I’m including these in one category as I’ve only kept Flounder and Dab so far and there seems to be little point in doing separate features when there is no real difference in behaviour. I say I’ve kept Flounder and Dab, but I’m guessing really as I’m not 100% what they are as they’re juveniles and its difficult to tell.
They’re a great addition to the tank though and fascinating to watch. The first to go in was what I believe to be a little Flounder. I kept it in a breeding net for a few weeks before it went in the main tank, as I wanted to grow it out a little as I was worried it might get sucked into the overflow tray.
He was growing steadily but I wasn’t ready to put him in the main tank, he made that decision himself y jumping out of the net during the night and into the tank. I came down in the morning and couldn’t find him in the net. Then I saw him casually swimming about with the gobies. He’s done well in there, but he isn’t growing much despite eating plenty.
A couple of weeks later I added three more, which I think are Dabs but won’t know until they grow a bit. One of them is bigger than the others so all being well I’ll be able to identify it properly soon enough. They’re active swimmers and don’t just sit on the bottom all the time as I thought they would. Often they’ll attach themselves to the glass like a Plec.
They are active at feeding time but they aren’t aggressive feeders like the Blennies and Gobies, so it’s important to make sure food is placed in front of them so they definitely get a decent share. Small ones are great for this kind of set up, but larger ones could be problematic as they’d almost certainly make short work of the prawns, and possibly even the Gobies.
The only problem I have encountered with them is that in the middle of summer when the water temperature rose during a heatwave (it got up to 27.4 degrees), the flatties didn’t seem comfortable at all. They were swimming up to the surface and then back down again repeatedly. They continued to feed, but they just seemed agitated.
This is understandable, as unlike everything else in the tank, they aren’t naturally a rockpool species. You will find the baby ones in sandy pools at low tide, but it isn’t where they reside permanently. The Flounder came from one of those sandy pools but the other three (Dabs?) were caught in a push net in the Mersey, whether the temperature is always going to be much lower than pools at low tide.
So while there have been no casualties and they seem to be doing fine, they certainly don’t do as well with temperature fluctuations as a Blenny or a Goby does, for instance.
