Black molly fry 1/27/08
Hi Bob,
I have been looking at you website but I am still having trouble locating an answer to my question. My mollies just had 18 babies the other day. We figured she was pregnant but made no move to take her from the tank with the rest of the fish. We have a 55 gallon tank with 3 black mollies, 3 red wags, 2 sunburst platys, 6 neon tetras, and 5 zebra danios. Now we have just added those babies. My question is is how long does it take for a fry to get about an inch long? Do you have some kind of growth chart for fish? Thank you, Misty
<The speed at which fry grow depends upon how much food they get and what the environmental conditions are like. For best results, they should be kept reasonably warm (25-28C) and given 4-6 meals per day, though those meals shouldn't be so big that water quality suffers. Water changes every few days, not less than every week, are also important because high levels of nitrate inhibit growth rates. Related to this is a key factor with Mollies -- the size of the tank. When kept in cramped, overcrowded conditions Mollies grow slowly. Putting the fry in a breeding trap, for example, is never a very good idea with Mollies. Commercial breeders keep them in pools rather than tanks. Under good conditions, Mollies will be about 3-4 cm long after three months, females typically growing a little faster than the males. Cheers, Neale.>

Formation of Lyretail in Mollies   1/1/08
I have a Lyretail Molly that had fry a couple months ago. She was already pregnant when I purchased her so I have no idea who the father was. I'm wondering how old the fry are when they develop the Lyretail?
Thanks,
Deb
<Hi Deb. If the father wasn't a Lyretail, then the fry might not be lyretails either. Aquarists wanting to breed a specific variety of Molly, or indeed any other fish, MUST always purchase virgin females. While some (the better) retailers will sell these, most do not, and you'll need to get them through online traders, fish clubs, fish auctions, and so on. Once you have some virgin females, you can carefully mate them to the specific male Molly of your choice. So given this, the best thing is to simply sit back and enjoy whatever fry you get. They might not be pure-bred Mollies of any one variety, but I'm sure they'll be lively and fun to watch. Cheers, Neale.>

Mollies... repro., gen.      12/31/07
Thanks for all of the help but I just thought of a couple more questions.
When you buy fish at the pet store some people say that they are most likely pregnant; is that true?
<If males and females were mixed, then yes. The best aquariums stores keep male and female livebearers apart, but unfortunately less sophisticated stores do not.>
Do you happen to have a couple pictures of male and female mollies?
<The top two photos of Mollies on this page are males:
http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm
It is REALLY easy! Seriously, if the anal fins of your fish all look the same, you probably only have one sex. Make sure you are looking at the right fin for a start. It's the unpaired fin on the bottom of the fish, close to the anus. On a female, the fin is obviously triangular, just like the anal fin or any other fish. On a male, the fin is a long, narrow, tube-like structure that is bent up against the body most of the time. When the male attempts to mate, he pulls the anal fin forwards, effectively forming a structure like a mammalian penis.>
I keep on looking at the anal fin and I just can't seem to get it.
<Look closer...>
It all looks the same to me.
<Really...?>
Some people say that all mollies are aggressive, but when I watch my fish only one of them (the long one) is aggressive.
<Male Mollies vary in aggression, but at their worst can be very troublesome.>
What fish are compatible with Dalmatian mollies that I can get at my local pet store?
<Mollies are generally easier kept in salted water at SG 1.003 upwards, so choose things that tolerate salt. Guppies, Orange Chromides, Monos, Scats, Archerfish, Violet gobies, Bumblebee gobies, Colombian shark catfish, and so on would all make superb choices. Mollies also do well in marine aquaria, so that's always an option! Avoid fish intolerant of salt such as Gouramis, barbs and tetras. Cheers, Neale.>

Pregnant Black Molly  11/16/07
I have a black molly who, after reading the many other postings, I'm sure is pregnant. She's VERY round and over the last few days her behavior started changing. She hung out at the top of the tank (20 gallon) and then she chilled at the bottom. My other Molly, a Dalmatian, would hang out with her.
<Hmm... female mollies may well hang out in groups. But male mollies harass female mollies, regardless of them being pregnant. So if that other molly is a male, better believe he's annoying her.>
Now she's doing hand-stands (for lack of a better description) and I don't know if this is normal.
<Most certainly is not!>
She looks very big and the bottom of her belly is showing whiter like the scales are stretching.
<I fear this is not pregnancy, but bloating. Many causes, and in the case of Mollies these tend to be three-fold: wrong water chemistry, high levels of nitrate, and lack of plant matter in the diet.>
She doesn't look like she's "floating belly-up." She looks like she's holding herself down and standing straight up (tail-up) in the corner of the tank. IS she pregnant or is she about to die?
<Suspect the latter.>
I don't know what to do. The rest of the community (the 1 Dalmatian and 6 platys are staying away from her on the other side of the tank...
thank you,
Kelly
<Do read the article about Mollies, here: http://www.wetwebmedia.com/FWSubWebIndex/mollies.htm , and act accordingly. Cheers, Neale.>

Molly Fry -11/14/07
Hello Crew!
After conquering the black moor, I decided to move onto the black molly hybrid. I have a twenty gallon brackish tank with four mollies (three female and one male). The tank is approximately two months old, and has been cycled via help of the common milfoil, java moss, and time. So far, the water tests have been exceptional in general. Here's the problem. Besides the four adult fish, I have 21 brand new molly fry. They are currently one week old and in a well circulated breeding net. What is the right size for the reintroduction of these fish back into the aquarium?
Please let me know my best options, and also please direct me to more information on other fun plants to grow in the tank! (Who knew that live plants added so much?)
Thanks,
Megan
<Hello Megan. Rearing Black Molly fry isn't too difficult, though there are some things to watch. Yes, the parents can eat very small fry. But if you grow the fry on for 3-4 weeks, they should be easily big enough to go back into the tank with their parents. To get good growth, feed the fry often but small amounts. Experts recommend at least 6 meals per day! This obviously means you need to give tiny amounts each time, or water quality will plummet. If you decide to keep the fry in a large breeding trap (certainly do-able, if not as good as a breeding tank) be sure and put some floating plants in the breeding trap. This helps give the fry shade, so they don't overheat. Lots of plants work well in slightly brackish water. Almost anything that does well in hard water can be expected to do well at SG 1.002-1.003. Cryptocoryne wendtii, Anubias nana, Java fern, Vallisneria spiralis, Elodea, and the Indian fern Ceratopteris are all good choices. As you've spotted, plants have a great impact on aquaria, especially breeding traps. They give baby fish a place to hide, helping you rescue them. Plants also get covered in green algae and other microbes, and baby fish love to eat all this stuff. Cheers, Neale>
 

Lyretail Mollie with excessive finnage 10/1/07 Hello, I love your site and return to it daily to learn more and more about my addiction to fishes. <Ah, good> I bought 4 Lyretail Dalmatian Mollies this year and placed them in an established two year old 29 gallon tank. One Molly has fancier bottom fins than the others. In fact I cannot tell if it is male or female. I have attached 2 images and hope you can help me figure this out. The yellow spots on the images are from the cheap dig camera. If these pictures are too blurry I could keep trying for another image. <Is a female, but very interesting that the pelvic fins origins seem so set off... one so anterior than the other> Thank you again for all the information and tips. ~Amber~ <Welcome! Bob Fenner>

Pregnant Molly?  7/21/07
Hello,
<Good Evening!>
I have 3 balloon belly mollies in a 10 gallon tank.
<Brackish setup, I hope?>
I went away for the weekend, and came back, and one of my mollies is extremely fat. I cannot tell if it is pregnant or maybe has a case of dropsy. I have never had a fish either pregnant or with dropsy, so I cannot tell what it is (although I suspect pregnancy).
<Highly likely. Mollies are prolific breeders in almost any condition.>
The other mollies appear to be trying to mate with it (coming at it from behind and pushing it around). Is this normal behavior?
<For breeding, yes. Here is a link to molly breeding FAQs on WWM: http://www.wetwebmedia.com/FWSubWebIndex/mollyreprofaqs.htm. Great picture to help you figure out the gender at the top. The one on the left is the male. Note the gonopodium at the anal fin on the male, and the lack of on the female. If the tummy area of the female begins to darken and/or she is showing no signs of illness (listlessness, lack of appetite, shimmying, clamped fins), my guess is it is a pregnant female. Congratulations! Get a bigger tank.>
Thanks for your help,
<Anytime.>
Becky
<Best of luck, Andrea>

