Beautiful Example of a Rosetail Betta, Photo by John Louie.

The ROSETAIL BETTA is an extreme version of the popular Halfmoon Betta. Rosetail describes a type of tailform. Like the halfmoon, the Rosetail has been bread to have a wide 180° spread of the caudal fin. What sets it apart is the increase in the number of branches in the dorsal, caudal and anal fins giving them a ruffled or feathery appearance. When the fins are spread open the dorsal and caudal fins overlap resembling the petals of a rose. Rosetail bettas were developed as part of the halfmoon tailform in 1989 by breeding team Laurent Chenot and Rajiv Masillamoni. They were not identified with the name “Rosetail” until Jeff Wilson joined the team in 1991. Wilson is also credited with conceiving the term “Halfmoon.” Though Rosetail bettas have been around since the late 80’s/early 90’s they are considered a new variety and have only recently become popular. When they first emerged in halfmoon spawns they were considered an undesirable mutant as they were not producing good quality halfmoons, were unable or unwilling to spawn and were weaker than other halfmoons. While they weren’t used for breeding, they were shown at an IBC convention in the early 90’s and presented under the name blonde-diamond-halfmoon.

The Controversial Rosetail Betta

There has been much debate over the years as to whether or not Rosetail bettas should be used in breeding. Their negative traits seem to outnumber their positive ones. While their extreme branching gives them a unique appearance their heavy fins often hinder their ability to swim well. Their dorsal and ventral fins are often undersized and out of balance, their grow-out rate is slower and they often display asymmetrical body scaling. Breeding Rosetail bettas into a line will result in higher percentage of Rosetails in the following generation so caution should be used when selecting a Rosetail for breeding. The defining traits of Rosetail bettas vary greatly from moderate to extreme. The extreme branching tends to come with more of the complications mentioned above and many breeders opt to cull them. Breeders who do choose to use Rosetails in their line typically choose individuals who show more moderate traits of the mutation.

Choosing a Rosetail Betta?

In addition to the D-shaped caudal fin and extreme branching, the ideal Rosetail betta should have good overall balance in the finnage and should appear proportionate. The scales should be symmetrical and the fish should be able to swim well. Selective breeding should never result in finnage so extreme that it hampers what fish do best… swim.
Steel Blue OHM Rosetail Betta

Rosetail Betta | Photo by Pedro Emidio

  • Parnell-Stark, Victoria. © 2005. The True Story of the Halfmoon. Betty Splendens Retrieved 07-07-11.
  • Van Esch, Joep H. M. “Rosetails.” Flare March/April 2006: Vol 39, No. 5.

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Reader Interactions


  1. Jose says:

    Question I just got one of these.. And I was told by petsmart that it doesn’t need a filter or heater? Also I can’t put the betta with no other fish ( researched betta sites and there r some small fish which r compatible ). Can I get ur input …

    • Christie F. says:

      What Petsmart told you was a very general statement. They did not give you all the information. Yes, your betta may survive in a bowl without a filter or heater but it will be living in a potentially dangerous, high-stress environment. An unfiltered tank is less stable. Fish are more likely to be exposed to toxins like ammonia or nitrite and are more likely to experience drastic fluctuations in temperature and pH because more frequent full water changes are required in an unfiltered tank. Bettas are tropical fish so an unheated tank could also mean they are living in water that is too cold, or worse, water that fluctuates in temperature throughout the day and night. This is a very high stress environment and can lead to more frequent illnesses or premature death. If your betta is in an unfiltered, unheated tank now I would not recommend adding any other fish. Most tropical fish will not survive long in this environment and having them around your betta will only add more stress. There are certainly other fish that bettas are compatible with, but you should set up a proper aquarium with a filter and heater before adding new fish.

      • rohit says:

        Christine , i don’t know about your knowledge in beta fish but to a certain extent i also know Betta fish . they can survive without filtration and without heater if kept in room temperature .i know this because i had Betta in 2011 in a bowl of 1 gallon and without anything except few stones and artificial plant and it was happy that it starts making bubbles after two or three months for mating with female and i know for certain that fishes only mate when condition of tank is good .if you want to know more about fishes then mail me.

        • stephanie k says:

          rohit no they need a filter and a heater b/c the water has to be set for a tropical fish and i know b/c i have had a betta since i was like 5 years and im 19 now so its to stressful for them to not to have the filter and heater just one thing dont leave the betta heater on all the time unplug it for about an half an hour to hour to cool the water thats what i do

        • lol says:

          Oh boy, another one of those people.

        • Edgar Asibal says:

          Heater in a tank is a case to case basis, depending on where you live, the climate, and the room temperature. Remember, betta is a tropical fish. By knowing the extreme temperatures where betta fish can live and adopt it to your situation, then you can be successful in keeping a betta.
          Same with filter, a case to case basis. If planted with live plants, no need with filter. If you want go to the trouble of always changing water periodically, by 3 days or weekly,depending on how big is your bowl/tank, then there’s no need of filter.

