# My herd of Platies has a sever case of pregnancy.



## RandomBoy

Hello sirs and madams. My brigade of Xiphophorus maculatus (four female, one very lucky male) appears to be permanantly pregnant, excluding the male of course, who is permanantly happy. I've noticed a "gravid spot" on all of them. They have remained this way since they were purchased, 3 months ago. 

How is this possible?
I obviously must have faulty information since gestation for small fish cant possibly exceed 3 months. One sad batch of babies was found soon after their introduction but *only three survived *due to my obliviousness of them. 

Side Question.
My 3 little fish fry are in a 2.5 gallon hex aquarium that I aquired from a sketchy friend. It has some sketchy gravel in it and smelled kindof... sketchy. I cleaned it pretty decently (_with just water_!) and the fish are swimmin away in there with a small sponge filter and no heater. Are they gonna be okay? 

They're munchin on finely crushed flakes and they're not dead yet so I assume that's an alright food for them.

Side note. I realise this thread sucks without pictures. My camera is broken and I am poor. 

Goodbye Blue Monday.


----------



## chris oe

gravid spot only indicates gender, not actual pregnancy. Actual pregnancy usually makes the female look kind of squared off, as will the impending birth. If a female suddenly thins out she may have given birth over night. Fry can and will be eaten by tank mates, births are often unobserved and finished off before the lights go on in the morning. If you want to actually see and raise your fry you may want to have a separate "drop tank" for the female to go into as it approaches its due date.


----------



## Amie

Gravid spot does NOT indicate sex of the fish. My MALE Mickey Mouse Platy has one. Gravid spots also DO NOT indicate pregnancy either. My female Micky Mouse Platy has one too. 

Here`s how it goes for live bearers like Platys: When pregnant they usually give birth after about a month. If they don`t like the water or feel threatened they can hold the fry in longer. some would even say that they can hold them in for up to 60 days sometimes. They can also miscarry or abort them sometimes too. Here is the kicker though-they can hold sperm for 6 months to a year after mating with a male. So, potentially, a female Platy can mate once and drop fry about once a month for about a year before needing another male. I have also heard though that they will take fresh sperm if it is around instead of using their stored stuff. But for that to happen the female would have to mate with the male less then 48 hours after giving birth. 

Ignore the gravid spot when trying to figure out if a female is pregnant and simply concentrate on the size of the abdomen. When they are ready to give birth the belly will be ÒMG-she-is-going-to-split big. It might take a little time to get used to if you don`t have much experience with Platys but as you get to know them more you will quickly learn the look of a Platy after giving birth and one that is about to.

Sexing of live bearers is done by looking at the fin on the bottom of their bodies next to their anal vent. If your not sure you can upload pics and I can tell you or I can get pics to illustrate. 

So the 3 fry have been in the other tank for about 2 months or so....is that right. They should be okay. Usually if your going to lose fry they will drop off within the first month. The flakes are fine for their food. Although I`m sure they would appreciate some variety like freeze dried brine shrimp or something. Not sure how it`s going to be for room once they get a little bigger though. Also, you want to be very careful with that tank, the smaller the tank the quicker water parameters can get fooled up and hurt and kill the fish.


----------



## chris oe

yes gonopodium (modified fin you are referring to) is the best most reliable way to tell gender, but no, males can't have a true gravid spot. Best they can have is a misplaced pigment spot that looks like a gravid spot. That will happen sometimes, so yes, you can have a male that looks like a female, but you won't open one up and find eggs in there unless there's something really weird going on. That's what the gravid spot is, is just the egg area showing through, but my point was, they'll show through whether or not the eggs are fertilized.


----------



## Amie

Are you sure. I always thought the gravid spot was suppose to be the eyes of the fry. Eggs not fertilized-no eyes.


----------



## chris oe

Yes, I'm sure. The gravid spot gets more visible/darker as the fry get bigger/older and very close to delivery in very light colored guppies you can sometimes even see the eyes, but the eggs themselves have color, and show through the skin and that is what the gravid spot is, is just eggs. That's why sometimes females with gravid spots don't give birth - because they just have visible eggs, they just don't have fertilized eggs. But males can't have a true gravid spot, because males don't have eggs. But they can have spots of pigment that look like a gravid spot. Really size and shape is the only way to indicate pregnancy in livebearers.


----------



## jrman83

For males, it's just guts. It is an internal color that is in the same general location as the gravid spot on a female.


----------



## chris oe

jrman83 said:


> For males, it's just guts. It is an internal color that is in the same general location as the gravid spot on a female.


You're funny JR


----------



## jrman83

Well..... Two of the male Platies I have, ones with a color not too dark (Marigolds), look like they could have a gravid spot, but.....


----------



## chris oe

what we're talking about is, there's that silvery envelope that encloses the guts of most livebearers, and in females there's an opening in the back of that silvery envelope, which you can see if there isn't too opaque a layer of pigment in the way, and that opening shows a mass that gets larger and smaller depending on the stage of development of the eggs/embryos in the egg chamber. Males have an uninterrupted silvery envelope and a gonopodium. If you have a fish with both a clearly defined opening at the back of that silvery lining and a completely developed gonopodium, I would love to see a picture that shows that. Live bearers sometimes do change gender when environmental factors are right, or the population is too far skewed to one gender or the other, but I have never actually seen it, only heard people talk about it. I have seen far too many silvery complete gut envelopes (not sure of the correct clinical term) and gonopodiums paired together to believe that your gravid spot is normal, if in fact it is a real gravid spot. Seems more likely to be a patch of pigment, but if it is a real gravid spot, you've got a she-male.