Dalmatian Molly Fry– 09/17/07
Hi! First off, your site is wonderful. Since I bought my Dalmatian mollies, I've spent a lot of time on this. I have a question about my newborn babies (born this morning!). A few of them are swimming around the top of the feeder net, but most of them (20 or so) are sitting on the bottom, though still moving. Is this a bad sign? I do have salt in my tank, and I have fed them all once. My temperature is about 78 F. Thanks!
<Greetings. Yes, it is an odd sign for livebearer fry to sit at the bottom of the tank. Often, but not always, this indicates they are malformed. In particular, that their swim bladders haven't inflated properly. Give it a day or two, but if nothing happens, then painlessly destroy them. Assuming you have them in a tank with only mollies, or their own tank, then raising the salinity will help by increasing the density of the water, so they float better. I recommend a specific gravity of SG 1.003-1.005. Naturally, only ever use marine salt mix, not that pointless "tonic salt" or "aquarium salt" stuff some inexperienced aquarists buy. Only marine salt mix (things like Instant Ocean) contains the carbonate hardness minerals as well as the sodium chloride that mollies like so much. Tonic salt only has sodium chloride, and is really just overpriced cooking salt _sans_ iodine. Livebearer fry need 4-6 meals daily and MUST be provided with shade, such as floating plants, or they tend to become overheated under the lights. Do not confine mollies in a trap for more than 2-3 weeks. They need as much swimming room as possible at this early stage or they never develop properly. The most obvious manifestation of this is poor finnage on the males. As always, you'll get best results rearing them in their own tank. By selling on good quality stock in large numbers, you'll easily offset any minor expense. Hope this helps, Neale>

Balloon Molly Birthing Embryos – 09/08/07
Two days ago I purchased a very pregnant Balloon Molly and this afternoon I noticed her giving birth. There were several live fry resting on the bottom of my tank as though they had just been born. I also noticed that some of my 2 week old guppy fry were feeding on what I thought were the newborn Molly fry, but a closer look revealed them to be eating Molly embryos that were in various stages of development, some even would flop around as they were nipped at! Why did my molly eject these embryos, even though some looked to be very healthy? Is she stressed and ejecting all her contents? The newborn Molly fry are actually quite large, larger than my 2 week old guppy fry, could she have been pregnant with 2 distinct "batches" that were not fertilized at the same time?
thanks, Dean
<Greetings. To answer your last question, yes, mollies can have multiple batches of fry at different states of development. Usually these are from a single mating, but the molly can control the rate at which the embryos develop, so some grow quickly, some more slowly. It's called "superfetation" and is quite common among livebearers. Now, my question for you has to be whether you are keeping these fish in brackish water or fresh. Mollies are simply much easier to keep and breed in brackish water, that is, water that has 3-5 grammes of marine salt mix (not "tonic salt" or "aquarium salt") added per litre. Besides salt, mollies need extremely hard, alkaline water to do well: pH not less than 7.5, and hardness not less than 15 degrees dH. Nitrates need to be practically zero if the mollies are kept in freshwater conditions; in brackish water, they don't care about nitrates nearly so much. It is almost certain in this case that the molly miscarried because of the sudden environmental changes between being moved from the pet store to your home. Being very inbred and mutated to begin with, balloon mollies aren't terribly robust animals and frankly I'd just as soon they vanished from the face of the Earth. But that's not my call. Since you've bought one already, you have to realise that in being bred to be a bloated, ball-shaped thing the internal organs are all messed around with and these balloon mollies need extra special care if they are to do well. In other words, don't take chances with them. Observe the water chemistry comments made earlier, keep them in brackish water, and ensure that they are not kept with anything other than balloon mollies. Even other types of molly are likely to harass them, especially the males. As always, remember that mollies are herbivores, and the diet needs to be 75% plant and algae based. Don't feed them regular tropical fish food. Use Spirulina flake, livebearer flake, Sushi Nori, spinach, etc. Only offer meaty foods like live brine shrimp or frozen bloodworms as a treat once or twice a week. Cheers, Neale>

Fertilizing mollies??  9/7/07
How does the male molly fertilize the females??? I see the male chasing different females but how does the ?sperm? get inside the female? Debbie
<Hello Debbie. Male mollies (and other livebearers) have a modified anal fin called a "gonopodium". This functions a bit like a penis. It forms a tube-like structure through which the sperm is guided into the female's vent. The actual insemination process is very quick, as you've perhaps observed. The male will approach the female, and if she accepts him (by no means a certainty) he will flex the gonopodium to the left or right and push it up to the vent. The sperm goes into the uterus and with luck fertilises the eggs. Cheers, Neale>

Re: Fertilizing mollies?? – 09/08/07
Neale,
Thank You So Much, you are very wise and informed. It's so nice to know these little details of information. Thanks Again, God Bless You. Debbie
<Hello Deb, thanks for the kind words. Please do spend some time learning about livebearing fish. If you think the mating is interesting, wait until you find out about the pregnancy! From fish with placentas just like ours, through to fish where the embryos eat eggs the mother produces specially for them, to fish where the embryos actually eat one another, the diversity of gestation methods is astounding. Aquarists often scoff at livebearers for being "easy" fish for "beginners"; in terms of biology, they are among the most fascinating and specialised of all the fishes on the planet. Best wishes, Neale>

Question about Poecilia sphenops & fry  8/13/07
I have not been able to find and answer using searches online, so a quick question.
<Okay>
I have Poecilia sphenops (aka Mollies)
<One of the species labeled as such>
which are certainly good at breeding.
One female in particular just had a batch of about 25-30 fry which have all survived. She was in a breeder net and evicted to the main tank afterwards.
I am now noticing her gravid spot is extremely dark like she is ready to have more. I understand the typical gestation period for Poecilia sphenops is about 28-40 days.
<Yes>
My question: After birthing some 30 fry three days ago. Is it possible for her to have another small batch of fry so soon just days after the first, or would there have to be another 28+ days of gestation time before it was possible for her to have more?
<Livebearers do/can have punctuated development and release of young at times... particularly if/when the females are moved they may postpone... Bob Fenner>
SK

Pregnant Molly 7/21/07
Hi,
I found your site and hope you can help me. My molly fish is clearly pregnant and for the past few days has been hanging out at the bottom of the tank but swimming around from time to time. Recently she has stopped eating and all day today she has been laying on her side not moving her fins or anything.
She looks dead until I see her breathing. Could something be wrong or is this normal behavior?
Thank you,
Belinda
<Hello Belinda. It is absolutely *not* normal for a pregnant molly to be doing what you are describing. Please check that she is not sick. Many diseases cause fish to swell up with fluids (a condition called "dropsy"). In particular, mollies are sensitive to poor water quality and a lack of plant material in their diet. When keeping mollies, like is 100x easier when they are kept in brackish water. Using marine salt mix (not tonic salt) you raise the salinity, pH, and hardness to the levels mollies prefer. Mollies are also vegetarians, and need a different diet to most tropical fish. Algae and green foods *must* be at the heart of their diet. Livebearer flake is made with greens and works perfectly. Without the extra fibre they become easily constipated and excess protein and fats probably lead to problems with the internal organs (it certainly does with other herbivorous fish) In the meantime, I can't offer anything useful here without some words about the conditions in the tank: how big is the aquarium, what is the pH and hardness, what filter do you use, and how much water do you change per week? Have you tested the ammonia or nitrite levels? Cheers, Neale>

