Tiger tail cucumber: Eating mushrooms?

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I have had a tiger tail cucumber for a few months, he is only a few inches long and he hides under one rock all the time.

Lately I have had some disappearing mushrooms. Three striped mushrooms were on a small rock near the cucumber's lair, one morning the rock was turned over and the mushrooms were all shrivelled up, the next day the mushrooms were gone.

Nearby there was a big colony of hair green mushrooms, lately they are withering away, hairy green mushrooms elsewhere in the tank look fine.

I wonder if the cucumber is to blame or if there is another predator eating these mushrooms.