Mud-Flat Crab (Hemigrapsus oregonensis)
Since the BG was sort of dark for the crab, I tried the wand in LR3 to try to make it "Pop" a bit more. You can see the 3 spines directly behind the eye, and the lack of lines on the carapace which makes this easy to tell from Pachygrapsus, which are diurnal. This crab is nocturnal so they are active @ night and do not compete with the lined shore crab. Good to view in black.