A study of visual pigments in the two antarctic crustaceans Orchomene plebs (Amphipoda) and Glyptonotus antarcticus (Isopoda)

Abstract 1. 1. Total chromophore contents as well as the contributions made by 11- cis retinal were determined by high pressure liquid chromatography in light- and dark-adapted eyes of Orchomene plebs and Glyptonotus antarcticus (Amphipoda and Isopoda, respectively). 2. 2. In O. plebs the highest amount of total chromophore in pmol/eye was found to be 18.5 in 36 hr dark-adapted animals. The lowest amount (11.6 pmol/eye) was recorded in 24 hr light-adapted individuals. 3. 3. In dark-adapted O. plebs , irrespective of whether dark-adapted for 36 or 60 hr, the percentage of 11- cis retinal was maximally 96.6%. In the light-adapted material it reached 71.2% 4. 4. In eyes of 20 hr dark-adapted Glyptonotous antarcticus , possibly because of insufficient dark adaptation, a total chromophore content of only 3.2 pmol/eye was found. The percentage of 11- cis retinal was 55.8. 5. 5. Porphyropsin with its testable 3-dehydroretinal (vitamin A 2 -aldehyde) was not encountered in any of our samples. 6. 6. Calculations of photopigment per gram body weight and a comparison with data from freshwater crayfish show that dark-adapted O. plebs possess approximately 20 times the relative photopigment amount of the crayfish. Absolute sensitivity of the eye of O. plebs is, therefore, expected to be very high.