Differences Between Swordtails And Mollies?

Discussion in 'Swordtails' started by Call Me Mags, Apr 28, 2019.

  1. Call Me Mags

    Call Me MagsNew MemberMember

    (first off, if this isn't the appropriate place to post this thread, do tell me so I can repost somewhere else!)

    So I just found out that my fish, who I thought was a shortfin molly female, is actually a swordtail female! The place I got her at mislabeled her, and I found this out by seeing males that looked exactly like her in other stores (which I was especially excited about because I have never seen a molly with her color pattern and was worried I would never see one like her again, but now I know where to find a whole tankful!)

    Here's a picture of her:
    I had always wondered why the coloring on her tailfin was heavier toward the bottom! And now that I've looked up swordtail color patterns, it seems pretty obvious

    I had done a bunch of research on keeping mollies, and I know they're closely related (along with guppies and platies), but now I'm wondering: what are some differences between mollies and swordtails? Their care? Their behavior? Their physicality? Maybe it'll explain some things I wasn't expecting when I thought I had a molly (like why she's so small when full grown, why she's so aggressive, or why her pregnancies took so long)

    I can't imagine they're very different, but I'd like to ask those who have kept swordtails, just in case there's something major I should or shouldn't be doing. I'm also quite interested in more subtle differences that make mollies and swordtails distinct (besides the males). However, all the threads I've seen so far are more about how they're generally alike

    As for her current care, I have her at molly parameters (75 F, ph a little above neutral, a little bit of salt in the water I know mollies don't necessarily need that to live), should I change anything about that? especially the salt? Currently, she's the only fish in a 10 gallon tank, and unless it's necessary, I don't plan on getting any more until I get something bigger (because of aforementioned aggressiveness)
    Also, do you see any major health issues I could be missing? Is she too thin, do her scales look okay?

    TL;DR: Thought I had a molly, but turns out she's a swordtail! What's the difference? (does she look healthy?)

    Any and all input is appreciated, thank you very much!!
  2. david1978

    david1978Fishlore LegendMember

    I never noticed much difference between mollies and swordtails. Size is about the only thing.
  3. Fiscian

    FiscianNew MemberMember

    Mollies and swordtails are related, share a common ancestor. Most of both are farm raised and don't look the same in the wild, plus, there are many different types of both in the wild.

    Swordtails, most are found in Mexico, or near Mexico, in true freshwater and inland streams, away from the ocean coast, some are found in the high mountains. However, some are found near the coast. Also, swordtails have swords.Usually no salt.
    Genus: Xiphophorus

    Mollies are more widespread, most are found nearer coastal waters and some can tolerate true ocean waters, though most are inland freshwater fish and don't have swords, many have large dorsal fins.
    Genus: Poecilia

    It's a good question that is hard to answer precisely, think of them like 2nd cousins, they can be very similar and very different.

    Your fish is a man-made hybrid not found in the wild and is probably a cross between two species of fish, most swords at fish stores are crosses with platys.

    Note, swords and platys will interbreed, it's argued whether mollies interbreed with swords/platys but some think they can. Mollies are line breed like dogs and cats or with other types of mollies. Yours is likely a platy/sword mix.

    Generally, though not always, especially wild types, mollies are said to be more boisterous. Generally you can treat them as if they are the same.
    Last edited: Jun 7, 2019
  4. coralbandit

    coralbanditFishlore VIPMember

    That is indeed a swordtail .The black in the fins is not the greatest thing .
    There are actually several Universities in the US that use Swordtails to research melanoma .The black in the fin is the beginning of too much black pigment in the swordtail and a precursor down the road in breeding to seeing melanoma possibly ..
    Good black swordtails have clear/yellow fins .
    Fish shape and sharpness of analfin suggest that may be a late booming male ..Ever get any fry from it yet ?
  5. Fiscian

    FiscianNew MemberMember

  6. Coptapia

    CoptapiaWell Known MemberMember

    Female Swordtails can grow to 6”, which is a bigger fish than most mollies. A 10 gallon tank is way too small, and probably the reason it hasn’t grown very big. Swordtails should have at least 40 gallons or so. Other than that I would gradually remove the salt as it isn’t necessary.

  7. coralbandit

    coralbanditFishlore VIPMember

    I have spoken with them in search for fresh White Albino stock ...I believe Ohio also strongly researches melanoma
    Their study says females prefer the deformed males appearance !
    I first came upon melanoma breeding showa swordtails from crossing my colors .Many were well tri colored while others where heavily black finned and had lumps [melanoma] .
    The black swords I had back then [10 years ago maybe] were some of the meanest swords I have ever had .I had one male that if there was less then 10 other males in a 75g with him he would kill them all ! I finally settled on a different black swordtail about 4-5 years ago that I got from 'Lotsoffish' AKA Pete Mang on aqubid and have not looked back since .
    I breed and sell Ed Parker Jet Black swordtails myself .I have had them 4-5 years melanoma free !
  8. Fiscian

    FiscianNew MemberMember

    I'm tankless right now due to a back injury, hit by a tree limb of all things, but hope to join back in next year. Been mostly tankless now almost 2 years, longest I've gone tankless since 1990 or so.

