Distribution of CRY/PL subfamilies within the orders of Arthropoda. The occurrence rate of a subfamily within an order is given as a percentage, only percentages > 10% are shown for clarity. The total number of animals studied in each phylum is given in parentheses next to the order name. Chelicerates, crustaceans, and hexapods form the main arthropod subgroup. The major CRY/PL members of arthropods are MCRY, DCRY, and the photolyases 6-4 and CPDII. Many crustaceans also carry the DASH CRY. The four major CRY/PLs are found in all subgroups of the Hexapoda substrain, even though they are not equally abundant in all groups. MCRY is the most important CRY/PL of the hexapods. In Collembola and in individual insects of the cohort Paraneoptera and Holometabola the DASH-CRY is also present.