Copepods?

[kreblak]

My skunk dottyback has shown quite a disdain for flake food of late, and won't touch the frozen stuff. However, he is growing and is active as ever. I have read that dottybacks prefer copepods. How can I tell if that is what he is eating?

[VoodooChild]

Watch him:)

[ChilDawg]

Or put a camera near the tank. :)

[mogurnda]

Although tongue-in-cheek, I agree with VoodooChild. Turn the room lights out, grab your favorite beverage, and watch the tank. You may have to do it at several times of day. Not that you need an excuse.
The nice thing about pile of live rock is that your dottyback may be eating things that eat the stuff you throw in. You may want to think about a "pod pile" or refugium, if the guy is eating only 'pods. You can also goose up production by getting some amphipods and gammarus from IPSF or Inland Aquatics. I'll add links if you're interested. Too lazy otherwise.

[kreblak]

What exactly do copepods and amphipods look like? My HOT filter (being run without media for increased water movement) is filled with small whitish things that attach themselves to the sides. They look like small grains of rice. They used to appear in the tank, but I don't see them much anymore. Are those copepods? Do I have an unintentional copepod refugium in my filter?

Edit - Voodoo, I saw that movie the other day on TV. Definitely a classic line, and ever funnier one you realize Kurt Russel is saying it to Billy Bob Thornton!

[mogurnda]

Sounds like you have "q-tip" sponges in the filter. They attach in various places and filter-feed.

'pods look like little shrimp. Copepods, at least in my tank, are very small, like white moving dots on the glass and rocks. Amphipods look like small shrimp, about 1/8" or so for the big ones. Mine crawl around in the substrate and in the macroalgae in the refugium.

What I should do, though, is go home and check my invert zoo books for better definitions.

[VoodooChild]

Check the first inch of your glass above the substrate. That's where mine are. Otherwise turn on the light after it's been off for awhile. They seem to enjoy the darkness. And yes, that's definantly a 90's classic. If I had a big black suit I'd just walk all day like a total badass too.

[kreblak]

I watched my dottyback for about an hour yesterday, and I saw him mostly harassing the damsel. However, every five minutes or so, he would stop swimming and hover about 2 or 3 inches above the substrate. He would remain relatively motionless for a moment, then strike downward and pull back to hover. Sometimes he would strike up to five times in a row. This was in a part of the tank with no growths of any kind, just open water above the substrate.

I assume that he is picking off hapless copepods?

[VoodooChild]

Sure sounds like it. If it wasn't a display of sorts in front of someone else or a parasite rub, I'd say it was 'pod picking.

[kreblak]

After watching him more, he does this striking motion a lot. Well, this explains how he has grown so rapidly while not eating any of the food I have provided.

[VoodooChild]

Do you know how to make a pile of rocks for 'pods?