    I recognize that picture, I think, from aquabid. I think I might remember you from aquabid, unless I'm mistaken, seems you use similar photos there. If so, I underbid a few of your auctions, swing and a miss.

    Ole Pete, I've won about 5 of his auctions over the years. I do miss his platy guy.

    I'm planning to focus on endangered species when I return, especially Goodieds/other livebearers/Pupfish but also some of the best lines of domestics as well... and this and that.

    I'm trying to "invent" a method to go pond year round in our milder winters, Deep East Texas. Heat with compost piles using 200 gallon wood tanks!

    Something like this, but built better:

    Parker creates nice lines, they can be pricey, but worth it.

    Do you keep the Alphas?

    I've read melanoma free can be difficult but you must be doing something right to go 4-5 years. If a fish can be sexy, your blacks truly are.

    I took a look at aquabid for the first time in almost 2 years last week, I'm antsy. I'll be keep my eyes open for your stuff.
  9. coralbandit

    coralbanditFishlore VIPMember

    I do have alphas I got from a top notch breeder in Long Island .
    I found them last spring at an auction in Norwalk Connecticut .
    I am just about ready to sell my first of these . I have the super red male and alpha female just about ready to go .
    Honestly chase me down on these fish . I don't auction them but they sell for a good penny and for the most once I list them [like I did just recently] people keep on me for a month or so after . The Jet Blacks I have a problem getting enough males from spawns .For years now ! The white Albinos I have problems getting females from !
    I am with you except the goodieds .Too many people with them just for the $$. My fish earn their $$ and are HARD TO FIND... My sale for the whites says clearly if you can find them anywhere get them ..I have not found them in years ..Texas university says they do not have a enough to sell as their females kill their males ! I am leaning heavily to offering them a batch of males as a donation in the bandits name ..I have like 10 males separated already and a tank full of juvi and fry...They are not easy fish for me to breed either and many consider me the ram guy which again I will say is not an easy fish to breed and raise ...
    Yea same pictures I use on AB..I throw them up here for all to judge first !
    Some one once asked why all my fish are in the same tank ! Glad to see my little method of 'branding' has stuck with some ! The power of advertising ! [ You are getting sleepy! ]
    Last edited: Jun 7, 2019
  10. Fiscian

    FiscianNew MemberMember

    Interesting read. If I run across whites, I'll let you know. I will contact you when my ponds are up and see what's up.

    Yeah, I dislike the greedy types. If I can break even, I'm happy. It's my passion, not my income. A little profit is okay, but too many see $$.

    That's one reason for the bigger ponds, I hope to make them more available and less about $$. Those rare livebearers get insanely expensive and that really hurts conservation efforts, gets me hot under the collar.
  11. emeraldking

    emeraldkingWell Known MemberMember

    Question: What common ancestor do swordtails and mollies have? For that would be a question for me as well. Despite of the fact that I do keep and breed them for over 40 decades, I've never heard about that. So, if that would be true what you're mentioning, I'd be interested in that information.

    You were mentioning that some swordtails are found in the high mountains. But that number is bigger than the word "some" represents.

    About the "mollies", you were mentioning that many have large dorsals. From what we know about mollies in the wild, it's about 50% that show large dorsals when it comes to the males. For there is a serious number of wild strains where males show a short dorsal (no matter the dominance of the male). A lot of smaller wild molly strains won't show large dorsals to be honest.

    There are some wild swordtail strains where males don't have a sword. Or just a tiny sword which is hardly noticable.
    Overhere a Xiphophorus birchmanni (Sheepshead swordtail) which doesn't own a sword.
    ea xipho23 dglz.jpg
    Below: Xiphophorus continens hardly shows a real sword
    Below: And with the Xiphophorus pygmaeus there are males that show a very short translucent sword and there are males that won't show a sword.

    But there are also genuine platies that do show a small bottomsword, like Xiphophorus xiphidium.
    Btw, the spot on his belly is a socalled pseudo gravid spot. Pseudo gravid spots do occur with swordtails and platies. But mainly platies. This has got nothing to do with a female turning into a male. For that's a complete different story. A pseudo gravid spot occurs with certain males when they're juveniles or almost adults. Once it shows, it will never dissappear.

    Mollies and swordtails are two different genera but both belong to the Poeciliidae family. It's not really the genera that makes a natural mating between these two a big problem. It comes to the shape of the genitals. In general with each strain the following is in order: A gonopodium of a male of an ovoviviparous livebearer (males of the viviparous livebearers have an andropodium) differs in shape. The same goes for the female genitals. The gonopodium should be compatible with the female genitals. Otherwise, no actual mating will take place (despite of the fact that a male of another kind has been chasing a female all day). Depending on how close related two different ovoviviparous livebearers are, the genitals "might" be compatible. In such a case a natural mating may take place.
    The black till bluish swordtails as shown in the picture of the topic is a german breed. It's officially named after the german town of Hamburg in Germany. They come in translucent clear, yellow, orange and red fins.

    Overhere some pics of some whites I used to breed overhere.
    Below: White fry.
    Below: White juvenile