[harriw]

Can fish (these are yellow labs specifically, but I think this question could apply to just about any fish we keep) tell when another fish is sexually mature?

I have three yellow labs right now. They're all on the smaller side (I was surprised at first to see courting behavior already), which brings up the question of how many of them are actually mature. Although I have not vented them, based on behavior I believe this is what I have:

1. What is clearly an alpha male
2. What I believe to a female yellow lab/red zebra hybrid
3. smaller lab with "feminine" markings (no black at all on lower fins, no black bar on eyes) that I think is a sub-dominant male.

My alpha male constantly chases, nips, and "shimmies" for the hybrid, presumably trying to get her to mate. She wants nothing to do with it, at least so far. He's definitely larger than she is, which I'm taking to mean he's older as well. I'm wondering if she just isn't interested for any of a million reasons, or if perhaps she's not sexually mature yet and he just doesn't realize it?

On the other hand, he leaves the little guy alone except for evicting him from a cosy cave once in a while (won't chase him across the tank afterwards like he does the hybrid, though). I also catch the hybrid chasing this little guy once in a while - he's definitely at the bottom of the pecking order. I got the little guys (there were 2 of them at first, lost 1 to ich ) hoping to spread out alpha's aggression some, but it didn't seem to work. I'm wondering if tiny is just a sub-dominant male, or if perhaps it is a female, and my alpha knows she isn't mature enough to mate yet, and leaves her alone?

So, I'm thinking: 1.) Alpha CAN tell maturity, the hybrid simply isn't interested in him, and little guy is either male, or immature OR 2.) He CAN'T tell, hybrid isn't mature and therefore can't mate, little guy is a male. All I know is that alpha is definitely interested, and hybrid does not seem to be. This situation is making them both rather frustrated.

So, if I get more labs to try and spread out aggression again, am I ok getting the little guys again (I like to watch them grow up, and they're cheaper that way anyway), or will big guy know they're immature and continue chasing the hybrid? In that case, I'd look for some larger ones (hopefully females) to keep the boss happy and give the hybrid a break.

I know I should not let any fry from these guys out into the world based on my fear that mommy was a hybrid, but I'd like to know what's going on here, and what direction I should go in, and whether or not I should be expecting fry any time soon.

Thanks a lot!

-Bill

 

[cichlidaholic]

Yes, fish know when other fish are sexually mature.

IME, it seems my male knows days before the female knows that she is ready to spawn. You can tell with a female most of the time by looking at the vent area. The oviposter will be slightly enlarged, much like a pimple in the genital area, for a few days before the actual spawn takes place. (You may see enlargement in the same area on the male during and after the spawn for a couple of hours...)

Now, with your yellow labs, you may be right on the "alpha male". But...They can easily fool you, and size, finnage, absence or presence of black, etc. don't really mean a thing.

I've had females much larger than my males. I've had females with stunning finnage, including black on the pelvic and anal fins.

Larger mbuna typically ignore younger mbuna, and I believe it to be for the very reasons you state...They aren't a threat or anything to be excited about, because they aren't sexually mature. (That's why sometimes adding fish as youngsters doesn't really help with overstocking to even out the aggression - aggressive fish tend to pay no attention to the young ones!)

The hybrid (yellow lab/red zebra) is a wild card I would remove from the equation. You can't trust the temperament of this fish, and it will breed with anything in the tank, causing bigger problems for you down the line. Overall, it will likely only cause more chaos in the tank as it matures, and it sounds like you've reached the point where you're ready to eliminate all the chaos that you can.

It's a great idea to add more yellow labs. If you remove the hybrid, you might see a different relationship between the two remaining "older" Yellow labs. I think I would try to find adults or sub adults if possible, just because the one larger Yellow lab seems to be a bit of a tyrant, because I agree with your theory that adding little ones isn't going to make much of a difference until they mature.

Yellow labs do much better in larger groups, and they grow quickly, so if you can only find smaller ones and remove the hybrid, things may calm down enough to buy you some time for the little ones to grow up. (Adding or removing one fish can make all the difference in the world in a tank!)

HTH

Kim

 

[harriw]

Thanks Kim,

How would you go about "removing" a hybrid? This is the only tank I run at the moment, and I can't imagine there's much demand for hybrids out there.

Is it considered humane/acceptable to euthenize hybrids? She didn't choose her parents, after all... :?

-Bill

 

[cichlidaholic]

When I first started keeping cichlids, one of the first two that I bought turned out to be a hybrid...He was beautiful, but I couldn't keep him in my main tank because he tried to spawn with everything in sight.

I got a larger tank and moved him to the smaller one for awhile, but eventually I realized I didn't want to devote tank space to one or two unwanted fish.

I euthanized him, but it took me awhile to come to terms with it and do it.

I couldn't take him back to the LFS, because then someone else would just wind up with him.

I also had to euthanize alot of his fry, which was equally hard, but it helped me to make the final decision. It would have been easier to euthanize him at the beginning than to deal with his unpredictable behaviour for as long as I did.

Kim

 

[harriw]

Thanks for the help Kim!

Just a quick update - I found a cheap used 10G setup that I've put together as a quarantine/hospital tank. I pulled out the hybrid and am using her to cycle this new tank for now - 2 birds with one stone.

Do you think this is a decent long-term solution, or would I just be torturing the thing keeping it cooped up in a 10G (by herself, other than temporary tankmates in quarantine/treatment)? Is 10G enough for a single cichlid?

-Bill H

 

[DJRansome]

It probably would not be happy in a 10G, but in addition, you will have the problem of what to do with it when you need the hospital for holding Mom or fry, or when you need it as quarantine for new fish.

Living through a cycle with fish is not going to make the fish happy either. The ammonia and nitrite spike can permanently damage their gills, etc. If you've got an established tank, add filter media from the established tank to the 10G and instant cycle.