ISSN:
1432-234X
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary The ultrastructure of the epidermal layer of both the oral and arm podia of the brittle star Ophiocomina nigra is described. Despite external differences, little variation occurs in their internal structure. The podial epidermis, which is overlain by a three-layered cuticle, consists of five cell types: support, mucous, sensory, adhesive secretory and monociliated ‘neurosecretory-like’ cells. Areas of specialisation are superimposed on this basic plan. These comprise four cells forming cohesive units, made up of two adhesive secretory, one sensory and one monociliated ‘neurosecretory-like’ cells. The two adhesive secretory cells may be identical or vary in the structure of their secretory packets. The sensory cells are of the normal type bearing a short cilium with a 9+2 microtubular arrangement. The monociliated ‘neurosecretory-like’ cells contain many small dense vesicles and a short sub-cuticular cilium of irregular microtubular structure. Together, they appear to form a sensory-secretory complex which functions in adhesion both for feeding and locomotion. A system in which the secretion of the monociliated ‘neurosecretory-like’ cell may control adhesive secretion is proposed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00312471
