Molly Fish - submitted by derail

[derail]

Submitted by - Derail

Common Name of Fish: Poecilia latipinna

Synonyms: Poecilia sphenops, Poecilia Caucana, Poecilia velifera

Common Names: Black Molly, Gold Dust Molly, Dalmatian Molly, Lyre-tail Molly, Sailfin Molly, Short-Fin Molly, Balloon Belly Molly

Category: Live-bearer--latipinna/sphenops (most common specie names)

Genus: Poecilia

Family: Poeciliidae

Origin: Central America, around Mexico and Mexico's Yucatan Peninsula

Main Ecosystem: Estuaries, Rivers, Streams with brackish water and large amounts of vegetation

Salinity: Brackish preferred, can survive in Fresh and Marine

Temperment: Sociable, can be slightly aggressive and will set a pecking order if no other more aggressive fish is around.

Diet: Omnivore, flake food good, but will need some vegetation, esp. algae

Care: Will appreciate having floating plants to hide around (in the case of aggressive ones), and will enjoy browsing on algae. Not difficult to care for

pH: 7.5-8.5

Temperature: 72-80 F, 22-26 C

Hardness: 10-20 dh

Potential size: 4" (sometimes larger)

Water Region: Mainly the top, but will go all over the tank

Activity: Daytime

Lifespan: 3-5 years

Color: Whew...ok. Black, Blue, Gold, Green, Silver, Orange

Mouth: Upturned, no teeth

Tank Size: This really depends on how much effort you're willing to put into it, but given their activity level, I recommend a 15-20 gallon tank for minimum size, and preferably a 30 gallon tank. You will be able to keep around 3-5 molly's in a 20 gallon, and 7-9 in a 30 gallon.

Stocking: When stocking these gorgeous fish, you will want to either follow a ratio or keep all fish of the same sex, but remember that males may not agree with each other. If following the ratio, 1 male to 2-3 females is best, as the Molly's are prolific breeders, just like Guppies. If kept in even ratios, say 4 males and 4 females, the male fish will quarrel amongst each other and also harass the females for breeding to the point of illness and even death. Also, if keeping more than one male, keep odd numbers so there isn't a single dominant male, pair of dominant, etc. You may add these fish depending on your cycling method (be it Fish-In cycle or fishless, or even silent), but prepare to deal with the establishment of a pecking order. By the way, if you do not know, a pecking order is basically which fish eat first. To avoid this and reduce the established territorial issues, you can remove the fish and reorganize the tank so all have an equal chance. This is more important for really territorial fish like cichlids, but I digress.

Sexing: Males are typically smaller than females (unlike Guppies, "colorfulness" doesn't work as both sexes are colorful!) Also, Male Molly's have a tube-like anal fin called the Gonopodium, and females have a "fanned" anal fin. First picture I've added is male, (dalmatian sail-fin), second is female (gold-dust, short finned).

Acclimation: Drip-method is not necessary, as these fish aren't super fragile. Float the bag containing the fish in the water for about 15 min to allow temps to equalize. Then open the bag and add a few scoops of water to the bag. Repeat this after about 10 minutes for 45 min to an hour and then net the fish and add them to avoid introducing any bacteria to the tank.

Breeding: Absolutely simple. In fact, stopping these fish from breeding would be a bigger accomplishment . Keep your parameters around their range, house a male with a few females and it will occur naturally. The male will turn his Gonopodium forward and press it to the female, which allows the transfer of sperm, which she will utilize to fertilize her eggs. Also, note that a female will remain fertile for several months after successfully breeding, even if removed from males since they can store the sperm for future broods. The fry will be born live, hence these fish being called live-bearers, and these fish may drop as many as 10-60 fry in a single brood, with larger numbers being born as the mother has more experience. To assist in encouraging breeding, feed the fish a varied diet of flakes, vegetables (such as unseasoned peas with the shell removed), and live foods or freeze-dried foods (bloodworms are great for this). You'll know when she's pregnant as she will begin to get larger and her belly will ultimately start to take on a "box" or "square" appearance. In the case of lighter colored females, her gravid spot (dark spot by the vent) will grow in size. Gestation for Molly's is about 30 days, give or take a few days depending on diet, genetics, etc.

