I have a small group of Sailfin Mollies. Since my large female was close to birth I separated her inside a net breeder. Last night I arrived home from work to find all 8 young dead. I didn't check the net breeder yesterday morning but I checked it the previous nights feeding. Am I doing something wrong or dose anyone have suggestions?

Hmmm, that's odd. What are the water parems like? Are you keeping them in brackish or freshwater?

Hmmm, that's odd. What are the water parems like? Are you keeping them in brackish or freshwater?

Salinity @ 1.010, Nitrate >20 ppm, temp 68-70 deg F.

They reproduce like crazy in a fiberglass tub in back of the biology building at school, maybe you water conditions are too good.

I have a small group of Sailfin Mollies. Since my large female was close to birth I separated her inside a net breeder. Last night I arrived home from work to find all 8 young dead. I didn't check the net breeder yesterday morning but I checked it the previous nights feeding. Am I doing something wrong or dose anyone have suggestions?

With Sailfins never put them in a breeder net and make every effort to never remove the female while gravid from the water. Often times the nets stress the females enough to cause stillbirths and by lifting the fish out of water in advanced stages of development the pressure can actually kill the fry.

are they young still born or egges?
I have reg. cheap black mollies and they will still born about half if they don't get any live foods or greens

I have a small group of Sailfin Mollies. Since my large female was close to birth I separated her inside a net breeder. Last night I arrived home from work to find all 8 young dead. I didn't check the net breeder yesterday morning but I checked it the previous nights feeding. Am I doing something wrong or dose anyone have suggestions?

With Sailfins never put them in a breeder net and make every effort to never remove the female while gravid from the water. Often times the nets stress the females enough to cause stillbirths and by lifting the fish out of water in advanced stages of development the pressure can actually kill the fry.

This is interesting BL. I have raised sailfins both ways, by netting the females into a breeder net and by letting the female have the fry in the tank. I have not had issues with either, other than some of the fry getting eaten in the tank version. What, specifically, about the breeder net do you believe is contributing to the mortality? Stress alone doesn't seem like it could possibly cause a female to have all stillbirths.

I have never seen or heard of this either but it seems like the best explanation so far and it makes sense to me.

I placed the female in the breeder net about a week prior to the what seems to be still birth. These fish eat dry, frozen live and prepared vegetable matter.

Edit: I should add that she seems very small (about 1"). I'm honestly not sure if this is small or not but seems small considering their maximum length.

Maybe the size of the fish has something to do with it. Was it her first batch?

Maybe the size of the fish has something to do with it. Was it her first batch?

Yes

I have a small group of Sailfin Mollies. Since my large female was close to birth I separated her inside a net breeder. Last night I arrived home from work to find all 8 young dead. I didn't check the net breeder yesterday morning but I checked it the previous nights feeding. Am I doing something wrong or dose anyone have suggestions?

With Sailfins never put them in a breeder net and make every effort to never remove the female while gravid from the water. Often times the nets stress the females enough to cause stillbirths and by lifting the fish out of water in advanced stages of development the pressure can actually kill the fry.

This is interesting BL. I have raised sailfins both ways, by netting the females into a breeder net and by letting the female have the fry in the tank. I have not had issues with either, other than some of the fry getting eaten in the tank version. What, specifically, about the breeder net do you believe is contributing to the mortality? Stress alone doesn't seem like it could possibly cause a female to have all stillbirths.

I personally have never had anything BUT issues when it comes to the larger Poecilia and breeder nets. I'm not going to pretend I know why exactly there is a higher level of stillbirths caused by these things but in my own personal experiance I witnessed this over and over again with P. latipinna, P. velifera and P. mexicana when moved to temporary nets or smaller birthing tanks. I've always had better success with leaving the female In situ and removing other fish from the tank containing them rather than trying to remove her.

I should add that she seems very small (about 1"). I'm honestly not sure if this is small or not but seems small considering their maximum length.

This is most definitly a major factor. In the smaller females they will frequently abort fry.

Did you move the female while she was gravid? My experience is only with DAMBUSIA, but when I collect gravid female, and move them to new water, I have had a high rate of stillborns, and weak fry.

try moveing her to an emty tank a week before birth

I'm suprised some of you havn't heard of this, it is very common among mollies especially.. They stress out and have miscarriages for many reasons and breeder nets are one of the most common.. Best thing to do is to put the pair in a birthing tank, remove the male once she's pregnant and allow her to have her brood in peace and have some hiding plants/places for the fry... Of course if you have a large enough tank with enough hiding places, you can just leave them alone and they'll be just fine.. I put a group of about 15 wildcaught sailfins in my mother's goldfish pond outdoors about 3-4 months ago and they have exploded in numbers...

