Cleaning wrasse
Fig. 16: A cleaning wrasse (lat. labroides dimidiatus) is helping a barb to get rid of parasites. Dive #352: "Dungong Wreck", Sabang, Mindoro Island, Philippines Nikon D200; Δt=1/250 s; f=60 mm; f/5.6; ISO 100; 6 November 2009 05:43:34