black racing stripe?

[OrandaMan]

After adding a fish to my tank that has my Boesemani rainbow in it, he suddenly gained a narrow black stripe one both sides from head to tail. What the heck is that?

[Complexity]

May be a stress stripe. Sometimes fish will darken or have stripes darken (where there were no stripes before) when they're stressed.

Watch the fish carefully to make sure there is no actual threat. Your fish should go back to normal coloring once it feels safe again.

[OrandaMan]

Thanks. I think he was doing a dominance thing. He kept harassing the poor paradise fish, but I think it's settled for now. You were definitely right, because the stripe has faded.

You know, he can be really cute. Sometimes I would catch him being a little too aggressive, so I'd point at him and say, "now stop that." He'd come up to the aquarium all sheepish and leave the other fish alone for a few. I love this guy.

[Complexity]

He sounds really cute! But I am a little concerned about him. To be clear, you're saying your Boesemani rainbow is the fish behaving this way, right? Stress colors, dominance, and aggression aren't words normally used to describe a Boesemani rainbow. Is he part of a shoal (school) or by himself? If he's by himself, can you add more to the tank so he can be part of a shoal? He should not be by himself. If he is, that would explain the stress colors and aggression. It means he's very scared. Shoaling fish do not feel safe if they're by themselves.

[OrandaMan]

I had read that a single Boesemani generally only has problems with aggression when something of its size is added and dominance needs to be established. He hasn't seemed unhappy, really, but I know you're right. The thing is the room for them.

Here's a thought, though: you may have seen my other thread where I was asking advice on what to add to a 15 gallon tank after I've set it up and cycled it. What if, along with the German blue ram and the school of cardinal tetras, I add to it my school of five Von Rio tetras (maybe plus one more) and get rid of my six harlequin rasboras? Without the six rasboras and the five Von Rios, I might have enough room in the 29 gallon for a school of Boesemanis. The other fish in there are two platies (could possibly move those to my 20 gallon unheated tank), the new paradise fish, a honey gourami and two gold dojos (to be moved to the larger goldfish tank when I pay it off next month). Considering that, would I have the room for two more male and three female Boesemanis? Let's see, that would make it the honey dwarf, the paradise fish and the six Boesemanis (and temporarily the dojos). The 29 gallon tank is big enough for that, isn't it?

If this will work, I'm going to have to find a home for my six rasboras. One of them is full of eggs, but I'm going to try to induce spawning today. Maybe. I wouldn't mind giving them away, though I'd miss them (they love to watch me when I'm lying down ).

Anyway, what do you think?

[Complexity]

I'm a bad one to ask about fish stocking because I overload my tanks considerably. My first reaction is that you don't have to get rid of the rasboras. It's not as if they're big fish that create a lot of detritus or take up a lot of space. We are only talking about 6 of them.

What's more important is the tank's environment and maintenance. Are there live plants? If so, you can crowd in more fish than without live plants. How often do you change the water? If changing 50% every week, then you can crowd in more fish. Otherwise, it's better to have fewer fish.

The concern (other than aggression -- do the fish get along -- and physical space for the fish to swim) is water quality. A healthy, cycled tank should have enough bacteria to convert the ammonia into nitrites and then nitrates. Nitrates then becomes the concern. If live plants are in the tank, they'll use the nitrates which then lowers the nitrates in the tank. That's one reason why a planted tank can crowd in more fish than a non-planted tank. Secondly, if large, weekly water changes are regularly performed, then nitrates are removed, keeping them at a healthy level. However, for anyone who either doesn't want to or cannot (due to schedule or health) do weekly water changes, then it's best to put fewer fish in the tank. That way there's less detritus being pooped into the tank which means less nitrates being produced. Therefore, nitrate levels rise more slowly so water changes can be performed less often.

So how can you tell is your tank can handle more fish? One way is to test the nitrates before water changes for a couple of weeks. How high do the nitrates increase between water changes? If they increase to an unsafe level, then do not add more fish without first finding a way to decrease the nitrate levels (more frequent water changes, change more water each time, decrease amount and frequency of feeding). If, however, the nitrates are still pretty low, then it's safe to add more fish. Keep in mind the fish's ultimate size when checking for nitrates.

I think you can add the extra rainbows to the tank even with the rasboras, but be sure to test the nitrates before making that decision. The nitrates will tell you whether you can and cannot add more fish.

[OrandaMan]

Thanks so much. As it happens, I had some wisteria, a red crypt, a java fern (doing badly... I might remove it or bury it for mulch) and a big, beautiful Amazon sword, but have just added a bunch more plants from my order from aquaticplantdepot.

I've gone ahead and offered the rasboras in the market under free stuff. Might as well leave it there. But you have given me an idea. From what I understand, Fish Gallery sometimes stocks galaxy rasboras and I've wanted to give them try. I could go ahead and put the Von Rios in the 15 gallon once it's set up and give them a few more and add the cardinals to the 29 gallon. Hmmm. Set the 15 up with 8 Von Rios, the German blue ram and the corydaras that Mzungu mentioned. Heck yeah. This will be awesome.

[OrandaMan]

Oh, and yeah... my nitrates have been pretty darn low. I think I can do it.

[Gapzero]

how deep is the 15 and what cory's were you thinking?

[OrandaMan]

It's one foot deep. As far as what kind of corys, I looked them up and they're pretty nice, but I'd take a look at what's available at a few lfs.

[Mzungu]

how deep is the 15 and what cory's were you thinking?

Here's the thread. :)

http://www.houstonfishbox.com/vforums/showthread.php?t=31455

[Gapzero]

Cool, well make sure whatever cory you get, that they are a school of at least 3 to 5, no less. Also no pigmy ones. and also the harlequin rasbora is Trigonostigma heteromorpha, the lamb chop rasbora is actually different it is Trigonostigma hengeli

[OrandaMan]

I had no idea they were a different species. They can't interbreed? If they can, it seems rather arbitrary to categorize them differently.

[Gapzero]

They probably can, they just choose not to. Also, even though they look close to each other, there are many differences that make each one it's own individual species. Like to most people Corydoras Metae and Corydoras Melini look the same. But the Metae has a solid black stripe up the back, and on Melini it breaks at some point to show body color, creating two short black stripes.

[OrandaMan]

As I wrote in the other thread, I'm fairly sure from the links Complexity posted that they're all harlequins. The red tint seems to indicate it. I also looked again and they all have the same reddish tint on the ends of their fins.

I bought them all as heteromorphas, so if they're not, the store got it wrong. That may be, though.