 2004 18:33:01 +0000, TYNK 7 wrote:
>
>>>Subject: Re: misterious fish in New aquarium
>>>From: "KEITH JENNINGS"
>>>Date: 1/7/2004 2:48 AM Central Standard Time
>>>Message-id: >
>>>
>>>Some varieties of sal****er fish can change their sex , and some freshwater
>>>fish have the sex ratio of their fry determined by temperature or pH . But
>I
>>>haven't heard of freshwater fish changing sexes...
>>
>> (snipped)
>> This is when we need to Jim come in and explain every little detail about
>this.
>> NetMax, can you help?
>> I forget whether it's a female changes to male or vice versa. Also, if
>they're
>> able to breed or not.
>> I had this happen with Swods so many years ago (I was a kid), that I can't
>> remember which way it went. I was also too young to think about keeping
>records
>> back then (who knew this would turn into a lifelong hobby) = )
>
>I'm not NetMax, but, if you allow me ...
>
>Yes, Freshwater Livebearers of Genus Xiphophorus (ex: Swordtails)
>change sex. Generally, a female changes into a male when there
>is a paucity of males. This is very well documented in almost every
>book you pick up on livebearers.
>
>Sajjad
>

Thank you! = )

[Liisa Sarakontu]

(TYNK 7) wrote in news:20040107133028.04265.00002517@mb-
m29.aol.com:

> Oh it is. = )
> I don't know if they're fertile or not, but they do change.

It is not true sex change. Two different cases of "false sex change" are
known to happen in swords, but the sex doesn't change in either case:

1. Late male. Some males mature and develop gonopod and sword rather early,
other keep on looking like females until they are months, perhaps even a
year old and only then show their real sex. They grow on average larger
than early males. This is not sex cnahge, although it might look like it.

2. Females with hormonal problems. Female, often rather old animal, can
loose its hormonal balance and as the amount of male hormon (testosterone)
gets too large, a female can develop male-looking sword and even start
acting like male. But as internal sex organs are missing, it isn't a real
male. Sex doesnät change in this case either.

Liisa

[~misfit~]

Mike Edwardes wrote:
> In article >,
> Sajjad Lateef > wrote:
>
>> On Wed, 07 Jan 2004 18:33:01 +0000, TYNK 7 wrote:
>>
>>>> Subject: Re: misterious fish in New aquarium
>>>> From: "KEITH JENNINGS"
>>>> Date: 1/7/2004 2:48 AM Central Standard Time
>>>> Message-id: >
>>>>
>>>> Some varieties of sal****er fish can change their sex , and some
>>>> freshwater fish have the sex ratio of their fry determined by
>>>> temperature or pH . But I
>>>> haven't heard of freshwater fish changing sexes...
>>>
>>> (snipped)
>>> This is when we need to Jim come in and explain every little detail
>>> about this.
>>> NetMax, can you help?
>>> I forget whether it's a female changes to male or vice versa. Also,
>>> if they're
>>> able to breed or not.
>>> I had this happen with Swods so many years ago (I was a kid), that
>>> I can't remember which way it went. I was also too young to think
>>> about keeping records
>>> back then (who knew this would turn into a lifelong hobby) = )
>>
>> I'm not NetMax, but, if you allow me ...
>>
>> Yes, Freshwater Livebearers of Genus Xiphophorus (ex: Swordtails)
>> change sex. Generally, a female changes into a male when there
>> is a paucity of males. This is very well documented in almost every
>> book you pick up on livebearers.
>
> Yes, it is, but it is not true. As said, this phenomenon occurs
> regularly in some marine fish but not in freshwater fish. In
> swordtails (Xiphophorus) and some other livebearers, the apparent
> change is always female to male. This is caused by late developing
> males which can be phenotypically female for years in some cases
> which eventually develop into their genetically determined male form.
> The cause is not known, but it has fooled people for years, leading
> to that old joke, "How do you tell what sex a fish is? Take it's
> genes off!"

