Studies on the Indian sand lobster Thenus orientalis (Lund): mucopolysaccharides of the tegumental glands.

The tegumental glands are imbedded in the connective tissue below the epithelium of oesophagus. Each gland is made up of cells which are conical in shape with their narrow ends directed towards the lumen of the gland. In the centre of each gland there is a cavity which communicates with intracellular duct. Similar glands have been found in the hind-gut region also. These glands secrete both acid and neutral mucopolysaccharides and to some extent glycoproteins. The glands are charged mostly with the task of secreting weakly acidic mucopolysaccharides and neutral mucopolysaccharides which are confined to the apices and central cavity of the gland. The acidic nature is partly due to sialic acid and partly due to hyaluronic acid. These weak acids do not seem to play any role in digestion but lubricate the lumen of the oesophagus for easy passage of food and keep the lining of the oesophagus slimy. In the hind-gut they help in binding the faecal matter into pellets.