Glycoproteins in the Epithelium of Lips and Associated Structures of a Hill Stream Fish Garra lamta (Cyprinidae, Cypriniformes): A Histochemical Investigation

Abstract

A series of histochemical procedures were employed to localize and characterize glycoprotein (GP) classes elaborated in the epithelia of the upper and lower lips and associated structures, namely the rostral cap, the adhesive pad, the horny upper and lower jaw sheaths and the folds of skin between them, of a hill stream fish Garra lamta. The epithelia of the lips, the folds of skin and the major portions of the rostral cap and the adhesive pad are mucogenic. The epithelia of the horny jaw sheaths and parts of the rostral cap and the adhesive pad are keratinized. Based on the histochemical characterization of GPs, the cells involved in the secretions in the epithelia at the mucogenic regions of the rostral cap and the adhesive pad comprise the epithelial cells, the type A mucous cells and the club cells. In the lips and the folds of skin, in contrast, the club cells are absent and most mucous cells belong to the type B category. Type A mucous cells are few. GPs elaborated by cellular components of the mucogenic epithelia include GPs with oxidizable vicinal diols, GPs with O-sulphate esters, GPs with sialic acid residues without O-acyl substitution or with O-acyl substitution at C7, C8 or C9 and GPs with O-acyl sugars. The different types of cells show significant differences in the classes as well as in the concentrations of the GPs elaborated by them. GPs have also been identified in the subcorneal space between the unculi and the epithelial cells in the replacement layer in the epithelia at the keratinized regions. Elaboration of more than one type of GPs suggests a basis for functional discrimination in their role in the mucous secretions at the surface as an adaptation to the feeding ecology and the environment inhabited by the fish.

Scanning electron microscopic and histological studies of the buccal cavity of a phytoplanktivorous small freshwater fish, Amblypharyngodon mola

“…Mucous also serves as protecting layer in nature (Whitear, 1990). Mucous cell secretion is an adaptation to lubricate the epithelia and thereby protecting the epithelia from abrasive as well as inhibition of microbial progression (Pinky, Mittal, & Mittal, 2008). Thus, in A. mola, their presence in the upper and lower jaws protects these surfaces during feeding.…”

The Pharyngeal Organ in the Buccal Cavity of the Male Siamese Fighting Fish,Betta splendens, Supplies Mucus for Building Bubble Nests

“…The major constituents of mucus are glycoproteins (Shephard, 1994). Previous studies have revealed that periodic acid-Schiff's (PAS) staining can label all types of mucous cells in the epithelium of teleosts (Gona, 1979;Yashal et al, 2007;Mittal and Mittal, 2008).…”

The Changes of Mucous Cells in the Skin of Van Fish [Alburnus tarichi (Güldenstädt, 1814)] during Freshwater Adaptation

“…Balıklarda deri, solungaç ve sindirim kanalı gibi organlarda farklı tiplerde mukus hücreleri mevcuttur (Pinky & Mittal, 2008). Balıkların nötral, asidik veya sülfat içeren farklı glikoprotein özelliklerine sahip mukus hücre içerikleri yaşadıkları ekofizyolojik çevre ile ilişkilidir.…”