I disagree. I've had a big female Xiphophorus that had previously given
birth several times 'turn male' when there were no males in the tank. She/he
was fertile and impregnated several other females. The fry born of this
union were of both sexes indicating that she/he had a 'Y' chromosome. Maybe
the true story is that, in a few males, the 'Y' chromosome is weak maybe and
lies dormant, maybe due to other males producing a pheromone or simply
testosterone. When the source of the inhibiting compound is removed they
change to the males they were supposed to be. It still amazes me as a
biologist that they can function sexually/reproductively as both female and
male at different stages of their lives.

--
~misfit~

[NetMax]

"TYNK 7" > wrote in message
...
> >Subject: Re: misterious fish in New aquarium
> >From: "KEITH JENNINGS"
> >Date: 1/7/2004 2:48 AM Central Standard Time
> >Message-id: >
> >
> >Some varieties of sal****er fish can change their sex , and some
freshwater
> >fish have the sex ratio of their fry determined by temperature or pH .
But I
> >haven't heard of freshwater fish changing sexes...
>
> (snipped)
> This is when we need to Jim come in and explain every little detail
about this.
> NetMax, can you help?
> I forget whether it's a female changes to male or vice versa. Also, if
they're
> able to breed or not.
> I had this happen with Swods so many years ago (I was a kid), that I
can't
> remember which way it went. I was also too young to think about keeping
records
> back then (who knew this would turn into a lifelong hobby) = )

AFAIK, the changing of sex in livebearers is not true. The external
characteristics can change (and this is not uncommon among many species),
and undeveloped males can make a late appearance, but their internal
organs (males & females) are different at birth, so their ability to
sexually produce other than what they were born to do, would be doubtful.

Having said that, remember the 'aquaria rule', that for every rule, there
is always exceptions ;~), so who knows?
NetMax

[Sajjad Lateef]

On Thu, 08 Jan 2004 05:34:00 +0000, TYNK 7 wrote:

>>Subject: Re: misterious fish in New aquarium
>>From: Sajjad Lateef >
>>On Wed, 07 Jan 2004 18:33:01 +0000, TYNK 7 wrote:
>>>>Subject: Re: misterious fish in New aquarium
>>>>From: "KEITH JENNINGS"
>>>>Some varieties of sal****er fish can change their sex , and some freshwater
>>>>fish have the sex ratio of their fry determined by temperature or pH . But
>>I
>>>>haven't heard of freshwater fish changing sexes...
>>>
>>> (snipped)
>>> This is when we need to Jim come in and explain every little detail about
>>this.
>>> NetMax, can you help?
>>> I forget whether it's a female changes to male or vice versa. Also, if
>>they're
>>> able to breed or not.
>>> I had this happen with Swods so many years ago (I was a kid), that I can't
>>> remember which way it went. I was also too young to think about keeping
>>records
>>> back then (who knew this would turn into a lifelong hobby) = )
>>
>>I'm not NetMax, but, if you allow me ...
>>
>>Yes, Freshwater Livebearers of Genus Xiphophorus (ex: Swordtails)
>>change sex. Generally, a female changes into a male when there
>>is a paucity of males. This is very well documented in almost every
>>book you pick up on livebearers.
>>
>>Sajjad
>>
>
> Thank you! = )


Both Liisa and NetMax seem to think this is not true sex change.
I may have been wrong here. But, I'll confirm and get back to you.

