Id immediately

Judging by the borrow holes in the sand I would think they came from the sand.

Maybe instead of "Trashing" them you could return them to the beach

 

what about the hermit, should i return it to the store? and is it necessarily safe to dump a bunch of stinging worms into the beach?

 

I don't think the store will take it back.

Gathering things from the beach is never a good idea. You don't know what your getting and that's never a good thing.

I'm not sure of your set up. Do you have a tank or are you just keeping things in these jars

J

 

i just keep things in jars. i can't afford an entire setup so i take really tiny animals an put them in jars.

 

it's counter-intuitive, but the smaller you go, the tougher it gets. it's tempting to save the cash. the problem is that if something goes a little wrong in a little tank, it's a big problem. there's no room for error and the parameters swing way too much.

 

There's no way to know what the worms are or what they eat from your pics or if they might have been responsible for the death of the other organisms, sorry. What you call bristleworms are more properly called fireworms. They all tend to live in rock crevices or out in the open. Those burrows are typical of sand or mud dwelling worm species.

 

is there any animal that will eat these worms? if so what is the smallest?

 

Fish, crabs, other worms, sand sifter stars, some urchins, some molluscs, & a whole lot of other creatures eat worms. Considering how many you have I'm not sure a really small predator would control them. Just scoop out the central clump of them & either pass them on to someone else or toss them.

 

UPDATE: all the worms are dead. i think it was starvation. i know there dead since massive clumps are floating or stuck in the plant. i think i will try and rescue the hermit before he dies and throw out everything else.

 

are you sure it was the worms and not a build of ammonia that is responsible for everything dying?