Who Gives A Fish Forums

I've had my royal gramma for a while, and it's been doing great, but its behavior has changed pretty drastically over the last two days. It used to run to me every time I walked past the tank, begging for food, and would even eat from my hand - every single time, I kid you not. Now, it just eyes me from a distance, only coming out when it's really hungry, and the rest of the time it darts away. I've noticed it's scraped itself and lost a few scales on its back near the dorsal fin, probably from darting into a narrow, sharp-edged hole in the rockwork next to what I can only describe as its "nest".

Over the last two weeks, it's started building these little round mats of Chaeto, neatly arranged on the substrate and rocks. It's been sticking pretty close to these, and I just caught it doing this tail-fanning behavior over its latest nest that looks a lot like what I've seen in spawning behavior in other male fish species. I thought maybe this weirdness was due to some sort of spawning behavior, but the only other fish in the tank is my antisocial engineer goby...so I'm thinking there might be something else going on that's making it skittish. Is this sudden personality change something expected with royal grammars, or is it likely a reaction to some sort of problem, like whatever happened to its back?

Lining pits with algae, as you've observed with your royal gramma, is indeed characteristic of their spawning behavior. It's possible that your fish is a female and has laid eggs, although in the absence of a mate, these eggs would not be fertile. I've had a similar experience with a freshwater fish that spawned solo, so it's not entirely unheard of in the aquarium world.

Thanks for the insight, zenoxa. That behavior's definitely been explained now. It's created several neat little mats of Chaeto, but unfortunately my urchin's had a go at a couple of the older ones. Now I just have to hope that my gramma regrows those lost scales.

I'm inclined to think it's spawning behavior too. The lack of another Gramma is a bit unusual, maybe your royal gramma is feeling a bit isolated.

I find it fascinating that royal grammas would still exhibit such strong maternal instincts, going to the effort of caring for eggs that have no chance of hatching.

If there are indeed eggs nestled within that latest mat of Chaeto, the urchin or tiger cowrie will likely put an end to this behavior soon enough, once they find their way over to it. I've often found myself wishing for a larger tank, where I could attempt to find a suitable mate for my royal gramma, but I'm hesitant about introducing another one, given their territorial nature - it's a prospect that doesn't fill me with confidence, especially considering the potential risks and stress it could bring to both fish.

I'm considering adding a cleaner shrimp to the tank, given how often my royal gramma ends up with debris stuck to it from hiding in the rockwork. I'm not sure if it's a species that would actually go get cleaned, though - my engineer goby never let the shrimp clean it when I had one before. On the flip side, a small cleaner shrimp might not make a huge difference in this case. The good news is that the color is starting to come back to the scratched area, at least. I just can't help but feel a bit paranoid when I see my gramma popping out of the live rock looking like it's been through a dust storm.