How Do Livebearers Mate

[belmont0182]

Hi all

I have a tank of Mollys and i know that they mate, and i was under the impression that they actually have sex, but my friends at school all make fun if me and say that fish can only lay eggs. thats when i point out that i have "live"bearers, but they still refuse to believe me.:sad

So my question is How do livebearers actually do the deed?

Thanks all!!

 

[mogurnda]

The male's anal fin is modified into an intromittory orgon (i.e., penis) that puts the sperm into the female. So, yes, livebearers "do the deed."

 

[OrionGirl]

The male has a modified fin, called a gonopodium. He inserts this into the females cloaca and deposits a sperm packet. Not quite like mammalian sex, but still sex. The eggs are fertilized internally. The eggs develop and hatch inside the female, and are then born.

 

[belmont0182]

thank you guys, i now have a much better understanding of what happens, this will be very helpful!!!!

 

[tricksterpup]

Belmont:
Everyone has forgotten the most important part of the mating ritual for live bearers, the dance. Now it may depend on what kind of mollies you have, for every live bearer it is different but they still try to sell their best plumage (fins). I have a 55 gallon tank with a mixed of mollies. The males love to shimmy up to the side of the female and flash his Dorsal fin real high. This very noticable with the Sailfin molly. The male will extend the entire fin and flash it at the female. So when you see the male doing a little dance in front of the female, you know some mating will occur. For most live bearers in the family Poeciliidae, they will do a dance which has part of the fins spread out to the max. It is a fun site to watch, especially with my endles.



jim

 

[belmont0182]

I know what you are talking about. My guppytailed Molly does this alot, sometimes i fear that he does it to much and may actually be harassing my females

 

[tricksterpup]

Yes, this can be very harrassing to the female and will stress her out. That is why I keep my Mollies in a 55 gallon with the ratio of 3 to 1. Mollies do prefer larger tanks and with the 1 male to 3 females, he isn't stressing out them out. So if you find your female being very ragged because of the constant mating, i would add a few more females, if you tank can take the fish load.


jim

 

[happychem]

Stressed females, eh? Back when I was stocking my old tank about 6 months ago I had a couple swordtails (one M one F). After popping out 6 youngins (2 were eaten, I think), the original female is still going strong. Sadly, the male died. Fortunately I got a new male in the 4 kids and get to watch "the dance" now that he's old enough.

 

[belmont0182]

so wait, you have a fry mating with his mother? if that is so i thought you wanted to avoid that!

 

[OrionGirl]

Depends on the goal of breeding. While fish inbreeding can result in some deformities, it's not as common as in mammals--fewer nasty recessives. Breeders use line breeding to develop specific strains--color and fin variations, size, temperment, etc. Fish that do not display the desired traits are culled--removed from breeding. If you do not actively remove fry from their parents and siblings, inbreeding will occur.