Re: Pregnant Molly - 7/21/07
Thank you for your response. Unfortunately I found her dead this morning. The other Molly fish are active as usual, I have 2 others in a 20 gallon tank. The ph seems ok and I do add aquarium salt. I am going to the pet store today to try and find a better food for them and get another ammonia/nitrate monitor. Thank you so much, she was so beautiful!
Belinda
<Too bad. Please do a nitrite test and a pH test. You want zero nitrite and a pH around 7.5 to 8.0. And please, make 100% sure you don't buy anything called "tonic salt" or "aquarium salt" -- these are a con! They're just cooking salt in a different box, and do nothing to buffer the water or raise the pH/hardness. You want marine salt mix (Instant Ocean, Reef Crystals, or whatever). Of the kind used in marine aquaria. These contain salt PLUS essential minerals that harden the water and raise the pH. Mollies like a salinity around 10% normal seawater. Other livebearers are fine with this, but most other tropical fish aren't wild about it, so check before adding the salty water to the aquarium. Always make the salty (brackish) water in another bucket, and once its done, add that to the aquarium. You want about 3.5 grammes per litre, or SG 1.003 if you have a hydrometer. Measuring by spoons doesn't work, so ignore anyone who gives you advice in that format -- they don't know what they're talking about. Cheers, Neale.>
 

Molly Fry upside down   7/16/07 Hello, I discovered a molly fry by chance about a month ago, swimming for her life as she was being chased by a dwarf Gourami. So I put her in the maturation tank inside the 25 gallon tank. Then two days later, I found another one hiding under a big rock. So I put him in with the first one. This is my first time having fry in my tank and I had bought a maturation tank months ago just in case I do find a fry with no intention of trying to breed them. So I continued observing them and they seem healthy and getting bigger each day. About 2 weeks ago, I noticed that whenever I fed them, the female fry started to spiral around inside the maturation tank literally for minutes and ever since she was found, she would prefer to feed upside down and would swim upside down half the time and normally other times. The second fry that I discovered is still smaller than the first, but his behaviors are completely normal like you would expect from any molly. Ammonia/nitrite/nitrate are at or close to 0ppm and ph is 7.0 as I have clown loaches and guppies among other fish in the tank. I also add 4-5 tbsp of aquarium salt each week when I clean the tank just in case there are ick cysts. Temperature is at 78 deg F. Can you please help me? I'd really like to know if this sounds like normal behaviour or if there's something wrong with her, and if so, is there a way to fix it. Thank you very much :) p.s. I have also attached a picture of my tank and the fry. Mandy <Mandy, hello there. When baby fish can't swim properly, it's usually congenital and untreatable. The best thing is to painlessly destroy the deformed fry. Now, some other questions. Why are you adding salt? Your fish don't need it and most of them are harmed by it. "Just in case" treatment doesn't work and if you think about it, it's a pretty silly idea. You either have Ick or you don't. If you have it, treat the tank, and the Ick is gone. It won't steal back in during the night and infect your fish; it only gets back into the aquarium when you introduce unquarantined fish. Mollies need brackish water conditions to stay healthy. Brackish water isn't "spoons of salt" but water made with *marine salt mix* that alters not just salinity but also the pH and hardness. Needless to say, most tetras and catfish can't be kept in a brackish water tank. I personally don't consider mollies an option in freshwater aquaria, period. Ammonia and nitrite shouldn't be "close to zero" they should be *exactly zero*. Mollies are exceptionally intolerant of nitrate as well, at least when kept in freshwater aquarium (they're indifferent to nitrate in brackish/marine aquaria because NaCl detoxifies nitrate). In the meantime, if you fancy rearing and breeding livebearers, check out some of the articles here or read a livebearer book. It isn't as easy as people think, but it is very rewarding, and worth doing properly. Good luck, Neale>

Pregnant Balloon Molly's n Overcrowding   7/16/07
Hi again,
Thanks so much for all your advice you've given me in the past, it's been invaluable!
Your website is a vault of information for me whenever I have fishy questions, of which I have 1 now and I couldn't find an absolute answer to my questions ;-)
<Hello and thanks for the kind words.>
So here it is, I have a balloon molly who is heavily pregnant. I've had her for just over 2 weeks now and she was quite heavily pregnant when I bought her or at least that's what the pet store told me! Anyway, I decided to put her into a fish hatchery in my tank so the fry will survive n mom doesn't get stressed. Mom is doing fine in the fish hatchery but how long do I need to leave her in there? I get the feeling she's missing her friends and would like to get back to being carefree and swimming all over!
<If a female molly has ever been with a male, chances are she's pregnant! Do not keep her in the hatchery. Those things are *lethal* for mollies. Mollies get stressed by them, and often miscarry their broods. You *may* get lucky, but really those things should be outlawed as far as swordtails, mollies, and halfbeaks go. Smaller livebearers like guppies, perhaps viable, but otherwise avoid. The way to breed mollies is to place the female in a rearing tank thickly planted with floating plants of your choice. The cheap kinds like Elodea and Ceratophyllum you can pick up for goldfish ponds work fine, but otherwise cuttings from your aquarium can be used too. The baby mollies will swim into the plants and avoid predation. Some breeders use tank dividers of a sort to create a "safe zone" where the babies are pushed by the water current. Any book on livebearers will have plenty of ideas along these lines.>
Secondly, I've been reading some stuff on your website n I was told when I purchased the tank that it would take around 70 small fish. It's a 30 gallon tank but I think it may be overcrowded? Here's a list of the fish in the tank, and they all seem very happy and my water tests have been spot on:-
<A 30 gallon tank will not hold 70 fish except in someone's dreams. Even the smallest and least active gobies are a gallon per fish, and most everything else is scaled upwards from that.>
3 balloon molly's
2 Siamese fighters (Bettas) (1 female 1 male)
1 Platy
2 Clown Loaches (very small at the minute, will move to a 55 Gal when they
get bigger)
1 Plec
10 Black Neon Tetras
7 Neon Tetras
5 Glowlight Tetras
1 Unknown (VERY tiny fish, but it appears to be either a shark or an algae
eater)
<Well, can't comment on the unknown fish, though I would put money on it being the very nasty "Chinese algae eater" Gyrinocheilus aymonieri, a 25-cm monster that attacks anything that moves once mature. The Plec and the loaches obviously need much larger quarters.>
Is my tank overcrowded? I know the clown loaches will grow very large but I'm going to buy a 55 Gal tank for them when they grow, as I am intending to purchase another clown loach so they have a happy 3sum ;-)
<Good plan. Basically you're at the limit for a 30 gallon tank, and over time many of those fish will need moving out. So for now, don't add anything new, just let stuff grow, and save up for the 55 gallon tank. Many would argue even a 55 gallon tank is too small for clown loaches and plecs, so be sure and do some reading up on those species and budget/plan accordingly.>
As I said all the fish seem very happy and the water values are fine. All the fish have plenty of space so I wasn't sure if my tank was at maximum occupancy or if there was room for more? 70 small fish seems excessive for a 30 gallon tank and I told the woman in the pet store when she told me the tank could house that many fish. She assured me that the tank could definitely house around 70 small fish??
<Whatever the pet store lady was smoking, please tell her, it's time to share. No way you can get 70 fish in a 30 gallon tank. Well, maybe 70 guppy fry, but that's about it.>
Anyway, thanks for all your advice and keep up the excellent work!!!
Sam x
<Cheers, Neale>

Damnation Molly Mom and Her 4 Mo. Old Babies behavior   7/7/07
Hello! In March I wrote to you about my new molly fry and I must say you were extremely helpful. Thank you Tom for all of your insight!
<<Hello again, Bridgette. Glad I was able to help!>>
I currently have 1 female molly, her 11 4 mo. old babies, and 3 new fry in a 10 gal tank. The female ran the male to his death after she gave birth to the first 11 fry she had.
<<I recall this from our last conversation, Bridgette, though it’s often the other way around. You mentioned she was aggressive, though.>>
I am going to buy a 29 gal tank this weekend. Will I need to run this new tank for a month or so before I separate them?
<<The new tank will definitely have to cycle, of course. There are ways to speed up the process, the fastest being the use/addition of BIO-Spira (a Marineland product) which will accomplish this virtually instantly. Not exactly inexpensive but the benefits are pretty obvious.>>
I was thinking of putting females in one and males in another.
<<A good way of heading off a population explosion! :) >>
I know this little tank is overcrowded and need to do something about it right away!
<<Agreed.>>
Also, I've noticed for the last few days that the male 4 mo olds have been looking like they are almost trying to attach to their mother's anal fin. Are they trying to mate with her?
<<A pretty good bet that there’s interest in this regard.>>
Thanks again, as so many people here say, this site is wonderful!
<<Very nice to hear from you again, Bridgette, and thanks again for the complimentary words. Keep up the good work and continued good luck. Tom>>

