[Delphinus]

I don't know if this will help or not, but here goes.

When I purchased my lawnmower blenny, almost a year ago, he was a tiny little guy (about 1.5" long). I never saw him eat for ... I don't remember exactly, but it was easily 4-5 months before I ever saw him accept any offered, prepared foods. I would easily have beleived that he was not eating, except for the fact that he grew from 1.5" to 3" and then to 4" and then to 5" in very short order during this time.

Now, and here is the part that might seem to defy the claim that they are herbivores only .... during this 4-5 month period, my pod population in the tank crashed. I mean there were literally no copepods, decapods, isopods, .... none. Whereas usually when you shine a flashlight into the tank after lights out, and you see the rockwork is just crawling/swimming with bugs ... my tank had none.

I'm speculating that there was a time he only ate the bugs. I can't conclusively pinpoint the lawnmower as the cause behind the copepod population falling, but ... further food for thought is that the lawnmower blenny can now be seen eating nori on a daily basis, he is considerably larger and extremely fat. And my pods have returned. Thus, it kind of suggests to me that there might be a period of time where these fish need to adapt to offered foods. Thus .... if this is true, you need to ensure you have enough pods to be able to sustain the fish during that phase which may last several months. If not .... you may need to consider letting the fish go into a tank where this is a stronger possibility.

As they are herbivores, you probably need to be continuing to offer nori.

I found I needed to roll up my nori over a piece of PVC before he would take to it; he seemed to have no interest in a flat sheet of nori swaying in the breeze held fast by clip. He seems to need to be able to have a hard surface under the nori to be able to take any. Mine will sometimes go after free-floating foods, but I have to admit I very rarely ever see this. I have to ensure that there is a constant supply of nori in the tank.

I found mine also took several months to get used to the idea of a human walking next to the tank. Thus, perhaps if he is not taking to your nori, perhaps there is too much activity in the room that is spooking him from staying away from the nori. If this is the case, consider backing off and standing very still when feeding. Or perhaps there is too much tank activity .... are there aggressive or very active tankmakes in the tank? Perhaps he simply is too nervous to approach the nori, because it is in a spot that is too exposed.

I should mention I still only rarely see mine eating. But at least I know that he is, because he is an amazingly fat little fish. I have to sit back and watch the tank for a long period before I see him come out of hiding and start mowing down the offered nori.

These are only my opinions and speculations but maybe there is something in here that will give you something to go on.

PS. I really must reiterate the need for rolling up the nori over a piece of PVC or tubing or something, much like rolling up toilet paper over a toilet paper tube. A piece of nori floating around is not really going to work for this fish (IMHO). They are grazers of short fuzzy type algae, not really grazers of leafy algaes.