INVESTIGATION OF THE INTESTINAL SPHEROCRYSTALS OF DIFFERENT CEPHALOHAENIDA (PENTASTOMIDA)

The midgut cells of cephalobaenid pentastomids contain spherocrystals varying in size and appearance between the genera. Iron was detected i n the vicinity of the crystals in all three genera, being considerably fainter in Reighardia sternae than in the other species. Ultrastructu rally a distinct lamination of the spherocrystals was evident, being f aint in R. sternae but clearly expressed in Raillietiella hemidactyli and Cephalobaena tetrapoda. According to the species, their diameter r anged from 1.3 to 6.25 mu m. The size and number of the crystals were highest in R. hemidactyli and lowest in R. sternae. The inclusions wer e formed in the endoplasmic reticulum and migrated toward the cellular apex, accumulating there and being expelled into the midgut lumen. As determined by energy-dispersive X-ray analysis, calcium turned out to be the main component of the crystals. Furthermore, small amounts of chlorine and iron could be traced in the crystals. The relevance of th e crystals is regarded as a kind of storage excretion such as that pre sent in many other arthropods.