Porcelain Anemone crab appears to be dead, and pictures

While investigating my tank by flashlight, I found what appear to be the remains of the Porcelain Anemone crab (Neopetrolisthes ohshimai). Specifically, I can see the claws, hollowed out. I still wonder if I have an aggresor in my tank.

Removed the bag of the carbon rods (that come with the Nano Cube) from the filter area.

Bumble-bee Snail (Family: Pusiostoma) and a hitch-hiker snail (top right, stripped):

I know its difficult to see, but this a two-tentacled Hair worm (Spionids), its tube is made of debris "glued" together.



Orangeclaw Hermit Crab (Calcinus tibicen) and a hitch-hiker snail (bottom left, stripped):



Small (perhaps 1") bristle worm:



The "remains" of some of the pulsing xenia (Xeniid) as it "moved" over some of this brown kelp, has now grown into a small stalk of its own right.



Star Polyp colony (Order Zoanthidea/Zoanthids):



Sponge (from Josh):



Orangeclaw Hermit Crab (Calcinus tibicen):