Skin mucus N-glycolylneuraminic acid relates to mucous cell parameters in Atlantic salmon
Grigory V. Merkin1*, Anette Sauve2, Mearge A. Okubamichael1, Trond-Inge Kvernevik3, Karin Pittman1,4**
Grigory V. Merkin1*
Anette Sauve2
Mearge A. Okubamichael1
Trond-Inge Kvernevik3
Karin Pittman1,4**
Sialic acids (Sias) in fish skin mucus play a crucial role in mediating interactions with the surrounding environment, serving as key components of the protective mucus that coats the fish. Sias contribute to the physical and chemical barriers that protect fish from pathogens and support mutualistic relationships with bacteria. In Atlantic salmon (Salmo salar), N-Glycolylneuraminic sialic acid (Neu5Gc) concentration in skin mucus and skin mucous cell (MC) parameters such as size, abundance, and volumetric density were monitored during the transition from freshwater to seawater across five sampling dates. A significant positive regression was observed between Neu5Gc concentration (free Neu5Gc and total Neu5Gc, encompassing both free and bound forms) and MC parameters in four of the five sampling points, suggesting a relationship between mucous barrier characteristics and Neu5Gc concentration in the mucus. Moreover, the transition to seawater resulted in a significant decrease in both MC parameters and Neu5Gc concentration (p < 0.05). Together, these findings support the interpretation that MCs represent a source of Neu5Gc in the skin mucus and that both Neu5Gc levels and MC characteristics appear to change during the transition to seawater.
DOI: 10.29245/2578-3009/2026/1.1264 View / Download Pdf