Even in a smaller tank, usually once you get some fry surviving, they begin to ignore them as food.. I've experienced this with most any livebearer as well as lots of other fishes... Kyle

just bought a trio of sailfins, they are definately not wild-type. They are an orangish brown, the male has a huge and beautifully patterned cream-colored sail...anywho both females just popped and I have a handful of albino young, which is pretty neat.

One female and the male to a lesser degree are doing this weird "wobble" with fins depressed. All three are in seperate 10 gals right now. THe "wobble" is performed wiht all fins held tight and the female does it so forcefully that she moves backwards.....what's the deal?

just bought a trio of sailfins, they are definately not wild-type. They are an orangish brown, the male has a huge and beautifully patterned cream-colored sail...anywho both females just popped and I have a handful of albino young, which is pretty neat.

One female and the male to a lesser degree are doing this weird "wobble" with fins depressed. All three are in seperate 10 gals right now. THe "wobble" is performed wiht all fins held tight and the female does it so forcefully that she moves backwards.....what's the deal?

Oh no! The dreaded molly shimmy!
Warm them up fast, it might not be too late. Generally with healthy fish they only shimmy when they get chilled. With pet store mollies, the shimmy sometimes signals the beginning of the end, from ich to countless unspecified ailments they seem prone to.
78 F would not be too warm. Despite being a semi-tropical to temporate species, I find they love heat even more than some true tropicals. If they're only chilled, they should recover soon after being warmed up. Be sure to give them LOTS of greens in their diet. If you have a planted tank prone to algae problems, that's the tank for them. They won't really help your algae problem much but they will greatly benifit themselves. My molly tank is an algae factory, too embarassing to show pics here, but the mollies LOVE it! They graze on algae all day long.
FWIW, after decades of tropical fish keeping and a decade of working in the retail live fish trade, I had developed a strong dislike to the pet store sailfin molly. I used to talk favorite customers out of wasting their money on them. It wasn't until I hand collected my own wild sailfins in FL that I fell in love with them and learned how hardy they can be with good genetics and husbandry.

Oh, I just went back and scrolled through this old thread and thought I'd throw in my $00.02 on the breeder net thing.
Absolutely NEVER move gravid females if you want fry. Floating plants or even floating plastic plants are all you need to get good fry survival. Of course that assumes you don't have other preditors besides the adult mollies.
Try to move them very little for any reason. Keep them in groups, in large tanks, with warm water and be sure they get all the greens possible. Before I mixed other species in, my sailfins only got flake once or twice a week and grazed algae for their primary food. They were always fat and bred like rabbits. Now that I have other species mixed in, they get flake every day and frozen bloodworms 3 or 4 times a week. They eat both with gusto but continue to graze on the algae all day.
Lots of people fail with sailfin mollies. In my opinion, salt is not needed and not the reason people fail. The keys, in order of importance [IMO] are;
#1 Warmth. Mid to high 70s F
#2 Greens in diet. Veggie flakes don't cut it. I don't know that you can even supplement enough in a plantless tank. I've only ever succeeeded long term in planted tanks where they could graze all day.
[Numbers 1 & 2 might be of equal importance, you can't really compromise on either]
#3 Large tank.
#4 Good genetics. Wild is best. For pet shop mollies, look for large size and large, full length dorsals on the males. Crazy colors, small dorsals on full grown males or fancy "lyre" fins and such often mean hybrid with P. sphenops. They just don't seem as robust.
[BTW P sphenops is an awesome, bulletproof fish if you get the small, natural black or mottled grey & black wild types.]

Edited by mikez, 08 March 2008 - 10:43 AM.

the fish room fell to 70 degrees, didn't think it was too cold, usually have the fish room at 75. Trying to equilibirate the humidifier exhaust temps w/ the electric heater...the room got up to 83 a few days ago. Good news is that I have 20 young ~1/3 albino from one of the females. Hope to collect some native strian someday, don't know when I'll be able to though. Ich has started, will treat in a day, when she looks to have stopped having young and I seperate her. The male stopped the wobble....

FWIW Mike, I always had the same general feelings on the sailfins, ever since I was a kid for whatever reason, but I saw these at the LFS, the males were all displaying and the sails were so full and colorful that I couldn't resist. My lone male has no one to display at, may a mirror will let me get a shot... If you have any "extra" wild-type, perhaps some could find their way to Syracuse this summer? Thanks for the input

Edited by scottefontay, 08 March 2008 - 01:42 PM.

tIf you have any "extra" wild-type, perhaps some could find their way to Syracuse this summer? Thanks for the input

Absolutely! Got plenty. I wouldn't ship till temps stay in the 70s. Remind me in a couple months.