THE ROLES OF HEMOCYTES IN TANNING DURING THE MOLTING CYCLE: A HISTOCHEMICAL STUDY OF THE FIDDLER CRAB, UCA PUGILATOR.

Histochemical data support the previous biochemical finding that the blood is a major site for the production of proteinaceous and diphenolic substances for tanning of the cuticle in the fiddler crab, Uca pugilator. Five types of hemocytes are described. Specifically in tanning, the hyaline cells (cystocytes) appear responsible for the production of diphenolic tanning agents whereas the granulocytes synthesize the proteins involved. Other types of hemocyte may be transitional forms involved in clotting (intermediate cells). Various histochemical reactions for each type of hemocyte and the cuticle are recorded throughout the molting cycle, and appear cyclic. The data suggest there is hormonal control of the cyclic events during the tanning process.