Fig. 1. (A) Absorbance spectra of visual pigment extracted from the retina of Bathysaurus ferox measured in unbleached and bleached states at pressures of 0.1, 9.0, 20.0, 31.0 and 45.8 MPa. For clarity of presentation all scans have been zeroed at 700 nm. (B) Difference spectra for each pressure constructed using the curves shown in Fig. 1A. Scans have been zeroed at the minimum long-wave absorbance (see Hart et al., 2000).