Molly babies   7/2/07
I'm sorry to bother you again, but my baby mollies are suddenly dying. I have read that it's quite normal to have less than half of babies survive. I thought I was lucky, because within the first 3 days or so no babies died. I figured if they were going to die, they would die pretty early. So why now, a week later, are my babies suddenly dying? This morning I spotted the fourth one. Also, Before the babies were born I wrapped part of a nylon around the part of the filter that sucks in the water, because in the past I've lost babies in the filter. How long until I can remover the nylon piece? Again, I'm sorry to bother you. Thank you for your time, Rebecca
<Hello Rebecca. Some general advice about rearing mollies first. Like all livebearer babies (and fish babies generally) they need lots of food. Six meals a day is perfectly standard when rearing livebearer fry. Vegetarian flake is the critical stuff for mollies, since they are algae-eaters in the wild. Your aquarium shop will have this. But you have to provide small meals, so the water quality stays good, and you have to do regular water changes. I'd suggest 10-20% daily for the first couple of weeks, then maybe 50% every week after that. Mollies are exceptionally sensitive to nitrate, so water quality needs to be good. Adding marine salt mix helps here, and I'd always recommend rearing mollies in brackish water. Lots of people don't, but on balance, it's just better to keep them in salty water. You don't need a lot of salt -- 6-8 g/l will be fine -- but it *does* make a big difference. Once molly fry and born they should be quite strong swimmers, assuming they have enough to eat, but standard practice with fry generally is to use not an electric filter but a simple air-powered filter instead. I use a cheap plastic box filter (cost $5) and a small air pump (around $10-20). Fill with media from the mature filter, and off you go. Air-powered pumps do an excellent job of filtering the water without stressing small fish. Use this instead of the electric filter you have. One last thing: baby fish need shade. It's often overlooked this, but the lights can cause heat stress since the instinct of baby fish is often to swim at the very surface of the tank. Place some pondweed or plastic plants in the tank so there is some shade at the surface. Duckweed and hornwort are my favourites for this. Done properly, your losses of baby fish should be small. I've reared batches of halfbeak fry (another livebearer) without losing any. If you're losing half the babies, you aren't doing something right. On the plus side, you'll soon get more babies -- so practice makes perfect! Cheers, Neale.>

Re: Molly babies  7/4/07
Thank you for all of your suggestions. At this time, I am unable to attain a "simple air-powered filter" like you suggested. Will the electric filter be harmful to the baby mollies? How long until I can remove the nylon cover I placed on the filter (to prevent the babies from being sucked up)? Oh, and can I feed them powdered algae wafers, as well?
Thanks,
Rebecca
<Hello Rebecca. I can't answer the electric filter question because "it depends". In a big tank a small electric filter could be fine, especially if the molly babies were strong and healthy and had lots of places to hide. I've had livebearer fry appear in tanks with electric filters and swim quite safely up at the top among the floating plants. But in a small tank it is perfectly possible for small fry to get "sucked up"! So this is something you will have to work out yourself. If your electric filter can have it's power turned down a bit, then that's an option. Be careful with nylon covers though, as if they clog, and the water flow stops, the pump will be damaged (broken). All else being equal, livebearer babies become quite strong little swimmers within about a month. Powdered algae wafers should be fine. Obviously watch and see they are eating, but essentially they should be good nutrition. Good luck! Neale>

My molly recently had about 28 babies. – 07/01/07
Some are tan, some are black, and some are grey. I was wondering if the babies will keep their colors or if they will develop more/different colors in the future.
<Often do change...>
If they will develop more color, how long until i see this change?
<Weeks>
Also, the babies tummies are starting to bulge a little bit. I read somewhere that over feeding the babies was alright, as long as you remove the uneaten food. But is over feeding the cause of my babies bulging midsections?
<Often, most likely, yes>
How long until the babies double in size?
<A week or so...>
I have them in a ten gallon tank, with no other fish.
And finally, after the babies grow, what is the maximum number of mollies i can/should keep in a five and ten gallon tank?
<Mmm, with weekly water changes, good overall maintenance, maybe ten or so>
Thank you for your time,
Rebecca
<Welcome! Bob Fenner>

Mollies, and more mollies  5/30/07
Hello from Saint Paul!
<Hello from Berkhamsted!>
I am in love with, and now addicted to, your site. So many of my questions have been answered already!
<Very good!>
This little hobby has exploded, quite literally, in front of my eyes. Ten days ago I set up and prepped my 6-gallon tank, and purchased four pot-belly/balloon mollies with my daughter. The salespeople at the LFS, of course, weren't too forthcoming with info about the rapid growth that was about to happen - 36 hours later, four blossomed to 40+! The fry are thriving in a breeding net, and the four adults are negotiating the space around it.
<I'm glad in so many ways. Breeding fish is one of the very best bits of the fishkeeping hobby. It also sounds as if you're putting the babies in the breeding net, not the mothers. That's the correct thing to do with mollies: molly mothers do not like being inside breeding nets at all. Do bear in mind that not all the baby fish will survive. Even with wild fish a certain proportion will have poor genes; balloon mollies are essentially physically handicapped fish right from the get-go, and inbreeding to form bright colours further restricts the gene pool. So it's more than likely a fair number of fry will be deformed or runts.>
Realizing more space is needed urgently, and after more research about my three perpetually pregnant females and one insatiable male, I purchased and set up another tank (10-gallon). This tank is now ready for inhabitants.
<OK, a 10 gallon is certainly better than a 6 gallon tank, but neither is really adequate for keeping mollies. In the long term, you want a "long" 20 gallon tank, or better.>
I know this could go on exponentially, and am intending on relocating fry to either the LFS or breeders of seahorses and the like. I'd like to keep the fry level to a minimum, however.
<If you don't want the fry, then don't remove them from the tank. Most will get eaten. If you need to destroy offspring, perhaps because they are deformed in some way, you can do this painlessly using clove oil; see here: http://www.wetwebmedia.com/euthanasiafaqs.htm >
My specific questions are these: who should I put where? (Adults in one, fry in another?
<If you want to rear the maximum number of fry, then yes, separate them thus. The keys to growing on fry to maximum size in minimum time is [a] providing lots of small meals (six times per day is about right) rather than just one or two big meals; and [b] doing lots of water changes, because pollutants in the water suppress fish growth. You're looking at something around 2 or 3 50% water changes per week.>
Separate the sexes?
<Long term, yes, this helps, but mollies can produce multiple broods from a single mating by altering the speed at which the embryos develop (a process called superfetation).>
Who gets the two-bedroom and who gets the studio?)
<Well, from the adult molly perspective one tank is bed-sit and under a cardboard box under the bridge. Neither is really adequate in the long term. But a 10 gallon tank is useful for rearing fry.>
Should I consider having only females, or does there need to be a male present to ensure bliss?
<No, females mollies are quite happy kept alone.>
Thanks for your input, o crew of ichthyological wisdom!
- Angie
<Good luck! Cheers, Neale>