Rearing the Fry: When the mother is ready to drop her fry, move her to a breeder net to allow the fry to remain safe from the other fish. Molly fish have no maternal instincts, so they will eat their young. In some cases, other fish may even sit right behind them and eat fry as they are born. It is also a good idea to remove the mother to a separate 5-10 gallon tank with plenty of plants and gentle filtration. When the birthing process is complete (which may take a few hours), gently move the mother back to the main tank so she doesn't consume her babies. Babies may be fed liquid fry food, powdered flakes or even powdered blood-worms. When the fry are large enough, they may be moved to the main tank, or let out of the breeder net/trap. Also, if you would prefer to let natural selection take its course, you can let the mother give birth in the main tank, but don't count on all the adult fish to cull the brood and never have babies grow up!

Fry Tank: As mentioned before, the rearing tank should have plenty of plants and gentle filtration. Many people recommend a small internal filter. Floating plants will be highly useful as the fry will naturally hide in these after being born to avoid being eaten. Once the fry have reached an appropriate, they may be moved back to the main tank (whether it be community or specie tank). The appropriate size is a judgement call, typically if the fry are too large to fit in the mouths of the adults, then they will be OK.

Comments: There are plenty of sources that indicate these fish aren't good to be kept with any other fish or as a community fish as they have a somewhat large bioload and can be aggressive to other fish. I've kept Molly's for several years now, recently got into really breeding them and have had no problem keeping them with other live-bearers, such as Guppy's. While these fish can be kept in completely fresh-water aquariums, it is best to have at least 1 tablespoon of aquarium (NOT table) salt per 10 gallons of water (or w/e the measurements on your salt indicate) for optimum health. Being from brackish water, these fish can be kept in this, or if acclimated properly, can be kept in marine aquariums as well, and are fantastic algae eaters, but you can't count on them to remove all the algae! I did have a good two month spat with dealing with a single molly being rather aggressive to the others, since she thought she was the alpha in the aquarium. Adding a male and rearranging everything really helped with it. On a note, as I have mentioned Ballon Belly Molly's. Many people love these fish and they certainly are good a getting attention. Personally, I'm not a huge fan of breeding any fish for a deformity that gives it a disadvantage as far as nature is concerned.
Send me a message if you have any questions or concerns about keeping Molly's, and I'll do my best to get back to ya asap for help

Sources: Kept molly's for years, over 40+ hours of reading up on them online. Some books too.
The Essential Freshwater Aquarium by Betsy Sikora Siino (published by Howell Book House)
Aquarium Fish by Don Harper (published by Collins discover)

Pictures of my own fish . Thanks for this awesome site and the opportunity to share this information! Picture Comments: Pic 1: Dalmation Molly Male, note the lack of a fanned fin on the underside. Pic 2: Female Gold Dust Molly: Note her fanned anal fin. Pic 3: Molly's and Guppy's chilling together, note that these are young fish. Pic 4: A group of two female Molly's and a Male Molly.

 

[Fishie]

Nice profile I love it!

 

[derail]

Nice profile I love it!

Thanks! I was kind of nervous lol

 

[Fishie]

Thanks! I was kind of nervous lol

Lol well you did GREATT!!

 

[derail]

Thanks again. If anyone sees anything I should add let me know

 

[antonis11]

Hi, this is my first post on the forum. In my tank I have 5 Silver Lyre Tail Mollies and I will add more fish gradually. I want to add Glass Catfish but the guy at the pet shop told me that they are incompatible with the mollies. Is it true? Is there any chance they can coexist?

Thank you,
Antonis

 

[derail]

Hi, this is my first post on the forum. In my tank I have 5 Silver Lyre Tail Mollies and I will add more fish gradually. I want to add Glass Catfish but the guy at the pet shop told me that they are incompatible with the mollies. Is it true? Is there any chance they can coexist?

Thank you,
Antonis

From the research I've done, it could potentially be a bad idea to house glass cats and mollies together. I've never kept glass cats so I'm not sure from personal experience, but it seems that glass cats prefer soft, acidic water, where molly's like their water hard and alkaline.
So let me ask this, what size is the tank? This will be most important. Parameters helpful too, especially hardness and ph. Glass cats can be hard to acclimate and sensitive to ich and nitrates.