Sajjad

[TYNK 7]

>Subject: Re: misterious fish in New aquarium
>From: Liisa Sarakontu
>Date: 1/8/2004 12:29 AM Central Standard Time
>Message-id: >
>
(TYNK 7) wrote in news:20040107133028.04265.00002517@mb-
>m29.aol.com:
>
>> Oh it is. = )
>> I don't know if they're fertile or not, but they do change.
>
>It is not true sex change. Two different cases of "false sex change" are
>known to happen in swords, but the sex doesn't change in either case:
>
>1. Late male. Some males mature and develop gonopod and sword rather early,
>other keep on looking like females until they are months, perhaps even a
>year old and only then show their real sex. They grow on average larger
>than early males. This is not sex cnahge, although it might look like it.
>
>2. Females with hormonal problems. Female, often rather old animal, can
>loose its hormonal balance and as the amount of male hormon (testosterone)
>gets too large, a female can develop male-looking sword and even start
>acting like male. But as internal sex organs are missing, it isn't a real
>male. Sex doesnät change in this case either.
>
>Liisa
>
>

I would have to assume you've never had this happen in one of your tanks.
I have.
I did a lot of thinking because I couldn't remember which sex changed, but I
did finally remember it being a female that had had fry, changed to a male and
developed a sword too.
Whether or not it was fertile, I do not know.
This was a fully grown, working parts and all, female that went to what would
appear to be a male. Gonopdium (sp?) and sword to boot. Sperm????Don't know,
didn't ask and I'm surely not going to get a sample, lol. = )~

[Sajjad Lateef]

Tynk,

Here is a response from Scott Davis - a knowledgeable aquarist
in the Chicago area - on sex change in Xiphophorus sp.
His entire email response has been copied here. My original
email question to him is below.

Please make your own conclusions.

From : Scott Davis
To : Sajjad Lateef
Date : Thu, 9 Jan 2004

Hey Sajjad!

This info is not the latest, but there was a study in Copeia
on swordtails a number of years ago considering the role of
different sized swordtails. There were those who started
showing their swords when they were small. Their body growth
slowed down precipitously. There is a correlation between sexing
out and body growth. But they were available to inseminate
females early on.

X. helleri females preferred the company of large males
(those big studs which sexed out last) because the big male
would keep the small sneaker males away (most of the time)
from her, allowing her to forage for more food and spend less
energy avoiding the sneakers - which could then be used for
fry and growth.

Sometimes sex changes have been claimed for fish which just
kept growing and growing and sexed out as males. Of course if
the big boys got picked off by predators, there were always
the sneakers willing to help with procreation.

John Dawes, in his (1991) book on livebearers notes that
there are a couple of genetic combinations whcih determine
sex. There are XY males, also W,X, and Y chromosomes. He further
mentions a Z chromosome (I know this sounds a tad like Dave
Barry.) Locations of specific genes on a chromosome may also be
a variable. I haven't described this well. (Come to tomorrow's
CKA meeting, I will lend you the book and bibliography.)

Toki-O Yamamoto has also discussed males and females which have
secondary characterists of the other gender, The person which
mentioned this to me went on to suggest that the researcher
felt that the livebearers were still functionally one gender
or another, just confusing to the observer.

However I also recieved a note from a correspondant suggesting
that in "Ichthyology" by Lagler, et. al. "Sex-reversed males
presumably bearing XX chromosomes have been noted in the guppy;
their genetic sex was female, their real sex, male.... when
one of these exceptional XX males was mated to an XX female,
all the resultant offspring were females."

I've not looked that up yet.

Aging livebearers may show the influence of a shifting hormonal
balance. There certainly are Poecilid photos of previously
functional females showing male traits such as larger fins, some
more color, a thickening of the first anal fin rays) However,
female guppies and mollies, platys, swordtails, variatus and
Poecilia actually lose a number of bones reaching from their
ribs to the anal fin when they develop female features. (There
is a drawing of this in the latest ALA Livebearers #179) That
allows the females to have room in an expanding gravid area
for fry.

Males need to keep that pelvic girdle of bones in order to move
the gonopodium around. That is why some livebearer experts
question whether a female could change to a functional male
because they still would not have the bone structure necessary
to effectively use a modified anal fin.

There are several articles in Ecology and Evolution of
Livebearering Fishes, a 1989 set of studies on Poecelids edited
by Gary K Meffe and Franklin F. Snelson Jr. which also address
some of these issues. I don't have it handy. (Interlibrary loan
probably could get you a copy in a couple of weeks.)