Molly... System mis-mix   5/11/07
We recently started a 25 gallon tank with 1 albino catfish, 1 sucker fish, 1 rainbow shark, 1 brown crab, and 6 mollies (2 silver, 2 black, and 2 marble).
<This is rather a random selection of animals. By albino catfish I assume you mean Corydoras paleatus, a small *schooling* catfish that should not be kept singly. Suckerfish may be one of two things (I'm guessing). Either Gyrinocheilus aymonieri, a NASTY, AGGRESSIVE cyprinid that reaches around 25 cm and is totally unsuitable for your aquarium. Or else it's some type of Loricariid catfish such as Pterygoplichthys pardalis, likeable enough animals that get to between 30-50 cm in length depending on the species and again totally unsuitable to your aquarium. Even in tanks twice the size of yours, either of these fishes would feel cramped, and both together in a mere 25 gallons is really pushing your luck. Rainbow sharks become aggressive with age, and all the crabs in the trade appear to be amphibious rather than aquatic and will spend all their time trying to escape. Keeping them permanently submerged is, needless to say, cruel. Most crabs will catch and eat small fish given the chance, so be careful. Finally, mollies do best in brackish water, something that will be fine for the crabs but not the other fish. When kept in freshwater mollies are very prone to diseases of various kinds. Sorry to say, but this aquarium is a disaster waiting to happen.>
There are approximately 12 fry in the tank (less than a week later).  Should we separate the fry from the adults, and how often should we expect to see new fry in the tank?
<Ideally remove the fry to another tank. Failing that, confine the fry to a breeding trap for 2-3 weeks. None of your fish are especially predatory, but at least some of them (including the mollies) are liable to eat tiny fish given the chance. And yes, mollies will produce fry more or less their entire adult lives every 6-8 weeks usually. Depends somewhat on temperature, diet, etc.>
Thanks, Liz
<Cheers, Neale>

how can i stop the mother and father molly from eating their babies because i want to see the babies grow up big and healthy!!!!!   5/10/07
<Trade in your excess exclamation marks for some floating plants such as hornwort. Check for baby fish each day, and then remove them to a breeding tank. A 10 to 20 gallon aquarium will do. Once the babies are a few weeks old they can be returned to the community tank safely. Do not try put the mother in a breeding trap. Cheers, Neale>

Silver balloon Mollies repro.  4/26/07
<<Hi, Christine ( I hope, since you didn’t sign). Tom with you.>>
I have had a 29 gallon tank for 8 months now and have recently added a male and female balloon molly to the group (2 Bala sharks, 5 zebra danios, 2 swordtails).  
<<Off the subject here but you need to know the Sharks are going to (hopefully) become huge, fast and skittish. Wonderful fish but I, personally, would be looking at a 90 gallon tank for two of these. (Like you really wanted to hear this, right?)>>
We have had the mollies for about two weeks now and one has always been slightly larger than the other.  I believe that it is the female.  
<<Very likely.>>
How can I tell if she is going to have babies and if she had them without being in a net would any of the fry survive?  
<<At the back of her belly is what is known as her “gravid” spot. If she’s pregnant, this area will become swollen with the fry. As to the question of “when”, watch her behavior. Frequently, very pregnant “livebearers” will tend to isolate themselves from their tank mates. She might hang out near the heater, if you have one, or some other corner of the tank. In short, she’ll distance herself from the rest of the fish.>>
I have lots of floating plants as well as some in the gravel.
<<Short of isolating the mother and fry, floating plants are their best bet for survival. Any place where they can “hide” will increase their chances.>>
Also, how would I know when to put her in a breeding net.  
<<If she starts to demonstrate the behavior I spoke of earlier, you should think about moving her.>>
I have also read some of the other questions that have been sent in and some of them talk of eggs.  Perhaps a dumb question but do they lay eggs as well?
<<No. Mollies give birth to live babies but don’t lay eggs. The same goes for Platys, Swordtails, Guppies, Halfbeaks, Mosquito Fish, as well as others. Not a dumb question at all, by the way.>>
I would really like to have my kids see some small fry but I don’t even know what they look like.  Can you help me?
<<Silly answer but, when you see them, you’ll know what they look like. Think of tadpoles that look like fish. They’ll develop rather quickly so, if you can keep them alive, they’ll look more like “real” fish soon. Best of luck and best regards. Tom>>

Balloon mollies, fry, general tank size requirements  4/25/07 
Hey there,
<Hi Olie!>
My balloon molly surprised me last night, giving birth to at least 9 fry.
<They do that when they're kept in community tanks:-) Additionally, females can store sperm for up to 6 mos. or so, and can later impregnate themselves even when there aren't boys in the tank...>
I went out later that evening (after school) to buy a breeder trap.
<I'm not a fan of these at all - quarters are way too crowded and cause stress.  Better to set up a separate 5-10 gal. tank, in my opinion. How large is the tank you have?>
When I got back, I put it in the tank and managed to find 5 fry alive. I have a couple of questions:
-How long do you reckon it will be until they are big enough to release (I have a dwarf gourami)
<Depends. If you keep them in the breeding net, they will very soon outgrow it; however, this will be a bit of a catch-22, as it may take up to 6-8 mos. for them to grow large enough to survive a gourami. However, if you move them to a separate tank, they can grow in peace and not be bullied.>
-How often do i need to do water changes
<Fry are more sensitive to poor water quality than their adult parents. However, the standards are the same: ammonia and nitrite need to read zero (on a quality liquid test kit), and nitrates no more than 20 ppm (probably closer to 10 ppm, due to the little ones' sensitivity). Again, how large is your tank? How often do you currently do water changes? If you already do regular water changes, you shouldn't have to alter your schedule too much; perhaps a small increase in frequency to account for the crushed flake food they require (which can quickly pollute the water).>
-Is there any special care/food needed
<My suggestion is Hikari's First Bites - it's basically pulverized flake, with extra nutrition for the wee ones. Many other brands make similar products.>
My tank has 2 Corydoras, 5 neon tetras, 3 guppies, 2 balloon mollies and a dwarf gourami. It is 34 english litres. Is it full?
<According to my calculations (actually, www.onlineconversion.com did the work!), your tank is less than 9 US gallons. I wouldn't describe the tank as full, but rather as woefully overstocked.  Setting aside for the moment the fact that livebearers should ideally be kept in a 3:1 female:male ratio (at a minimum- it just depends on how aggressive the male you have is), the Corys, guppies and mollies you presently have render your tank full. You *may* be able to get away with the neons, too, if you do regular, good-sized water changes and have very good filtration. I'd suggest 33% 2x per week, unless your test kit tells you to do more. Ideally, you should probably find another home for the gourami, as they can be quite territorial. I'm concerned he may try to make lunch of the guppies or neons, depending on his size, temperament.>
I think the gourami probably ate the fry I lost.
<I agree.>
Sorry I'm jumping around a bit.
<It's OK, but next time, please do use proper capitalization, punctuation, etc., and not net speak...I corrected the issues this time for you, but please keep this in mind when writing in.
With regard to your fry, unless you do plan to set up another tank, you absolutely do not have room for them, I suggest letting nature take its course and let the gourami have a healthy snack. When raising fry, you need to keep in mind not only their "cuteness", but where they will be housed once they inevitably grow.  As it is, your tank is overstocked, and adding more messy livebearers will only make matters worse.>
Hope you can help
Olie from the U.K
<Good luck, Olie. Start reading here - very useful info. on all aspects, including proper tank size and setup, cycling, fish environmental requirements, of this wonderful hobby: http://www.wetwebmedia.com/FWSubWebIndex/fwsubwebindex.htm
Take care, Jorie

New Fish Tank, Mollies 4/12/07
Hi there,
<Hello>
Firstly, Your website is very informative and It's the best website I have found for any information needed about fish... Brilliant!! <Thanks>
My boyfriend and I got a fish tank a month ago. We bought  3 female black mollies, one male white molly and one female white molly with the tank and we bought a Siamese fighter last week.  <Too much too fast, and a Betta/Siamese fighter probably will have trouble in that tank.>   The male molly died within a few days of having the tank... <Check your water quality, my guess is that this did him in.>
My boyfriend spotted a tiny baby fish a couple of days ago but it got eaten in a matter of seconds.. When we got back from work today we spotted another tiny fish and managed to catch it. <More will follow, mollies put rabbits to shame.>  We were so unprepared for the fry so we put him in a plastic food bag...<Won't last long in this, needs good water quality and filtration.>
The white molly ballooned up 3 days ago but lost the weight the next day. <Gave birth.>
Today we have noticed one of the black mollies has also ballooned up... <Expect to see this often, female mollies are pretty much always pregnant.>
All of the fish are now fighting.  <How big is the tank?  Some mollies can be quite aggressive to their tankmates.>
We are very confused why we have a fry as our only male molly died. Any help you could give me would be brilliant..
I really look forward to hearing from you.
Best Regards,
Anna S.
<Female mollies have the ability to store sperm for up to 6 months, so expect more fry.  And as an added bonus in 6 months the juveniles will become sexually mature and start impregnating the first generation and their siblings, leaving you with a tank full of fish.>
<Chris>

