4 replies to this topic

[Kanus]

So about two years ago I ordered a half dozen or so wild-caught flagfish from Aquabid. These fish were half-grown, and after a bout of fin rot, I lost one of them, and the rest went into my 75 gallon in the living room. They were just starting to develop sexual dimorphism at this point and it appeared that I had a single male and 4 females. These fish have been very happy, have grown to be among the biggest flagfish I've ever seen, and have been spawning in a big clump of baby tears basically the entire time I've had them.

Despite their predictable spawning activity, putting them in a patio pond for 2 months last summer, or grabbing a clump of baby tears after they spawn has resulted in exactly 1 fry I attempted to raise and failed (so if anyone can help me with that it'd be appreciated!)But this is a derail from my original topic.

I was looking at them yesterday and noticed one of the females has a bit more of an iridescent green sheen to the spot on her flank. Attempting to isolate which one I was looking at, I got a better look and noticed the fins appeared a little longer than they should be, and had very faint red and blue markings. I'm now certain that I actually have 2 males and 2 females in this tank, rather than the 1 male/3 females I had thought for the past 2 years.

Does anyone know if killifish are capable of going through mid-life sex changes? Or perhaps this was a male all along disguised as a female, acting as a sneaker male or something similar? Perhaps he has decided he is big enough to challenge the dominant male and is morphing into his male characteristics to attempt to take over the breeding group? I've never heard or this sort of thing with killifishes. They all seem to develop dimorphic characteristics early in development and, as far as I know, stay that way.

Any ideas?

[Matt DeLaVega]

I have no clue, but this sounds very interesting.

[Michael Wolfe]

Derek, we can talk more next week, but my basic advise on raising Flagfish is to put 'em outside and then try to make plans on what to do with the extra 25 fish that you will get.

[smbass]

My experience is similar as far as breeding them. Put them outside and just let them do their thing and you won't know what to do with them all. Gar like them when you have several hundred. Guess it all just is scale. In my case it was 15x15' rubber lined pond. As far as your sex change I have no clue. I have noticed that females keep the black spot on the dorsal that it seems all juveniles have. I always used that to sex them aside from just color.

[littlen]

A 20 tall, lots of ceratophyllum, and 1.2 adult Flagfish was enough for to increase their numbers to about 15 or so over the course of a year.  The adults bred by scattering their eggs on some java moss on the bottom.  The fry scooted along the bottom (I had sand at the time) for a few weeks before venturing up into the water column.  I didn't do much to rear them other than provide lots of habitat for them to hide, and additional food (microworms and BBS).  The adults didn't bother the juveniles once they were about 1cm in length----if they even saw them.  I think the population plateaued as the juveniles were able to hunt the fry.

 

I also had 5 Flagfish to start with but pulled a pair off to another tank shortly after receiving them.  So I wasn't able to witness anything that you described.  Could you post some pics of all of them?  My experience with the females is that they remained bland and unremarkable in regards to their colors the entire time I had them.  But I think you are on to something with the potential sex change theory.  I'll say again in the words of Dr. Ian Malcom, "Life,....uh, uh...finds a way".