Hard to see but you are at risk with mostly all crabs except and emerald, however, if hungry, crabs are opportunistist and may seize the slow movers or non movers. As DaveK said, remove.
Glass trap maybe although this never worked for me.
Obliterated one with a fork and the fish cleaned up.
Unfortunately another lesson in keeping pest out.
LFS live is generally not clean of pests.
Sorry bout that!