Curious one asked in PetsFish · 1 decade ago

Why guppies develop tails like swords ?

These were not the cross breeds.

India, Maharashtra.


I had guppies with 1 inch swords on uppermost part of tail.

Also had guppies with 2 swords and 3 swords at the end of tail. But the top sword was always longer.

6 Answers

  • 1 decade ago
    Favorite Answer

    I have seen the swords developing in the wild guppy population long back.

    I think it has to do something with the no. of males in the group and the survival from natural enemies.

    These guppies typically have the blue lines or tinge on the back fin and also near the tail starts. Most of the swords were flowing and with a streak of blue in them. The sword length was about 0.5 to 2.0 cm only and all were straight no curves.

    The breeding population was caught near a nallah coming out from a tile factory (glazed cement tiles).

    I used to keep them in water tanks of 3' x 4' x 5' or in the empty 200 L metal drums and feed them with lot of rice flakes. cockroaches and algae.

    The swords were top, top and middle or bottom only or the top, middle and bottom.

    Never observed the combination of bottom and middle sword.

    Most of the remaining tail end was colourless.

    The number of females was very low. About 20 females per 100 males.

    If you grow fry of 100 then you will get most of them as males only.

    It must have been the additional development to attract the females the swords were developed.

    The progeny also used to develop the swords.

    I am a guppy lover from the age of 8 yrs.

    The pictures shown at the site mentioned in one of the answers are different and all are very much coloured guppies and the swords are curved inwards and not straight.

  • Anonymous
    1 decade ago

    My guess is that these are throwbacks. Many years ago when I started in tropical fish we would breed guppies for upper swords, lower swords, and split tails.

    The current lines of fancy guppies are all, to my knowledge, the result of breeding from these strains for the flowing tails and variety of colors now available. The ones that we have in our tanks today would not have a very good chance of surviving in the wild. The large tails would be a very big handicap in the wild.

    It can happen that these fish, through breeding, will revert to a previous form. It is more likely to happen with crossbreeding of the various fancies but can happen at any time.


  • 4 years ago

    Male swordtails have the swordlike tail, women human beings do no longer. you may tell in the event that they are pregnant if the tummy is swollen and there's a black mark, that's the embryo sac. verify there are vegetation interior the tank the place the female can cover on an analogous time as giving start. or it relatively is advisable to place her in a breeder. it relatively is a small sparkling plastic container that hangs on the interior the tank and you place the female in it in the previous she supplies start. the proper a million/2 is V-formed with a slot on the backside that the babies drop with the aid of whilst they are born. If no longer, the mum will eat them. Your tropical fish save sells toddler fish foodstuff which you would be able to feed the greater youthful until they are super sufficient to eat usual fish foodstuff.

  • 1 decade ago

    None, there is a fish called a Sword Tail and the males of this species are the ones with swords

    Edit: Oh one more thing their are fish with what is called a leir (sp?) tail that kind of does this ) on the end. Its like a concave arc with two points

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  • 1 decade ago

    Hi Their is type of guppy that was developed many years ago called swordtail guppy. the following are websites for swordtail guppies

  • 1 decade ago

    just a genetic mutation... happens alot thats why we have all the different varieties of fish and pets we do today.

    Source(s): 9 years as Shelter manager, wildlife rehaber, raising orphaned animals, investigator for animal abuse\neglect and years of owning,training, breeding many types of Animals
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