I wouldn't really expect these to eat live blackworms as those do not closely resemble their natural zooplankton diet. Live brine shrimp would be a better "starter food". I found some small frozen mysids once, but I forget the brand name, as I said, normal mysids will likely need to be diced up first.
Here is the primary issue: fish cannot be enticed to eat if there is an underlying issue that is causing them to not feed. I looked at your fish and it isn't breathing too fast, so that's good. I couldn't get a clear view, but it does seem a bit thin. Do you know this fish's history? Did it come from a LFS or did you have it shipped in? Was it feeding before you acquired it?
One underlying concern is that these fish are real "hiders" and live in deeper water. This means that the divers who collect them are under a lot of pressure (pardon the pun) to catch them as quickly as possible. In the Philippines and Indonesia, that means using cyanide to stun them. Fish collected in this manner have a much higher mortality rate than net collected ones. One of the common symptoms is lack of a feeding response...ugh.
Jay
