Fluorescence at the joint between the exopodite and flagellum of crayfish maxilliped 2. (A, B, C) The ventral strip of fluorescence at three positions of the flagellum about the exopodite. Bright field and UV images are superimposed. (A) Fully abducted. (B) Natural resting position. (C) Adducted. (D) The shape of the fluorescence at nine different angles of the same flagellum about its exopodite, from full abduction to full adduction. Only the UV images are shown. Scale bars A, B, C 200 μm, D 100 μm.