| Popis: |
An ultrastructural investigation was carried out on the cuticle, epidermis, and sensory cells in the priapulid Meiopriapulus fijiensis. Whereas the ultrastructure of the cuticle of the mouth cone and introvert principally corresponds to that of other priapulids, the cuticle of the trunk region is composed of fibrils embedded in a light matrix, has a surface characterized by densely-arranged protrusions and shows similarities to the cuticle of annelids. The epidermis is characterized by a hitherto unknown system of irregularly anastomosing channels running along the anterior-posterior axis. Integumentary structures specialized as sensilla include the first three rows of scalids on the introvert, flosculi, trunk scalids, setae, and tubules on the anal hooks. Non-sensory cuticular structures include the teeth on the mouth cone, locomotory scalids, tubercles of the general body surface, and anal hooks. |
