Figure 1
From: Iso-luminance counterillumination drove bioluminescent shark radiation

Shark photophore patterns.
Lateral spontaneous luminescence from (a) Squaliolus aliae and (b) E. spinax. Arrows indicate photophore markings not involved in counterillumination: Pe, pectoral; Ca, caudal; Do, dorsal; Ic, infracaudal; La, lateral. Scale bars, 2 cm. (c) Etmopteridae lateral photophore markings (blue color) diversity illustrated by (from left to right): Centroscyllium ritteri, E. spinax, E. gracilispinis, E. lucifer and E. pusillus. Photographs by Mallefet. Drawings by Claes.