Subadult California beach hopper; Orchestoidea californiana. Adults lose the dark saddles on the back and the longer pair of antennae turn reddish. Beach hoppers are frequently amazingly abundant. This species prefers intertidal deposits of seaweeds. Beach hoppers are Amphipod crustaceans in family Gammaridae. It can be found from Vancouver Island south to central CA. Photo taken Fort Warden State Park, Olympic Peninsula; WA.