Morphology and ultrastructure of the infrabuccal pocket and its lining epithelium in workers of Ectomomyrmex javanus (Hymenoptera: Formicidae)

This paper describes the morphology and ultrastructure of the infrabuccal pocket in workers of the carnivorous ant Ectomomyrmex javanus, using SEM and TEM. The infrabuccal pocket is a flexible bag with a diameter of 330 ± 30 μm. In its anterior part, the pocket wall reaches a thickness of 24.45 ± 3.45 μm, which is thicker than the wall lining the rest of the infrabuccal pocket, where it measures 6.87 ± 1.12 μm. The epidermal cells of the wall form a thickened epithelium with a thickness of 10.18 ± 2.50 μm. There are different kinds of hairs inside the pocket, that help in filtering solid pellets. Literature data on the infrabuccal pocket are limited and the function of the thicker epithelium is not yet known. It may provide mechanical strength as the pocket undergoes daily size changes because of the filling up and spitting out of pellets.