He looks quite happy. I'm sure he's sticking to the bloodworms 'cause he knows how to get the good food. Most animals are like that, be fussy enough you get your favorite, all the time :)
I also wanted to mention I see some clearish/white growth, which, considering the conditions you found him in, may indicate he has some new fin growth. All in all I think you've made him quite the happy lil camper.