Hello everyone! I am new, and really excited about all of the Florida native fish. Eventually, I would like to set up a huge tank with several species.

For now, I have an 18" x 6" x 7" tank, and was wondering if it is possible to keep 3 least killifish in it. It is planted, and cycling.

If it is possible, could I keep three males without aggression issues? I dont really want to deal with babies at this point.

Thank you so much for your help, and for such a great forum.

If by least killifish you mean heterandria formosa, yes, I think you could keep them in there. Without aggression? Well the males nip at other fish but they don't cause damage. They're more nippy than other livebearers like guppies, but probably less nippy than I hear gambusia are.

The issue with such a small tank is I doubt you'd have enough room for hiding spaces for the fry. But you never know. I put two of my gold female heterandria formosa and three or so males into my bucket tank (I'll show a video of that below) about a month or two ago to have them on hand if someone wanted to buy them. I tried to retrieve them, could only find one female, gave up, promptly forgot about them, and went about my business. I found them three days ago in the form of multiple visible fry/juveniles, one visible large female, and multiple visible males. Who knows how many are in there.

Here is the video of the bucket tank I mentioned. I use it to hold fish and plants that are for sale or that I don't want in my 55 gallon tank. For example I scoop out the guppies with the color least like the color I'm breeding for and put them in here. Then I take a picture of them and sell them as a 'what you see is what you get' auction. It's a useful bucket tank. And apparently heterandria formosa breed like crazy in there when it's neglected and overrun with plants. Who'da thunk it; I never meant for the bucket tank to be anything other than a holding tank but it's just packed full of fry right now. lol.

http://www.youtube.com/watch?v=-uIvjlV6Z38

Right now it looks a lot more like this

but it's functional at life support with as few plants as you see in video. The density of plants probably is what is encouraging all the breeding, protecting fry so they don't get eaten.

Oh just to be clear, I only want to put three males in the tank. No females.

Thank you so much, Erica! Your epic Pygmy sunfish thread is what got me hooked on trying Florida natives.

Oh just to be clear, I only want to put three males in the tank. No females.

Thank you so much, Erica! Your epic Pygmy sunfish thread is what got me hooked on trying Florida natives.

Thank you.

I've thought about it some more and I think three gallons is definitely enough space for three males. The 2.5 gallons or so in my bucket tank supports a breeding colony. It's all about how the space is used. The footprint is more important than the gallons. A 'long' style tank like yours or, to the extreme, a shallow setup like my bucket tank, has more liveable space than a deep tank. Heterandria formosa love surface plants. Two square feet of surface plants is two square feet of surface plants, whether they're over a 50 gallon tall or a 3.5 gallon shallow. Considering that male heterandria formosa max out at a 2 cm or <1 inch, an 18" x 6" x 7" tank is plenty of room for three of them. If you stuff the tank with plants, the three males will probably only rarely even see one another.

Heterandria love plants, period. not just surface. In a well-planted tank, feeding them is unnecessary, they pick at the vegetation and find tiny things to eat all the time. Mine will go anywhere in the water column. I saw a group of five yesterday, rooting around in the mulm in open center of my 90g, which I just measured as 16" below the duckweed cover.

And I am not sure that, in a Heter-only tank, there's any risk of cannibalization. I've not seen it, and Erika's experience of getting a bunch of juvvies in her bucket tank (where food was not being added on a regular basis) suggests that too.

I don't think a dozen Heter in a 3 gal tank would be pushing capacity. In the wild they're often packed more densely than that.

VJM, for maximum fun, stock both sexes, and let them do their thing, it will be more enjoyable watching all their normal behaviors. This must be the easiest fish in the world to keep(*), even the plastic Nemo & friends on my shelf have to be dusted every once in a while.

Also it can be very hard to catch male heterandria with a conventional collecting dipnet. They're so small and skinny they exit the dipnet as fast as water. Find out where the bigger females are, then use a regular 4x6" or 6x8" pet store aquarium net to nab some males in the shoreline greenery.

(* In a tank with lots of live plants.)

And I am not sure that, in a Heter-only tank, there's any risk of cannibalization. I've not seen it, and Erika's experience of getting a bunch of juvvies in her bucket tank (where food was not being added on a regular basis) suggests that too.

I feed my bucket tank crushed flake food twice a day.

I feed my bucket tank crushed flake food twice a day.

Sorry, Erica, my misinterpretation.

I'll use my experience then. I have Heter and/or flagfish in seven plant tanks on my back porch, and I don't feed them at all. They're fat and happy, and the Heter are breeding. (The flagfish are this year's YOY, they're not old enough yet.) However, I guess I should note that the fish are there primarily to control mosquitoes, and (unlike some buckets on the porch) there are no mosquito larva in those tanks, so presumably the fish are supplementing their diet that way to some degree.

Which reminds me, the work of a mosquito-farmer can never be neglected too long, if good relations with the wife and neighbors are to be maintained .... later !

Very interesting stuff. You have given me a lot of food for thought. The 3g is still cycling, and I want thriving plants and biofilm before any fauna goes in there. Which gives me some more time to ponder.

I had a brief infatuation with tiger teddies, but I like natives so much more. Least killis are just such cool little fish!

3g is a great size for small natives; you might look into L. ommata as well.

Well, those are very nice too! I will have to do some research on them.