I have three fantails in a 40 gallon...I've had these fish for about a year, and only one has ever had prominent white tubercles, but I'm not so sure about the other two. Both have one or two white dots that COULD be male tubercles, but it's never been as obvious as the one I'm sure of. Is the female vent always protruding?

The reason for this thread is that I recently did a 20% water change, and two of them (the male and one I'm not sure of) are violently shoving the other one (the one that I suspect could be female) against the walls and bottom rocks, trapping it, and it doesn't particularly fight back. I'm not sure what mating behavior is like, so I'm asking if this is it :P If not, then I am at a loss. It's very uncharacteristic of them to attack each other, they're usually very close and seemingly affectionate. Could it be that the one they are attacking is sick? The one they are chasing and and attacking is also much wider as seen from atop...but maybe it's just fat and I'm wishful thinking :P

im not sure if im right but it is common for goldfish to attack weaker sicker fish if this is the case you may need to place the fish in a quarantene tank and see what treatment it needs.

It sounds like mating attempts to me Water changes often trigger a bit of loving as the slight reduction in temperature sets them off When mine are in the mood for love the male swims against the female, nips her bum, shoves her around, sits on her head etc. etc!

It can be exhausting for the female, expecially if she has two of them after her so keep an eye on her and consider removing one of them for a while if it gets too much Keep an eye on her for injuries especially if they are shoving her against stones.

Females usually have an 'outie' vent and males have an 'innie' but it's not always that easy to tell especially if the fish is round bodied. The fact that the suspected female is wider is an indicator that she is indeed a female.

HTH - poor little girl!

The one being pushed around appears to be fine in terms of strength, and is still as physically active as the others, so I'm leaning towards the mating idea, haha. Worst case scenario is that you're right...I hope not! I love my fishies!

I hope you're right, suey2, that's exactly what they're doing to 'her', lol. I have a 10 gallon that I can put one of the chasers in if it gets out of hand...or maybe I should just do that anyway, haha.

Take it as a compliment from them - means they're full of beans, good and healthy and ready for love

As long as the female is bearing up well it shouldn't be a problem. Being the same shape they should be evenly matched in swimming ability. The current love of my male's life is quite cunning about outswimming him and he usually ends up wondering where she's gone! His previous girlfriend was a pearlscale and couldn't out-run him but she did usually manage to outwit him He did run her ragged though

If you feed them bloodworm it might be as well to cut back on it for a while, apparently it can contribute to things.

full of love lol!!!

thats funny lol well it made me chuckle

i know fish in love lol

I have 2 male fantails and the larger one occasionally harasses the smaller one, but thankfully this is rare. I nearly bought a spawning net to protect the smaller one, maybe you could use a spawning net if things get too much!

Or if it all gets too much, a very temporary solution is a sin bin (though depending on how many, and who is doing what, can be a protective enclosure) made by floating a plastic basket with holes in inside the tank. Keep meaning to take a picture of this in action, though I don't have cause to use it ATM.