wrote:
Could not
understand what the person was writing.

Same here. Also, with the sporging (useless emails) it's also good to
whitelist people. I have message filters set to put a star next to
people with something intelligent to say. I just added you to mine.

As for bristle worms, I'm looking to add some to one of my tanks. I've
been having a bit of detritus build up, so they are generally considered
beneficial.

It's possible that your arrow crab was weak or already dead. I can't
imagine one succumbing to worms as they can easily move away. Just like
coming across a dead animal in the woods covered in maggots. It's
unlikely the maggots killed the animal, but they are doing their role in
nature to clean up the carcass.

--Kurt