 

[antonis11]

From the research I've done, it could potentially be a bad idea to house glass cats and mollies together. I've never kept glass cats so I'm not sure from personal experience, but it seems that glass cats prefer soft, acidic water, where molly's like their water hard and alkaline.
So let me ask this, what size is the tank? This will be most important. Parameters helpful too, especially hardness and ph. Glass cats can be hard to acclimate and sensitive to ich and nitrates.

My tank size is 25 g., ph 7.2, GH 16 KH 6

 

[derail]

My tank size is 25 g., ph 7.2, GH 16 KH 6

You've got some pretty hard water, and KH isn't too bad either (KH means carbonate hardness if you didn't know, and measures the water's buffering capacity--that is, the water's ability to resist changes in ph). The ph is pretty good, and a good medium for the majority of fish. I'd say based off your ph you will be able to keep the glass catfish with your Molly's, but I would keep a close eye on them, as Molly's can have a high bioload, which ultimately can increase ammonia, nitrate and nitrite...you know, that whole cycle

I've heard that glass catfish prefer their water softer, less than 10 GH, but fish are adaptable in terms of their environment, so with proper acclimation, I think you might be able to keep them.

 

[antonis11]

You've got some pretty hard water, and KH isn't too bad either (KH means carbonate hardness if you didn't know, and measures the water's buffering capacity--that is, the water's ability to resist changes in ph). The ph is pretty good, and a good medium for the majority of fish. I'd say based off your ph you will be able to keep the glass catfish with your Molly's, but I would keep a close eye on them, as Molly's can have a high bioload, which ultimately can increase ammonia, nitrate and nitrite...you know, that whole cycle

I've heard that glass catfish prefer their water softer, less than 10 GH, but fish are adaptable in terms of their environment, so with proper acclimation, I think you might be able to keep them.

Thank you for your reply derail. Is it possible to make the water softer without using reverse osmosis and at the same time not altering other water parameters?

 

[derail]

Thank you for your reply derail. Is it possible to make the water softer without using reverse osmosis and at the same time not altering other water parameters?

I know two ways other than RO. First is to mix in softer water with your tap, say distilled water or pure rain water (i believe after a while the water is free of chemicals). You could also run your water through peat moss in your filter, but it will brown the water up a bit, which will eventually settle. Future water changes will need to be monitored. But that's normal anyway!

 

[antonis11]

I know two ways other than RO. First is to mix in softer water with your tap, say distilled water or pure rain water (i believe after a while the water is free of chemicals). You could also run your water through peat moss in your filter, but it will brown the water up a bit, which will eventually settle. Future water changes will need to be monitored. But that's normal anyway!

Thank you so much for your help. You have been very helpful.

 

[Fishy Aston]

Well Done!

Lots of information there for anyone who may want to keep mollys.

If there is a thread about mollys care , I shall certainly give them this link!

Well done again and keep it up!

 

[derail]

Well Done!

Lots of information there for anyone who may want to keep mollys.

If there is a thread about mollys care , I shall certainly give them this link!

Well done again and keep it up!

Thanks!

 

[tumblewed]

you have some really nice mollies if u are ever in the CT area im sellin lots of them all diffrent breeds alot cross bred

 

[smomus]

Fantastic write up! I have 2 Mollies (1 Dalmatian, 1 black/Dalmatian) and think they are the most fun, outgoing ones in my tank

 

[derail]

Fantastic write up! I have 2 Mollies (1 Dalmatian, 1 black/Dalmatian) and think they are the most fun, outgoing ones in my tank

Lol yeah they have personality and get really tame. Mine will eat food from my hands and will swim up and nip at me when I'm vacuuming the gravel

 

[Big.Jon]

Lol yeah they have personality and get really tame. Mine will eat food from my hands and will swim up and nip at me when I'm vacuuming the gravel

Great information and well done profile! I love my mollies (6 of them in 55g community), funny you mentioned feeding by hand I let my two and half year old daughter try that out this past weekend they ate it right out of her fingers she thought it was the funnest thing ever.

 

[derail]

Will will be updating a bit soon, adding some more pictures as my babies are growing. Thanks to everyone for your awesome comments!

 

[derail]

Molly Fish-Some additiona pieces of info

In regards to the "Salinity" part of the profile, I would like to add that these fish are capable of living in completely marine environments, and have had reports of saltwater fish keepers housing them in their smaller SW setups so they can help cycle the tank and control algae. Molly fish are capable of taking care of themselves, so other mildly to semi-aggressive fish may be kept with them without too much trouble.

