Eel hunger strikes

I've got two eels in two different tanks a snowflake which I've had about two years and a yellowhead who I've had for around 8 months or so. I usually feed em both two or three times per week a mix of squid, krill, silversides and clams always vitamin enriched. For the last few weeks all I had were silversides so that's all they were getting. But about two weeks ago almost simultaneously both of them stopped eating. I've had the snowflake stop taking food for a week or so before but never this long. Now I've got all the different meals for them again and neither of them are interested at all in eating. I've HEARD they can go awhile without food but does anyone know from experience? Or anyone had any luck with enticing them with anything?
No, I don't think so. I did move some rock work in the snowflakes tank but not in the yellowheads.

What's even more frustrating about this is the snowflake, when he's hungry comes all the way out and swims at the top of the tank which he's been doing but still won't eat anything
I've had it for a few months now. It's never done it before. I've had it for over 8 months and I think its gone a month and a half without eating now. I put food right up to its face and its just not interested. No matter what I try.

I've had a snowflake before this a couple years back and it never stopped eating like this.
This is actually pretty common with these guys. If you check out the articles section, there is a great write up called the care and keeping of snowflake eels (I think) and I believe it talks about hunger strikes.