Fig. 6. ERGs recorded to UV stimuli at 330 nm, 350 nm and 370 nm to increasing (top to bottom) stimulus intensity. ERGs recorded to UV stimuli at 330 nm, 350 nm and 370 nm to increasing (top to bottom) stimulus intensity. ERGs at 330 nm and 350 nm are similar in amplitude. ERGs at 370 nm require less energy to elicit a response of similar amplitude. ERGs at 370 nm are double the amplitude of ERGs at 330 nm and 350 nm. Data are representative for all animals. Insert: ERGs to UV stimuli (370 nm) at increasing temporal frequencies (top to bottom). Responses are clear from 1 to 10 Hz but undetectable at 15 Hz. Similar data were obtained from two animals. Rod mediated responses do not extend beyond 15-18 Hz (Hecht and Shlaer, 1936: Kelly, 1974). Hence, responses here were limited to rod function. Chris Hogg et al. Biology Open 2015;4:812-818 © 2015. Published by The Company of Biologists Ltd