The tentacles of Ichthyophis (Amphibia: Caecilia) with special reference to the skin

The skin of the paired tentacles of Ichthyophis consists of a cornified epidermis of 5–7 layers of epidermal cells, and a glandular dermis of ducted mucous glands, in association with collagen, blood vessels, fibroblasts, granulocytes, sparse melanophores and characteristic laminophores of unknown function. The epidermis is highly innervated at all levels below the stratum corneum by naked neurites, which originate as branches from large unmyelinated nerve bundles (and associated Schwann cells), located sub-epidermally, and which are part of the trigeminal cranial nerve. Myelinated nerves are also present below the epidermis, spatially associated with capillaries and glands. The study of the ultrastructure of the tentacle supports a concept of a sensory function, possibly tactile, though until further information from experimentation is available, any ideas on the specific nature of these sensory activities must remain speculative.