    • stephanie k says:

      the one in dover,de told me that they have to have a filter and heater b/c of them being a tropical fish

    • BettaNerd says:

      Jose, I am pretty experienced with bettas and suggest that you do some research about yer little fella. I also highly recommand that you buy a betta from a breeder or petco if you are in USA. pet smart does maintain the bettas in good condition:
      1.cups too small when swimming at least on e part of body touching cup = can result in variouse fin diseases
      2.bettas alrealdy old = will not last as long!

      • BettaNerd says:

        I mean petsmart does not maintain the bettas well!

    • Bette says:

      I had a beta for 5 years and it lived in a small round bowl without a heater or filter.She was so happy I could pet her and she traveled with us for 4 years. I just bought a male crown beta and I have a gallon tank and I am doing the same thing,so far so good.Good luck with what ever you decide to do.

  2. Tara D says:

    Hey Christie,
    I’ve had my betta for about 6 months now. He is just in a little tank but when I bought him a new tank with a filter, it seemed like he went into shock. He refused to eat and stayed as far away from the filter as possible. I got nervous that he would not get better so I put him back in his old tank and returned the other. He has gotten a little better but still isn’t eating near as much as he used to. I want to get him a bigger tank with a filter and a heater but how do I ease him into it so he wont get stressed like he seemed to get this last time? How long would you recommend I wait as well?

    • B says:

      Well, i’m not Christie, but I have been a Betta keeper for about 5 years, So I do have some basic Knowledge. First Off, Bettas’ need a filter that can be adjusted so that they can barly feel the pull. Second, They NEED a heater, as they are tropical fish.

  3. Chance says:

    hey christie umm i have had my fish for almost7 months and i got 2 crown tail bettas and 1 regular betta and 2 female betaas 1 halfmoon and 1 dragon you tell me what i should do i got a tank with only a plant in it and i got them all there own tanks and i was thinkin bout breeding them so could you give me some very good advice and this is my first time and i took into passion with them when my grandma died and betts were her favorite fish so could you call me on 217 848 4275 please and thank you and my names chance

    • BettaNerd says:

      OMG u have alot of bettas

      • Steve says:

        I have 8 bettas! I think I may have a serious problem….

        • krp says:

          i have 16 bettas. 12 in a sorority the others in a divided 20 g.

  4. Alayna says:

    hi Christie i am breeding my apricot male with my blue green female it has been 3 days and still no bubble nest the female is visible and she is round and has vertical stripes and is well “dancing” and so is the male yes there are live plants and i have a heat lamp they both seem very interested they are in a 10 gallon tank it is 78 degrees and the water level is 6 inches i have a Styrofoam cup please help!

  5. Renee says:

    I kept my Betta in a 5 gal tank, with a heater and a filter that has a slow pull.
    I don’t know what happened to, but they helped me through a couple of scary moments with my Betta. I was blessed to have him with me for over four years.
    Please tell me what happened to Thank you

  6. Lee Palmer says:

    Hi there,
    I have always loved Betta Fish. I am looking for a Rose tail or half moon do you have suggestions on where to get a good one for a pet.

    • Wolfman says:

      I would ask the pet store manager if they can get some in I hope you get one.

  7. Ruma says:

    I am surprised by the lack of ethicical considerations when people accept that keeping a betta fish in a bowl, without heating and filter is OK jsu because the place where they bought the fish said so, and they read it on the web. I am a fish hobbiest (betta in particular) and I have a Ph.D in which my research invoved a LOT OF fish husbandry. PLEASE take Christies recommendations about bowl/heat/filter SERIOUSLY. You are not a true fish carer if you do not consider the quaility of life you are giving your fish. Sure they will survive, so would you if you were kept in a room and fed and cleaned.

  8. LM2003 says:

    Cristies right, i am a new betta owner and am new to this but i have done tons of reasearch and take her sereoisly!(sorry about the spelling).i have read most of your site and i have learned a lot!thanks

  9. Bonnie says:

    Oh, for Pete’s sake! I have been keeping Bettas for more than 25 years! Here is the real deal:
    All fish, regardless of species, require a filter. This is non-negotiable. Bettas are not especially strong swimmers, so they do best with a very gentle filter, such as a sponge filter, box filter, or low-flow or adjustable filter. If your filter seems too strong, try baffling it.
    Those little cups they are kept in at pet stores are not indicative of how Bettas should live! They use those because most pet store employees have no idea what fish Bettas are compatible with, therefore would not know which tanks they could be kept in. The tiny cups save space, but are only meant to house the fish until you take them home.
    All tropical fish require heaters. Bettas are high-end tropical, meaning they need water warmer than most tropicals. 78-80 is the perfect range for a Betta’s water temperature.
    They should be housed in no less than a 5 gallon tank. It is all but impossible to cycle, reliably heat, and keep stable parameters in anything smaller. The tank should have a hood. Bettas may not be strong swimmers, but they can jump amazingly well! Don’t give them the opportunity to prove it!
    Yes, many people will say they have kept Bettas “just fine” in a little bowl. Just one question: How long did it live? Bettas are very tough. They can manage to survive in horrid conditions an awfully long time. However, I can guarantee that nobody has kept a happy, healthy Betta in a bowl for 5 or more years. That is the normal life-span for a properly kept Betta. Mine personally average around 6 years. Any questions?