Re: New Fish Tank, Molly Fry 4/13/07
Dear Chris,
<Hello>
Thanks ever so much for this information, you have settled my mind!  We have saved one of the fry... :-) <Good>
Have a brilliant day.
Best Regards,
Anna.
<Just a word of warning, plan now for what you want to do with the nearly endless supply of fry that will probably be coming.  Best not to get stuck with a bunch of fish you cannot afford to keep and are difficult to even give away.>
<Chris>

Pregnant molly/barb fry   4/3/07
Hi. First off, I want to say that I love this site. Every time I have a question or I'm bored and want to look up things on my fish, I come right here.
Anyway, I have a small issue that I don't know how to address. I have a 10g tank with 4 cherry barbs (1 male, 3 females) and 4 mollies (1 male and 3 females). I  just recently got 2 sailfin mollies
<Mmm, these do get very large...>
thinking it would balance out the ratio, before it was 1 male and 1 female, but the male is still constantly harassing the one female molly that is pregnant.
<And there's not enough room here for her to "get away"...>
He doesn't even go near the other 2. I found 1 cherry barb fry the other day
<! Really? This is much more likely a Molly>
and put it in a one gallon I have until it gets big enough that it won't get eaten in the 10g. I want to separate the 2 mollies because she is pregnant. My problem is this. I don't have another tank so that I can separate the male and female molly except the one gallon that the barb fry is in. Would it be ok for me to put one of the mollies in there at least until the molly gives birth?
<Mmm, not really... trouble with waste processing mostly...>
And also, which do I put into the tank? I don't know if either would eat the cherry barb fry but I desperately feel the 2 mollies need to be separated until she gives birth. I think she is very stressed out by the male molly. Thanks in advance.
Laura.
<Let's see... if it were me, I'd return the Sailfin Mollies... you don't have enough room for these... Perhaps trading these in for the equivalent money for a "breeding trap"... a simple "net" type one will/would do here, to hang in the ten... perhaps to give the male a "time out", place the females when they are close to giving birth. Bob Fenner>

Balloon Mollies 3/28/07
Hey guys!
<Hello>
I was just recently given 2 balloon mollies as gift. The person who gave them to me told me that the fish store told her that one of the two was male and one was a pregnant female. The only problem is I can’t tell which is which! They’re both huge! The only fish I've had any real experience with before are guppies (which I'm glad to say are all adjusting very well to their new additions), so I'm really in the dark here. <Really not so different from guppies, both like salt in their water, live-bearers.> I tried looking for a black spot on each of the mollies' bellies but one is completely black and the other is gold with black spots so I cant tell. The only other clue I have is that the black molly chases the gold one around a good portion on the time. Is this a good indication that he is the male? <Sort of, but have seen many aggressive females who chase everyone.> In any case, I know I have to go out and get a few more female regardless of who’s who, correct?
<Would be best for the female, ideally a 4-1 ratio females to males if the tank is large enough.>
Thanks for the help!
-Jess
<Sexing mollies is quite easy actually.  Females have large fan shaped anal fins, while males have tube shaped anal fins (gonopodium).  Please see here for more http://www.wetwebmedia.com/FWSubWebIndex/mollyreprofaqs.htm .>
<Chris>

Re: Pregnant molly   3/21/07
Hi there,
<<Well, ”Hi” back, Bridgette.>>
Thanks Tom for responding to my question yesterday about my aggressive female Dalmatian molly who just became a new mother.
<<Happy to do so, Bridgette.>>
When I woke on Saturday morning, the male molly had passed away…I’m afraid she may have run the poor little guy to death. He was such a passive fish. Very sad. L
<<I’m sorry to hear this, Bridgette.>>
All the fry seem to be doing well.
<<Excellent!>>
I bought some live plants to float at the top of the 10 gallon tank for some added hiding spaces for the little ones.
<<Good.>>
Right now only the fry and the mother are in the tank.
<<Best to keep an eye on “Mom” where the babies are concerned, Bridgette. These fish lose their appetites for a number of hours after giving birth – figure about 12 hours, or so - but aren’t above viewing the fry as a potential meal later on. So much for Motherhood! :) >>
The test strip for nitrite shows somewhere between 1 and 3 (API test strips), I did a partial water change yesterday and again this morning. Should I continue doing these changes every day or more than once a day until it reads zero? I was unsure of how often to do the changes because of the fry.
<<The fry will need the most pristine conditions you can give them. Between one and three ppm is too high even for an adult so you definitely want to stay on top of the changes the way you are. Hard to “over-do” it where little ones are involved.>>
Yesterday the mother was making lots of poop. It seemed like every 30 minutes she was going. Is this normal for a new mother?
<<Considering the relief on her intestines that giving birth provided, I’d say this isn’t at all unusual. As long as the coloration of the feces is normal, I wouldn’t be concerned at all.>>
I put a little piece of nylons over the filter so that the babies wouldn’t get sucked in…is that ok for now?
<<Perfectly fine and a wise move on your part.>>
Also, today the mother has been staying at the bottom of the tank, almost laying on the gravel. She will wiggle for a little while then stop. Could this be a sign of her going into labor again soon?
<<We talked about “recuperation time” during our last “visit” and this is likely part of that. I wouldn’t discount the added possibility, though, of her giving birth to more fry. Livebearers have the habit of spreading this out over two, or three, days on occasion. Not part of a new pregnancy but a continuation of the current one.>>
Thanks so much for all your help. This site is truly wonderful and I appreciate all the help you can give me!
Thanks again,
Bridgette
<<I’m glad to be able to help, Bridgette, and we all thank you for your kind words. Keep an eye on the mom and babies and get back to me if you see anything that appears troubling to you. Best regards. Tom>>

Urgent question... Not so... Molly repro.    3/20/07
Hello Guys, I recently found your site and like mostly every other fish owner have become obsessed.
<I can't leave either!>
I just have a few quick questions. I have a 10gal tank setup with 1 male Dalmatian molly who has somewhat or a larger/longer dorsal fin paired to 3 females (1 white with minimal black spotting, 1 black with a silver flecks on its belly, and one greyish with black spots) Also in the tank inside a breeding chamber I have an orange balloon molly that looked way more plump then the rest at the store and a Dalmatian/black molly who seems a bit more plump then the others)
My first question is exactly how much bigger do they get when you know they are about to have babies, I've done lots of research some say they get huge some say they have appeared normal or even skinny.
<Definitely bigger most of the time... perhaps twice in girth or so...>
I've looked for gravid spots but on the dark ones its nearly impossible and on the white i cant see anything so my bet is she's either not pregnant/in-between or in very early stages. The orange balloon who was more plump then her tank mates at the stores vent areas seems almost lighter not darker so again its hard to tell.
<Agreed>
If any successful breeding happens am assuming the offspring are just going to be a mix bag of colors so to speak sine at the moment am not working towards any color variations.
<Correct>
Its been hard to find any pictures of mollies in any stages of pregnancy and since this is my first time with this particular fish am having trouble picking which females to separate for minimal fry loss.
<Mmm, I'd get on over to the public library. There are plenty of fine works in print that have such info., graphics re the reproduction, keeping of livebearers...>
Any suggestions links or pictures would be a great help I look forward to
hearing from you!! Thanks a lot!
~Peter
<The library... Bob Fenner>

