The fine structure of the coxal glands in Myobia murismusculi (Schrank) (Acari: Myobiidae).
The coxal glands of M. murismusculi consist of the proximal tubular portion (tubulus), the distal glandular sac and the terminal excretory duct. The tubulus comprises looped proximal and distal tubes that run in close association with each other. The cells of the proximal tube form numerous short protrusions that project into the neighbouring organs through the pores in their basal lamina. The sac is a distal part of the gland and so it cannot be considered as a homologue of the proximal filter sacculus of other arthropods. A large number of pinocytotic vesicles and lysosome-like bodies in the epithelial lining of the sac imply that the main functions of this organ may be the absorption of substances from the lumen of the gland and their subsequent intracellular transformation. In addition the sac of females was shown to produce dense secretory granules. The ultrastructural features of the glands are discussed and compared to other representatives of Acari.
Filimonova
Svetlana A
SA
Zoological Institute, Russian Academy of Sciences, 199034 St. Petersburg, Russia.