The Xiphphorus home page also has an on-line
bibliography. Haven't used it yet.

http://www.xiphophorus.org/biblio.htm

Much of this is not real recent, but maybe a start.

All the best!

Scott
>
> What is the latest scientific conclusion on the sex change in
> freshwater livebearers like Xiphophorus sp.?
>
> Is it true sex change? Is it considered an apparent sex change with
> late-developing males? Is it a change in hormone levels in females
> causing them to develop male-like characteristics?
>
> References would be great, if you have them.
>
> Thanks
> Sajjad

[coelacanth]

"Mike Edwardes" > wrote in message >
> Yes, it is, but it is not true. As said, this phenomenon occurs
> regularly in some marine fish but not in freshwater fish. In swordtails
> (Xiphophorus) and some other livebearers, the apparent change is always
> female to male. This is caused by late developing males which can be
> phenotypically female for years in some cases which eventually develop
> into their genetically determined male form. The cause is not known,
> but it has fooled people for years, leading to that old joke, "How do
> you tell what sex a fish is? Take it's genes off!"
>
> Mike.

I just had one of my one year-old "female" swordtails go male on
me and I was trying to explain what happened to the kids--they
were a little freaked out by the whole thing (could this happen
to them being the underlying theme, I'm sure ;). While trying
to convince them that Nature was wonderful and mysterious,
but their own personal anatomy was safe, I realized that
I don't understand this phenomenon. Just how is gender
determined in fish, anyway. Is it with sex chromosomes like in
bird and people or is it just the hormonal balance? If it's the
latter, then all fish are basically neuter and their endocrine system
determines gender, meaning that the is no "genetic determination".
Does anyone know about this?

And Mike, can you substantiate the assertion that it is one thing
in clownfish and marines and a different thing among FW
livebearerers? My friend, Mr Occham has a razor which says
this is unlikely. TIA.

-coelacanth

[Jim Morcombe]

Your wife won't agree to a fourth?

I sugest you take her to the next Aquarium club meeting and swap her for a
couple of cat-fish.

Jim


kclmymy > wrote in message
...
> Rick > wrote in message
> news:993Jb.900546$6C4.335210@pd7tw1no...
> >
> >
> > sure it's called breeding. You have with the exception of the Cory, a
> tank
> > of live bearers. You can expect fry about once a month. Even if you have
> no
> > males the females may have come carrying fry from where ever you got
them.
> > The Mollies and Platy's will produce hybrid fry. If you want to save
some
> of
> > the fry you will have to provide them with some hiding areas and in the
> case
> > of livebearers plants are the best choice. Get some floating plants like
> > hornwort or watersprite and a few will survive out of each batch. Keep
in
> > mind that each female will drop about once a month. If you have say 4
> > females and two fry live from each you will have 8 new fish each month.
> > That's how I ended up with 30 tanks.
> >
> > Rick
> >
> That's the reason I seperate my M/F swordtail.
>
> Wow, 30 tanks !!! How's your w/c schedule ? Where do you find rooms for 30
?
> I can't even get my wife to agree to my 4th :-(
>
> kclmymy
>
>
>
>
>
>

[Jim Morcombe]

What do you do about aging your water?