----------



## Amie

But that's splitting hairs. Someone new to the hobby (or addiction HEHE) is not going to be figuring out if the spot is a gravid spot or if it is skin pigmentation. To them if it's in the right spot then it's a gravid spot. I just distinguish with 'true' gravid spot and 'fake' gravid spot. I haven't heard of live bearers switching sex. How hard would I have to work to get them to do that I wonder......... Closely I came was my missexed swordtail. He had a really small gonopodium so I thought she was just keeping her fin closed and had no tail. She is developing one now and has become the gono envy of all the boys (coincidentally, he is also the only one in the tank that I have actually seen move it so I'm thinking the rest might be impotent-from now on I catch my own males at the pet store).


----------



## jrman83

LOL, size matters I guess.....is that what you're saying Amie?

Interesting data on the internals.....I've never seen the inside of a livebearer.


----------



## chris oe

Some varieties are more transparent than others, so they give you a view of the silvery area I'm talking about. Others have an irridescent or opaque layer, and are harder to examine while still alive. Probably dissected only 4 or 5 livebearers, usually because of untimely deaths I was either trying to solve, or seeing if I could salvage the fry (you can't, really, if the fry is anywhere near close enough a stressed/dying female will dump her fry, and immature livebearer fry will not mature without the hormones and nutrients inside the mother. Oh well) but I've probably dissected a total of about 25 other fish of varying types and sizes, pretty well acquainted with the internal organs of the standard fish plan. 

That aside, you're right, the gravid spot is seldom useful for purchasing a pair with the genders you want. If you're choosing among the adults, the gonopodium will be there. The best use of gravid spots (for me) is in immature fish, it is the first gender specific characteristic to appear (before the gono) in guppies, and gives me a few weeks to split the girls from the boys before impregnation can happen. Because pigment (generally) develops later as well, it can be a good first step. But watching for the gonopodium development is the last word. I have been taken in by males with an early black pigment spot in the right area - such things would be rare, except that males with this trait have an excellent chance of reproducing in the grow out tank. (sigh) so I generally have to split gravid from non gravid spot, then keep checking in the spotted tank for gonopodiums, and keep watching in the sorting tank for gonopodiums and shift developing males into a males only grow out tank, and you see late developing males and females (often the best fish because they put more energy into growing than into sexual development) so I have spent many hours examining the sides of tiny, tiny fish trying to determine the difference between actual gravid spots and pigment spots when they were smaller than a square millimeter. You get an adult size fish they practically scream at you. But you also get these smooth, fat, big fish that seem like they ought to be females who suddenly turn out to be the biggest, most amazing males at almost the last minute, and the only way to know that those guys don't belong in the girl tank is that even though they don't have a gono yet, is they don't have a gravid spot either, just a silver bullet, no opening in that silvery gut sack. In a fish that's got transparent flesh with no opaque pigment layers, you can tell without opening anything up.


----------



## Amie

Wow....and I thought I spent a lot of time staring at fish LOL!! Makes perfect sense for what your saying. Think I might try the same thing for my growing fry soon. That's a great idea. I think some breeds might be more prone to having pigmentation in that area then others-both of my Mickey Mouse Platys have it-one male and one female.


----------



## chris oe

I'm guessing there's a point in their development when the mickey mouse pigment layer develops (that they're not born with the markings) although I suppose they could be born that way. Before then you would probably have a better shot at seeing more of the developing insides. There are people who say they can see the gravid spot at birth, but they must have amazing eyesight, 'cause I just can't. 

But yeah, if you want to do something with your strains, like maybe sharpen the shape of the mickey mouse pattern, or if you see a neat mutation and want to build on it, it makes a lot of sense to keep the boys and girls separate right from the start, so you can pick breeding pairs according to what you want to bring out. 

I always wonder about the gender switching thing, 'cause I've read about it in the literature, but with all the effort I put into single sex tanks, you'd think I'd have seen one, but I really haven't, not ever. I don't know if it takes more than just a lack of males among the females, like maybe a particular ph or temp, or if maybe there's a population pressure element to it, like it only happens in really low populations, but I have never ever seen it.


----------



## jrman83

I've seen it on my Sunburst MM Platies before...they have the same lighter outside color as the Marigolds I mentioned earlier.


----------



## Utter Nutter

Amie said:


> I haven't heard of live bearers switching sex. How hard would I have to work to get them to do that I wonder..........


On that subject, I came across this, where several people were claiming that their fish were changing sex. Changing sex link 
:fish10:

Was just reading through this as I was given 11 Platy fry about 3 months ago, I didn't think they would be able to get pregnant until they reached adult age but looking at them now, Im guessing I was wrong. Ive just tried to sex them to separate them (yes bit late now I know, but hey) but cant seem to find any males. I shall have another look when my eyes have adjusted back to normal. Some of them keep getting in parts of the tank where its not so easy to tell.
Anyway, is it going to be dangerous for these frys to be giving birth?


----------



## majerah1

Im not experienced in raising livebearer fry,but on bettas,we raise them in a barebottomed tank.Makes cleaning easier,as you will just siphon the bottom of the tank,and with gravel,its more difficult.To get the best possible growth though you should be feeding three to four times a day.Babies eat tons.Waterchanges are critical as well, as they cant grow right if the waters dirty.In a tank your size,you should be doing about 50% every other day,if you are feeding right.Stunted babies will grow with bent spines,or other defects,so be sure to feed them well.


----------



## bruceaction

Thanks guy.s for such interesting insight into fish details,,re pregnceys..and fry development.


----------