Pregnant molly  3-13-07
what...
<What - proper sentence case is very much appreciated, so I don't have to re-type everything...>
...is the gestation time of a black molly??
<All livebearers generally have a gestation period of 4-6 weeks>
i...
<I>
didn't notice her getting big until being away for a weekend??!!
<Any time mollies, platys, guppies (i.e., livebearers) are kept in a community tank there's a pretty good likelihood that the girls will be pregnant - these fish reproduce almost exponentially, or so it seems.>
Please get back to me ASAP, so I can go out and get a breeder net if needed!!
<Let me ask how large the tank currently is, and what fish are housed in it? If the tank is large enough and has enough cover (plants, decor, etc.) for the birthing mom and her new babies to hide in, it's perfectly OK to allow the female to give birth where she is. I've been keeping mollies for several years now, and have yet to see an adult eat its own young.  If you have bigger fish in the aquarium, that's another story; fry make a tasty treat for lots of fish...
I discourage the use of breeding nets, as they tend to needlessly stress the birthing mom out. If you have the room to raise and care for the babies, best thing to do is put the pregnant girl in her own cycled 5 or 10 gal. tank.  But again, do keep in mind that livebearers are virtually almost always pregnant, and you will soon be overrun with the cute little fry if you don't think about what you plan on doing with them!
Do be sure to keep your water quality pristine, as fry are even more sensitive to poor water quality than their adult counterparts...
Good luck, Jorie>
Thanks!!
Carrie

Pregnant Molly Question   3/4/07
<<Greetings, Vince. Tom here this morning.>>
I have a Dalmatian balloon Molly that has been hugely pregnant since the end of December.  How is it that I have seen no babies yet?  I haven't ever had this happen before.  It's driving me crazy.
<<A plausible, if somewhat obscure, explanation would be that the ‘first’ pregnancy became unviable and she never gave birth. Since sperm can be stored by livebearers such as Mollies for approximately six to eight months following a single mating, it’s possible that your Molly started a ‘second’ pregnancy before the unviable fry had been completely reabsorbed into the mother’s body. I can’t say that it’s not a “stretch”, Vince, but your Molly is far past her gestation period from December and should have gone through a slim-down period of some description whether, or not, she had given birth. Without any other outward signs of ill health or stress, I can’t think of another explanation for her remaining “hugely pregnant” all this time.>>
Info: The tank is healthy, with 3 fry (10 weeks old), one male other than this female.  I used to have another female but she died 2 days ago- no apparent reason.  Live plants and snails.  Nitrates, nitrites, and ammonia always test low.
<<You might try isolating her if possible. The change, and relief from potential stress from the male, might help Nature take its course if she’s near birth, which I would surmise she must be by now.>>
thanks-
Vince
<<You’re welcome, Vince. And, don’t go crazy. That’s my job. Good luck to you. Tom>>

Brown Dalmatian Mollie fry - deformed spines?   2/13/07
Hi Crew!
<Hello there - this is Jorie>
Hope you are well! My question concerns the fact that I have 3 batches of Dalmatian Mollie fry in a large nursery tank. I know who the father is of the two oldest batches (2 at 8 weeks and about 10 at 21 days old) but not the father of the newest batch (about 15 at 17 days old). The second oldest batch of mollies are definitely Dalmatians but are brown and appear to be of a slightly different shape with longer bodies and a tummy that turns in rather than out.
<Hmmm, this could be a curvature of the spine - this condition is usually seen in guppies, and is likely caused by overbreeding, but it can occur in other livebearers as well.  Depending upon the severity of the deformation, the fish could grow up and be just fine, or they could be stunted, have all sorts of health problems, etc.  In all honesty, this is what "culling" is used for...but many times people destroy the affected fry simply because they won't be of "show quality", which shouldn't matter to many of us...>
They are all well and active.
<That's the most important sign.>
Parameters of the tank are fine although I seem to have a bit of rust mould growing in the tank.
<Likely some sort of algae - I've got the same problem in my 10 gal. Figure 8 puffer tank, due to his messy eating habits.  I suspect if you are feeding pulverized flake food, or other traditional "fry food", some of it isn't actually being eaten and is decaying in the tank, causing what you describe.  Simple solution is an algae-scrubbing pad and more water changes...>
My question is that why is that particular batch of mollies brown and of a different shape?
<Likely caused by genetics...>
I've done some research but can't work it out! I do hope you can help!
<It sounds as though all the fry are moving about and eating. I'd suggest keeping a close eye on them, and if you start seeing problems, then you may have to look into euthanasia. But as it sounds, for now, all is well; enjoy your little cuties!>
Best Regards,
Rachel UK
<Good luck, Jorie>

HELP PLEASE! Molly repro.   1/27/07
Hi,
<<Hello, Brittany. Tom here with you.>>
I've been online researching cures for things I've lost a lot of fish from... and I always come to your site for answers.
I have lyretail and sailfin mollies, as well as 3 Corys.
<<Behaviorally compatible species, Brittany, but not ‘environmentally’ compatible. Mollies are widely considered to be a “brackish” water species of fish, i.e. salinity levels between 1.11 and 1.17. Corys are strictly freshwater species as are all ‘scaleless’ fish, Plecostomus varieties included among others.>>
A minute or two ago, I went to check on my fish.  I had put a male and female together in a "net breeder" to later move them to a tank so they could breed.  When I went upstairs, the male and female had been together for 2 hours or so, the male was picking at the female.  At first, I thought she was dead by the way she was floating in the water and the way the male was "lipping" at her.  When I removed the male, I saw her gills were moving, and she was managing to swim.
<<Livebearers such as Mollies almost never require being separated into a breeding tank in order to mate. Chances are close to 100% that she’s already mated with one of the males in the main tank. What we refer to as “breeding” tanks, in this specific instance, would be used for the pregnant females to give birth away from other adults that will see the fry as “food”. Egg-laying fish would, potentially, be a different case all together since the eggs might well be seen as food by the adults making the production of their fry difficult, at best, without separating them from the “herd”.>>
The female is a sunset molly. Very, very bright orange color with beautiful markings.  Now, she has a transparent "patch" on her head, and from the center of her body to her tail, she has lost all her color but a very pale yellow.  Her fins, tail and dorsal look like that of a fish with shredded fins from fin rot, but she was perfectly healthy just hours ago.  I'm assuming the male did something to her, perhaps attacked her... but I don't know what's wrong with her... she's not bloody, just pale and her fins appear "stringy"...
<<For the future, moving a fish is highly stressful. Right up there with being attacked by a predator.  Next, the male will be relentless in pursuing a single female in any system which would only add to her stress.  In a small tank, she’d have nowhere to run or hide. Last, we can’t discount the individuals themselves regarding how easily stressed the female might be and how aggressive the male is. As “innocent” a move as this may have seemed, it was a recipe for problems.>>
She does still swim around, but have limited use of her tail.  Please tell me what to do... She is a very lovely girl and I don't want to lose her as she was very very healthy and a rare find.  I'm sorry for the lack of grammar and what not. I'm in quite a hurry and a nervous wreck.
<<I completely understand, Brittany. Let’s do this. Move the male back into the main tank…now! Leave the female in the small tank and we’ll convert this to a temporary hospital tank. Depending on the size of the smaller tank, I want you to perform a small water change (as you normally would) but add aquarium salt to the fresh water, letting it dissolve completely before adding it to the tank. The ratio of salt to water that I’d like you to shoot for is one generous tablespoon of salt per five gallons of water. (I’d help with the math if I had the specifics from you.) Keeping a close eye on her goes without saying here. If you don’t already have them, I’d consider a small, submersible sponge filter and small, good-quality heater for this tank while she recovers. No need for any but natural lighting during her recuperation.>>
I know you get tons of emails, but please respond ASAP!!!
~Brittany
<<If you’ll keep me posted on how things are going I’d appreciate it, Brittany. Best of luck to you and your Molly! Tom>>

