SPIRACULAR PLATE OF NYMPHAL AND ADULT HARD TICKS (ACARINA, IXODIDAE) - MORPHOLOGY AND CUTICULAR ULTRASTRUCTURE

摘要

Morphology and ultrastructure of the nymphal and adult spiracular plate of five species of hard ticks (Ixodidae) are described using scanning and transmission electron microscopy. Both the surface area and the number of aeropyles increase significantly between the nymphal and adult stages and are greater in females than in males. The spiracular plate is divided into four regions: an outer cuticle with aeropyles, a labyrinth composed of cuticular pedicels and chambers, a thick basal plate, and a cellular layer. The pedicels that separate the chambers of the spiracular plate have a large central channel, surrounded by smaller secondary channels. These channels are found throughout the basal plate cuticle and contain a granular substance, probably secreted by the epidermal cells. The basal. plate gland is enclosed by the cuticle of the basal plate and is dispersed randomly in the basal plate. This gland has duct and secretory cells, and the duct has a valve-like portion at its apical end where the gland opens at the base of a chamber. The basal plate gland cells and epidermal cells beneath the basal plate contain many free ribosomes, lipid droplets, rough endoplasmic reticulum, and mitochondria. The glands may be involved in the regulation of water loss and air diffusion. [References: 28]