Jim


Rick > wrote in message
news:nimJb.913239$pl3.488288@pd7tw3no...
>
> "KEITH JENNINGS" > wrote in message
> ...
> >
> > "> At one point, I was up to 18 tanks. 6 months of maintenence for all
18
> > showed me the error of my ways. I'm down to 3 tanks, and much happier
for
> > it. Now I even have time to eat and sleep.
> > =)
> > Keith J.
> >
> >
> the smaller tanks can get a bit tedious but I don't spend a tremendous
> amount of time on them and I try to arrange my time so I do a number of
> tanks one day and others another day but I do know the feeling.. I also
> don't drain and refill tanks individually which makes having most of my
> tanks in one room quite handy. I use a gravel vac hooked up to enough
drain
> line to reach my basement floor drain. I also have a linear piston pump
> running all those tanks in the one room so I just shut off the valves,
drain
> say a rack of 6 x 15 one after the other and then I reverse the drain line
> hooking up the drain end to a pond pump which is in my waster containers,
> plug it in and refill all the tanks at one time. I am presently making a
> siphon system with PVC pipe that will have a drain line cut for the right
> size for the various tanks that will take out say 20 -25% of the water.
Hook
> the PVC drain line onto one tank , sit down and have a coffee and when it
> starts to suck air simply move it to the next tank. Gotta make the job as
> easy as possible. I gotta tell ya that the linear pump hooked up to ATI
> sponge filters has made my life a lot easier.
>
> Rick
>
>

[Jim Morcombe]

As part of the research we all need to go watch Jurasick Park again:)

I think it was female dimosaurs that turned into males because of the frog
DNA.


Jim


TYNK 7 > wrote in message
...
> >Subject: Re: misterious fish in New aquarium
> >From: "KEITH JENNINGS"
> >Date: 1/7/2004 2:48 AM Central Standard Time
> >Message-id: >
> >
> >Some varieties of sal****er fish can change their sex , and some
freshwater
> >fish have the sex ratio of their fry determined by temperature or pH .
But I
> >haven't heard of freshwater fish changing sexes...
>
> (snipped)
> This is when we need to Jim come in and explain every little detail about
this.
> NetMax, can you help?
> I forget whether it's a female changes to male or vice versa. Also, if
they're
> able to breed or not.
> I had this happen with Swods so many years ago (I was a kid), that I can't
> remember which way it went. I was also too young to think about keeping
records
> back then (who knew this would turn into a lifelong hobby) = )

[Jim Morcombe]

Actually NetMax is pretty much on target when he talks about the benevolent
'gods'.

Our breeding efforts produce species that are more tolerant to Nitrites,
temperature changes and so on with each generation.

Did you ever wander why it is so easy to catch the live bearers in your
comunity tank while the mouth brooders are so damn nimbile and tricky?
Think about it.

Jim


NetMax > wrote in message
...
>
> "Dinky" > wrote in message
> link.net...
> >
> > "Hari" > wrote in message
> > om...
> > > Oh!. Thanks. I sure don't want that many fishes. But I feel bad
> > > letting them die that way :-(.
> > >
> > Don't. It's nature at it's purest. You set up the tank to try and
> recreate
> > a bit of nature, and that's what has happened.
> >
> > billy
>
> An argument could be made that most of our tanks are very far from
> 'nature's ways' and that they rely on the wisdom and benevolence of the
> 'gods' who feed them and maintain their environment, (but I'm not the
> type to argue ;~)
>
> If there was a reasonable amount of rockwork, plants and gallonage for a
> % of the fry to survive, and this % was similar to what occurs in their
> natural habitat, _then_ you would strengthen the argument for 'nature at
> it's purest'. A newborn fry with 5 or 6 predators in a glass box of 10g
> might be pushing the 'nature' story
> a t i n y bit ;o)
>
> I completely agree with billy about recreating a bit of nature, - it's
> our success at it that varies a lot.
>
> NetMax
>
>

[kclmymy]

Hahaha. No, not cat-fish. I prefer some blue-eye. ;-))

kclmymy

Jim Morcombe > wrote in message
...
> Your wife won't agree to a fourth?
>
> I sugest you take her to the next Aquarium club meeting and swap her for a
> couple of cat-fish.
>
> Jim
>
>
> kclmymy > wrote in message
> ...
> > That's the reason I seperate my M/F swordtail.
> >
> > Wow, 30 tanks !!! How's your w/c schedule ? Where do you find rooms for
30
> ?
> > I can't even get my wife to agree to my 4th :-(
> >
> > kclmymy