Description and comparative study of physico-chemical parameters of the teleost fish skin mucus

Article type: Research Article

Authors: Guardiola, Francisco A.^a | Cuartero, María^b | del Mar Collado-González, María^c | Arizcún, Marta^d | Díaz Baños, F. Guillermo^c | Meseguer, José^a | Cuesta, Alberto^{a; *} | Esteban, María A.^a

Affiliations: [a] Department of Cell Biology and Histology, Faculty of Biology, Campus Regional de Excelencia Internacional “Campus Mare Nostrum”, University of Murcia, Murcia, Spain | [b] Department of Analytical Chemistry, Faculty of Chemistry, Campus Regional de Excelencia Internacional “Campus Mare Nostrum”, University of Murcia, Murcia, Spain | [c] Department of Physical Chemistry, Faculty of Chemistry, Campus Regional de Excelencia Internacional “Campus Mare Nostrum”, University of Murcia, Murcia, Spain | [d] Centro Oceanográfico de Murcia, Instituto Español de Oceanografía (IEO), Murcia, Spain

Correspondence: [*] Corresponding author: Alberto Cuesta, Department of Cell Biology and Histology, Faculty of Biology, Campus Regional de Excelencia Internacional “Campus Mare Nostrum”, University of Murcia, 30100 Murcia, Spain. Tel.: +34 868884536; Fax: +34 868883963; E-mail: [email protected].

Abstract: The study of mucosal surfaces, and in particular the fish skin and its secreted mucus, has been of great interest recently among immunologists. Measurement of the viscosity and other physico-chemical parameters (protein concentration, pH, conductivity, redox potential, osmolality and density) of the skin mucus can help to understand its biological functions. We have used five marine species of teleost: gilthead seabream (Sparus aurata L.), European sea bass (Dicentrarchus labrax L.), shi drum (Umbrina cirrosa L.), common dentex (Dentex dentex L.) and dusky grouper (Epinephelus marginatus L.), all of them with commercial interest in the aquaculture of the Mediterranean area. Mucus showed a direct shear- and temperature-dependent viscosity, with a non-Newtonian behavior, which differed however between two groups: one with higher viscosity (D. labrax, U. cirrosa, D. dentex) and the other with lower viscosity (S. aurata, E. marginatus). In addition, there was a clear interrelation between density and osmolality, as well as between density and temperature. Taking into account that high values of viscosity should improve the barrier effect against pathogens but low values of viscosity are needed for good locomotion characteristics, our results may help elucidate the relationship between physico-chemical and biological parameters of skin mucus, and disease susceptibility.

Keywords: Fish, viscosity, protein concentration, density, osmolality, teleosts, skin mucus

DOI: 10.3233/BIR-15052

Journal: Biorheology, vol. 52, no. 4, pp. 247-256, 2015