Spectral properties of porphyropsin from an invertebrate.

Winter crayfish (Procambarus clarkii) contain both retinal and 3-dehydroretinal, as first described by Suzuki, Makino-Tasaka and Eguchi (1984). Using the detergent L-1695 we have extracted visual pigments from the rhabdoms of crayfish and have characterized spectrally both rhodopsin (P1) and porphyropsin (P2). Both P1 and P2 are converted by light to relatively stable meta-pigments (M1 and M2). We here show a method for estimating the absorbance spectra of all four pigment species. The spectra of P533(1) and M510(1) agree with previous microspectrophotometric measurements on isolated rhabdoms. P567(2) and M537(2) represent the first 3-dehydroretinal-based visual pigment system to be characterized from an arthropod.