Investigation of different ontogenetic stages of Raillietiella sp. (Pentastomida: Cephalobaenida): suboral gland and frontal gland

Abstract

In Raillietiella sp. larvae we discovered a gland whose duct pores shed their secretion caudally of the mouth onto the integument. This gland type, which we call the suboral gland, seems to be characteristic of all pentastomid species. We discuss its possible function in the invasion of the larvae into the intermediate host. Furthermore, we identified frontal gland cells and their ducts in Raillietiella and differentiated them from buccal glands and their ducts. They appear to be a general feature of pentastomids and exist even in early ontogenetic stages.