Dalmatian Molly Fry - it's not OK to kill them because you didn't know the habit of livebearers   1/25/07
Hi,  I purchased a Dalmatian molly two weeks ago, it's (not surprisingly) pregnant!
<That's the joy of having livebearers...>
  I don't want the fry, is there any chance that the molly, 2 neon tetras, 2 guppies and 1 bumblebee goby will eat them all?
<I think the tetras are your best bet...I've never personally seen a molly eat its own kind (though I've read about it), and the guppy and bumblebees probably don't have large enough mouths.>
  If not, what is the kindest way to "put them to sleep"?
<Ummmm, I'm sorry, but my opinion is that's not a viable option.  If you really didn't want the responsibility of caring for fry, well, then perhaps you should have done your homework and not purchased a female molly from a community tank.  At this point, see if you can "donate" the fry to a LFS - they'll likely use them for feeders (at least they're dying for a purpose), or perhaps a friend. Please, next time, do your reading prior to purchasing a live being; you are responsible for your fish, as well as any babies they might have, and you have a moral obligation, in my opinion, to do you best to care for them. I cannot knowingly tell you how to kill your fish for no good reason - sorry.
As a side note, bumblebee gobies are brackish water fish and belong in water with a salinity of around 1.005.  Mollies and guppies also thrive in these conditions, but tetras do not. You have two incompatible species together here...>
Cheers,
Joscelyne
<Forgive my terseness, but this just isn't appropriate, in my mind.
Regards,
Jorie>

Pregnant Molly ??   1/12/06
<<Hello, Dianne. Tom with you.>>
I have a balloon belly molly that my husband has been swearing was pregnant. Much to my surprise yesterday morning, I got a glimpse of a fry.  
<<See, sometimes we guys know what we’re talking about. :) >>
Unfortunately we were not prepared for this, and we haven't seen the fry since. I'm sure he was eaten by one of the other fish in the tank.  
<<That’s where my money would be, Dianne.>>
The mother molly is still pretty good size, and my husband thinks she is still pregnant.  We have put her in a breeding net, but I don't want to keep her in there if this isn't possible.  Any insight?
<<Put your money back on your husband, Dianne. The birthing process can actually run out over a couple of days. If memory serves (an “iffy” proposition in my case but, still…) we had a writer, not too long ago, whose Platy had fry over a period of three days. Somewhat unusual, to be sure, but it can happen. Try, if possible to give the mother some isolation afterward. Frequently, the mother doesn’t fare particularly well after giving birth and needs to recover without the “attentions” of males that aren’t noted for being very sensitive to her condition. Let’s call it for what it is. Males in the livebearer group are ‘pigs’. Can’t pour perfume on that one. :) >>
Thanks,
Dianne James
<<You’re welcome, Dianne. Hope all turns out well. Tom>>

Molly Crossbreeds and susceptibility to white spot    1/5/07
Hello from the middle of the UK
<And hello from Chicagoland, Illinois, USA!>
Firstly, your site really is a fantastic resource, many thanks for the hard work you must all put into it.
<On behalf of the WWM Crew, thanks for the kind words.>
I have found different websites have slightly varying opinions on the finer points of keeping tropical fish...
<...there really are lots of views out there.  Of course, there are some concrete basics that cannot/should not be varied, but many things are debatable...lots of differences of opinion, even amongst crew members at times...>
...your site deals with this so well as the answers in the faq's come from different people as do the questions, it's very informative, thanks again.
<Glad you find it useful! I am always looking things up on the site - it's how I've learned much of what I know about the hobby.>
Having prostrated myself at your feet and declared myself "not worthy" :-).....
<Well, you don't have to go that far!! lol...>
I have a 150 gal tank with 2 female Bettas, 1 Plec, 1 Algae eater (long thin light orange sucky fish, not sure what to call it really)...
<another type of Pleco, perhaps? Any pictures for identification?>
...7 tetras of
varying types, 1 Lyre tail molly and 12 fish that came out of the Molly, I think they may be crossed with a Guppy we have in our other tank...
<crossbreeding between livebearers can, and does, indeed happen>
...(we moved her and some of the offspring, she is getting quite big and the kids were taking over the tank).
<Yup, livebearers can/will do that! I'm amazed they haven't taken over the planet with their reproduction rate...>
Water is at 28.3 deg C +/- .2...
<This is the high-side of OK for most tropical fish, but good for the Bettas...>
...ammonia 0, nitrite 0, nitrate around 40ppm...
<MUST reduce the nitrate levels...20 ppm is as high as they should be.>
(most of the time) ph 7.8 constant. Filter is an Atman 882, it's an in tank filter, housing a heater, 2 compartments holding bags of different filter medium and a pump, in that order as the water flows through. I do a 10% water change/clean every week and add a little stress coat type treatment (Nutrafin AquaPlus) each time to the fresh water to remove the chlorine and help the fish, I normally age the new water for 24 hrs before doing the change and add a little AquaPlus (20ml) to the tank.
<Your water change schedule generally sounds OK, but since those nitrates are so high, I would recommend doing a 10% change 2 times per week, until the levels fall under control.  They really are too high and are likely stressing the fish, causing them to be more susceptible to disease.>
The water from my tap is quite high in nitrate (around 40ppm) so 1 of the bags in the filter contains "Nitrate Sponge" to help keep the nitrate at an acceptable level.
<Well, there's the problem, then...if you keep doing water changes with this water, the nitrate levels likely won't drop.  I'd recommend looking into a RO/DI unit, or at the very least, a DI product such as this one: http://www.aquatichouse.com/WaterPurifiers/tapwaterfilter.asp
The RO/DI unit will cost you more, but will save you money in the long run, as the filters don't have to be replaced nearly as frequently as the Aquarium Pharmaceuticals Tap Water Filter product.  I don't know if they'll ship to the UK, but I am a big fan of www.airwaterice.com for RO/DI units.
I'm not familiar with the "nitrate sponge" product you refer to, but it clearly isn't working.  I really suggest a water filtration system.  Everything else you describe seems great.>
Questions:
Can a Molly cross breed with a Guppy?
<Yes.>
The offspring certainly look like that is the case though there was also a male Swordtail in the other tank when she gave birth (She has also had normal Molly babies before and after this
bunch arrived).
<From my understanding, all livebearers are capable of cross-breeding. Might want to consider just housing a single sex, if you want to keep all these different species.>
A quick aside here, she also gave birth to a Platy!
<Without a platy parent?!>
And we don't have any, well we do now!
<OK- I'm confused a little about that one...>
Why are these cross breeds so susceptible to whitespot (The pure Molly is fine as are the rest of the fish)?
<I am by no means a geneticist, but my general understanding is that too much genetic variation causes all sorts of problems, including a weakened immune system.>
If the nitrate level climbs above 50ppm they start breaking out with it,...
<Nitrates really need to be between 0 and 20 ppm...>
...which is fine when I spend a lot of time watching them as I see the first spots and drop in some of the stress coat stuff and check the nitrate levels straight away and the whitespot goes in a
day or 2. HOWEVER, if it's Christmas and I don't pay enough attention, they get in a hell of a mess in a very short time and it's out with the blue stuff (Waterlife Protozin) to fix them.
<Do read here for some helpful information on treating ich.  Keep in mind that the ich parasite goes through various life-stages, and truly the only way to get rid of it is to run the affected tank fallow for at least a month... http://www.wetwebmedia.com/FWSubWebIndex/fwich.htm >
Probably worth mentioning the fish in question are now at least 4 months old, maybe more.>
Any ideas? The best I can come up with is that it's a genetic failing, but I wanted to check it's not something I am doing wrong, I'm not sure they like it!
<It is likely a genetic weakening, and these fish will likely always be more susceptible to disease than their "purebred" parents.  The one thing you can do is to lower your nitrate levels - that's about the only problem I can see.>
Many thanks again
John
<You're welcome. Get rid of those nitrates and you're fish you all likely be more healthy.  Best of luck, Jorie

Re: Molly Crossbreeds and susceptibility to white spot (Now about Nirate levels)  1/5/07
Hi, have replied with the previous message and comments below so you know what's going on.
<OK, sure!>
Firstly thanks for the info, a brief overview of your reply would be that I need to get my nitrate levels down. Great, I have something to do that should fix the problem so...
3 reasons for my reply:
1) Many many thanks to you all
2) Discussing reason 3 may help others with their searches when this message goes into the site
3) I'll be as brief as I can.......
<(1) thank you,(2) this will be posted on our FAQs, and hopefully others can benefit from the info. also, and (3), no worries - I can