I just got a red tooth niger trigger fish about 5 days ago and added it to my 125gal tank with my porcupine puffer and snowflake eel. They are all juvenile still so that’s why they are in a “smaller” tank. Anyway I noticed over the past few days that my trigger will randomly twitch very fast to one side and shake his head like he is trying to get something off of him. He does it just a few times a day and the rest he spends hiding. He is eating normal and doesn’t seem to be in any distress. He does not rub against anything as would be the case with parasites I believe and the only thing I can see when examining him is a white mucas like string coming out of his eye on the side he twitches to. I will provide a picture I got of it. Also on a side not earlier during feeding time my snowflake eel was digging under one of his favorite rocks and due to this another rock in the scape fell onto the rock he was under. I was terrified he was crushed so I removed the rocks and he got up and swam under a different rock and appears fine but did not eat after as I assume he is a little stressed now. What should I look for over the next couple days to make sure he is ok.