In regards to the "Pecking Order" I mentioned, I have observed over the past year or so that the aggression seems to mainly be on part of female molly's, with male molly's more concerned with food and mating. The part to remember with this is that whenever one states a fish is "Peaceful," "Mildly Aggressive," "Territorial," and so forth, there are exceptions to every rule and this personality observation may not apply to every fish of that specie. I have had Molly's that were so passive, Neon Tetras pushed them around during feeding time, and on the other hand I've had a molly so aggressive that I mused to my wife she'd give my Siamese Fighting Fish a run for his money

In regards to Breeding, I mentioned that keeping them from breeding was a bigger feat than actually getting them to breed. While this remains true, I would like to take a moment and explain some of the color strains (such as Platinum, Harlequin, Marbled, Dalmation, Black, and Gold-dust.) In the wild, Molly's aren't near as brightly colored, but more grey-green with some species displaying certain quirks in color, such as black spots or golden patches. LINE-BREEDING is the operative term here, and is how the beautiful strains exist today. This practice can be controversial to some, and downright acceptable to others. So let's break it down in to a few steps, which will give an idea on how to do it.

1. A pair of Molly fish breed, say a Black Molly and a Gold Dust Molly, producing 20 fry. Of those 20 Fry, 9 have the Gold Dust color, 9 are Black, and two have a mixture of black and gold. (Let's say these happen to be male and female.

2. Now you have the makings of a Harlequin style Molly, and intrigued with it, you decide to separate the boy and girl of this color and breed them again. This results in 25 offspring-15 with the Harlequin style coloration, 5 black, 5 gold. Interested in preserving the Harlequin style, you will ultimately "Cull" the fish that are not of the desired color-You can do this by either giving the unwanted fish to the LFS or feeding the fry to larger fish.

3. So now you take the newest generation of fish and breed a pair of Harlequin Molly's, and get another batch of 25, this time with 20 fish of that variation, 5 of black or gold. Again, you cull the brood to keep that color you desire.

4. We're 2 generations in now (first being the fry from the original parents, second being the children of those fry,) and you've noticed that your broods are more consistent, so you take another pair of Harlequin fry and breed them, acquiring another brood of 25, all of which are Harlequin.

5. Rinse and repeat with following broods, until you get a strain of Harlequin that "Breeds True," always giving you that particular color variation. While this is highly simplified, and will take a bit more line breeding to get a strain developed.

Obviously there are concerns with this sort of breeding over time, because the question of defects comes into play when applying this sort of breeding--you are essentially accelerating Darwin's Law, breeding in the good genes, but inevitably, you may wind up breeding the bad ones as well (say, shorter than normal fins to keep it basic). Ergo, it is a good practice to attempt to introduce a new fish every other generation or so, to help keep the genetic line pure. I won't say whether inbreeding is good or bad, rather I won't divulge my opinion, because ultimately, you will make your own decision about this, and considering all those beautiful, fancy strains of fish we have to choose from nowadays, I'd say Line-Breeding has benefited us as fish keepers, no?

Last thing, kind of a fun Fact I ran across. There is apparently a specie of Molly, Poecilia formosa, that is, for all intents and purposes, all female! These fish have diploid eggs, and reproduce through Gynogenesis, which essentially means they will use the males from another specie, say, P. latipinna or P. mexicana to breed, but retain no traits of the father. From what I've been able to research on them, there are males in this specie of fish, but it is incredibly rare as their genetic makeup is not passed on through reproduction. The Greek's believed there was a race of Warrior Women called the Amazon, turns out it is a specie of Molly fish!

For all of you who've read this, I've posted some new pictures along with this comment as well, and thanks for the positive feedback you've given!
Picture 1 - Harley Quinn (yes named after Batman villain, and also named as a pun to her coloration ), the inspiration I used to break down Line-Breeding
Picture 2 - A Sassy Black Molly, took forever to get that pic. Her mother was a very pale Balloon Belly, thankfully she's not balloon nor pale, also shows Jig the Blue Mickey Mouse Platy and Dumbo the three spot gourami (not being rude, he is just so carefree )
Picture 3 - My Newest Girl, a Dalmation Lyre-tail named Nyx