    • Kelc says:

      I’ve had my betta for about 2.5 years. He has been at college with me in my dorm and I’ve kept him in a bowl, no filter, no heater. He also travels to and from school whenever I have a break. He has done just fine. Therefore, it isn’t necessary to have a filter/heater, especially if you don’t have the space/money/resources for it.

      • Julie says:

        Dogs don’t “require” that you take them on walks either. But it certainly makes for better quality of life, doesn’t it?

  10. mr finz says:

    Betta’s are becoming more popular and with that comes more knowledge and research on husbandry. A few years ago salt water reef tanks were considered extremely high maintenance and something that you have tweak and test all day every day but with a bit of research and a lot of trial and error, SW tanks are quite simple. The same goes for betta’s…I have a 4 gal bowl with a cory cat(2 yrs so far) and my crowntail is almost 4 inches not including tail..bit bigger than silver dollar sized with fins flared and he has been kicking for 3 years now and i bought him as full grown adult. I have no filter no heater and all seems to be fine. he is as healthy and unstressed as ever as well as the cory. i also have 2 males in a 15 gal going on 2 years now and no real filter just a small powerhead with a sponge on the inlet to trap trash.
    I’m not saying that your wrong in saying a betta can’t or shouldn’t be kept in anything less than a 10gal fully set up system or that it isn’t beneficial for the fish but people have been keeping betta’s successfully for centuries in a lot less. Regular water changes keep my water good and my betta tends to eat every few days so i feed accordingly, temp stays at about 74-76 night/day…is it easier and less work to set up a full tank system for a betta?..yes. Is it necessary to keep a healthy one?….in my opinion, no I’ve seen wild Betta’s in puddles the size of shoe boxes living just fine so its not a volume issue per say but a water quality issue.
    6yr 90gal semi-aggressive SW reef, 4yr 40 gal invert SW reef, 5yr 40gal FW dwarf cichlid, 115gal FW planted, 3x4gal FW bowls

  11. Elizabeth says:

    Are all betta equally aggressive?

    • BettaNerd says:

      elizebeth: Most bettas turn aggresive when seeing another fish etc. But some have calm temprements, veiltails/bettas are renowned for their differrent characters!

  12. Jrenee says:

    Its a fish that cost me less than $5… 0_o…. i bought a bowl ($1 @ dolleramma) , it died in about a year and a half (this continued a few times). a week ago I bought a new $5 fish, for decor sake i also bought a 1 gallon tank with included water filter (>$20 @ walmart) to tell you the truth i dont care if it dies in a year, or two, or ten… its a fish… you can buy dead fish for food at walmart, its not like a cat or a dog who can look adoringly into your eyes cuddle you and i am not spending $50 on a tank, $25 on a good low pull water filter, and another $20 on water heater… when the fish that will not cuddle me cost $5

    • Melissa says:

      you Jrenee should never be allowed to own an animal. to buy a creature and then just because it wasn’t expensive enough deem it unworthy to have a good quality of life and have its basic life support needs met is just so wrong on so many levels.

    • BettaNerd says:

      There are places to get unexpesive tanks with ok quality, but you should research instead of continuously getting bettas, and end up with deade ones

    • Anna says:

      You should not have fish as pets until you learn to respect life more. Shame on you!

    • Juanc says:

      Wow your the most idiotic people i have ever seen. You shouldn’t be so hateful towards an animal you cannot cuddle with. Yes its a fish but even a fish has feelings. They feel pain amd emotions. They think. They eat and breathe just like us. You dont have to spend money on alot of fish supplies like craigslist will help. And if you dont like the money spending then why even get a fish in the first Place.

  13. bubbles13 says:

    hi! my fish were conditioned and i’m trying to breed them, but when I released the female into the tank, all that the male did was chase her away I noticed that while she was separated physically from the male yet could see him, she was fine, but once the barrier was removed she got really anxious. What happened?!?!

    • BettaNerd says:

      bubbles that was a reallly BAD idea, breeding is not to be done as an experiment or taken lighly, it requires ALOT of time, devotion, money, and care. I understand you are curiouse, but you could end up with more than 300 bettas in one fry to take care of, plus you need to feed them micro- etcetc. I suggest you research. FOR ANYONE ON THIS WEBSITE, DO NOT BREED BETTAS UNLESS YOU ARE A BREEDER OR VERY EXPERIENCED! ( i am not trying to critisize, but you could reallyy hurt your bettas by doing this!)
      smile 🙂

  14. Wolfman says:

    Oh yeah about the stamina I don’t recommend anyone to train their bettas for 7or 8 hours cause it won’t work your betta will only last for a hour and if you get a fighter plakat betta it will only last 5 hours. My baby plakat bettas will be different they will last 7or 8 hours cause they are from Malaysia.

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