Fig. 2.

Images of sensory structures of live Symsagittifera roscoffensis. a Hatchling. Arrowheads point to eyes, arrow to statocyst. Note absence of symbionts and presence of orange rhabdoids. b Anterior end of adult with symbionts and rhabdoids. White arrowheads point to eyes, white arrow to statocyst, black arrow to frontal organ. c Eye of an adult. Asterisk marks nucleus, arrowhead points to concrements. d Statocyst of an adult. Abbreviations: l lithocyte; p parietal cells. Scale bars: a 100 μm; b 50 μm; c 10 μm; d 10 μm