Who Gives A Fish Forums

I'm taking a shot in the dark here, but I thought I'd ask anyway. My Duncan frag has 6 heads that usually get huge, but for the past week or so, they've been staying almost completely closed. This isn't the first time it's happened, and since the rest of the tank looks fine, I wasn't too worried. But tonight, while messing with the tank, I accidentally knocked the Duncan out of its spot in the rock and caught a glimpse of a few tiny, dark grey critters - they were super small, about the size of a comma. They vanished before I could get a better look. The Duncan itself looks fine, no damage on the stalk or heads, but I dipped it just in case. We haven't added anything new to the tank in a while, and definitely not without QT, so I'm stumped as to where these tiny critters came from. Could they be some kind of parasite affecting the Duncans, or were they just random hitchhikers living in the rock?

Any thoughts on this?

Copepods are my guess, pretty common and tiny, fits the description.

No need to stress about it then, appreciate the feedback

I'm inclined to agree with felinxo that the tiny critters you saw are likely copepods. I'm curious, though, how your Duncan is faring since my own has been experiencing a similar "cycle" lately. It would occasionally close up, but over the past three days, it's been closed more frequently and for longer periods.

My Duncan's heads are opening about halfway now, and they still react when I target feed them, so I'm pretty sure it's just going through one of its cycles - I've seen it before, and it usually takes a couple of weeks to fully recover. It's still responding to food, which is a good sign, and it's not showing any other signs of stress, so I'm not too worried. I'm still a bit new to all this, but from what I've observed, this seems like normal behavior for my Duncan.