Fine structure of the myenteric and submucous plexuses in the stomach of a coral fish, Chelmon rostratus Cuvier.

The fine structure of the teleostean myenteric and submucous plexuses has been studied in the stomach of the coral fish, Chelmon rostratus Cuvier. The myenteric plexus is a prominent loose mesh containing nerve cells, myelinated and unmyelinated axon profiles, vesiculated axon profiles, Schwann cells, collagen and capillaries. Unmyelinated axons greatly outnumber the myelinated ones. Vesiculated axon profiles were uncommon, and synapses were rarely observed. Compared with the myenteric plexus, the submucous plexus was more modest in size; it was devoid of nerve cells and myelin sheaths were only occasionally seen.