Fighting Sailfin Mollies ?

[adi-66]

Hey Guys,

This is my first post...

I have a bit of a problem with my Sailfin mollies.... I had 2 SF mollies (bought as a pair from the same tank at my local aquarium store) in my initial tank set up (Along with 4 Rummy Nosed Tetras, & 2 Red Claw Crabs) unfortunatly one of the Mollies died over Christmas, for no apparent reason... there were no signs of disease or damage to the body, of fins of the poor little chap.

I have let the tank settle back down, and have just purchased a 'replacement' SF molly. I am unsure if it is a male or famale, males have longer/straighter/ more pronounced anal fins dont they ?

THE PROBLEM:

My Original Molly, just hates the new fish and seems to be doing everything it can to get rid of the new fish, behaviour includes :

*Butting into the side of the new fish at speed.
*Attacking it from below, to try and push it out of the water / to the surface.
*Trying to nibble the Anal fins.

Generally being a bully... chasing it around etc... etc...

Does it sound like I have 2 male's and they are just being terrotorial, or is it some sort of a mateing behaviour, and I have a male & a female, who just want to get it on ?

Each Fish is about 80-90mm long (3-1/2 inch) One is Vivid Orange, the Other Silver Grey. I will add pictures later, as i dont have any here at the moment.

Thanks for reading, Looking forward to your answers..

Adi

[wesleydnunder]

Pics will definitely help, when yo can add them. The dorsal fins are usually enough to tell male from female in sailfins. The unmistakeable difference between males and females is the anal fin. In males, the anal fin forms a tube, called a gonopodium.

Mark

[RTR]

What size is the tank? Plants?

[adi-66]

Hey RTR & Wesley.

Tanks is 30 Ltr, its my first tropical tank. I have been advised by my local fish store that the stocking levels are ok. Do they sound correct to you ? I must admit i'm starting to wonder after reading a post on this forum about the size SF Mollies can reach !

As for plants, there are 3 small moss balls, a 10 inch long length of Bog wood, 1 nice big clump od Amazon Swords, I smallish clump of "vallis" (SP?) and some small clumps of "Dwarf Hair Grass ?" dotted around, that as it grown i'm slowley thinning, and re-planting, so hopefuly one day i'll have a nice carpet over some of the bottom of the tank.

Pics will be updated tonight.

Wesley is it possible for you to add images or a more detailed description of a Male & Female Mollys anal & Dorsal fins.

Cheers ,

Adi

[wesleydnunder]

The computer I'm on now is limited so I'll try to get some pics tonight when I get back to my computer.

BTW, welcome to AB!

Mark

[Riverfishgirl]

Mollies don't do too well in pairs since they will pick on each other, whether they're male or female. I wouldn't keep them in less than threes and 30 liters is really small for a group.

As far as identifying male and female, if you look at this picture Image: Poecilia latipinna.jpg - Wikipedia, the free encyclopedia, notice the anal fin is kind of long instead of triangular like in most fish. That indicates a male.

If you look at the anal fin on this fish http://www.flmnh.ufl.edu/fish/Galler...lfinfemale.JPG (not a real good pic but shows the anal fin pretty well) it's more triangular, which indicates a female.

Again, here's another picture which compares side by side http://www.asfb.org.au/research/es/poecilii-4.gif. As you can see the bottom fish has a wide triangular anal fin indicating a female.

I don't think the dorsal fin is a good indicator of male and female in captive bred mollies since it's really variable at this point. My male sailfin doesn't have a very large or rounded dorsal fin.

[RTR]

To me, the tank is too small for sailfin mollies. Mollies are among the more easily stunted fish IME. Part of that may be crowding at the hatchery (sailfin's size is inversely related to the population - the more fish housed together, the smaller the individuals. That holds apparently even in the wild.). Captive bred and maintained sailfins should be bigger if kept in spacious surroundings always. Then they are spectacular fish.

They are not particularly easy-going fish for me, space and plantings really do help. If breeding is the aim, floating plants with dangling roots are plus.

[adi-66]

Just added the images, sorry there not that good, my Digi Camera had flat betteries last night, so had to use the Mobile phones camera.... unfortunatly it doesnt have a shutter speed thats quite fast enough to capture the fish as they swim around.

Looking at Riverfishgirls post i think that they must both be Males. Have a look at the images and see what you think ?

As they probably are both males, am i going to have trouble ? Do i need to split them up ?

Note: They seem to be getting along just fine now, just the occasional knock into each other, always from the older fish in the tank (the orange one) so i guess that he's asserting his dominance ?









Thanks for everyones help
Adi

[Riverfishgirl]

Top one is a male for sure, other one I couldn't see good, but if you think it's a male too it probably is.

[wesleydnunder]

The gold is a male for sure. The other is too, I think, but with the pic quality it's a little hard to tell.

Mark

[Kets]

Sorry, didnt look at the date.