MORPHOLOGY OF THROAT BARBELS OF CIRRHOSCYLLIUM-JAPONICUM (ELASMOBRANCHII, PARASCYLLIIDAE), WITH COMMENTS ON FUNCTION AND HOMOLOGY

The morphology of the throat barbels of Cirrhoscyllium japonicum is de scribed in detail. Each barbel is supported by a basal cartilage and a cartilaginous core, and innervated by ramus mandibularis externus fro m truncus hyomandibularis VII. Neither muscles nor taste buds or other sensory receptors are associated with the barbels, which are thought to function as sensory organs, responding to physical or mechanical st imulation. Comparison of the throat barbels with head appendages found in related shark groups suggests that the former are not homologous w ith any of the latter, but are better interpreted as an autapomorphic character of the genus Cirrhoscyllium.