Study of the Adhesive Organ and Associated Structures of <i>Glyptothorax ngapang</i> (Teleostei: Sisoridae) From Manipur, India Using Light and Scanning Electron Microscopy

The current work represents the scanning electron microscopical study of the adhesive organ and its associated structures in the hill stream silurid Glyptothorax ngapang Vishwanath and Linthoingambi, 2007 from Manipur, India for the first time. The inverted "U"-shaped thoracic adhesive apparatus of the fish is located between the bases of its pectoral fins on the ventral side, just below the operculum. The apparatus had longitudinal ridges and grooves in the scanning electron microscopy picture, and the posterior base had a slightly concave triangular depression. The ridges were seen with spiny tubercular projections or the unculi of varying shapes and sizes. Grooves were devoid of any glands and such horny structures. Mucous gland openings were seen in the median depression of the apparatus as well as on the general body surface. Skin appeared rough due to the presence of numerous plaques. Tubercles, papillae, and receptor organs surrounded by numerous microvilli were seen around the snout region.