Mucus properties of Chinese carp and Indian carp: Physical barrier to pathogens

Abstract

The study was aimed to investigate the probable role of mucus in reception and/or repulsion of <em>Lernaea </em>in Indian and Chinese major carps. <em>Ctenophryngodon idella</em>, <em>Hypophthalmichthys moiltrix</em>, <em>Labeo rohita</em>, <em>Cirrhinus mrigala</em>, <em>Catla catla</em> and <em>Cyprinus carpio</em> averaging 830±316 g each were collected and disinfected with KMnO₄(8.0ppm) for collections of contamination free mucus. Total protein contents and size categorization were determined by Bradford Micro Assay and SDS-PAGE analysis. Lectin and alkaline phosphatase activities were also measured by hemagglutination (HA) titer and alkaline phosphatase test, respectively. Protein concentrations were the highest in <em>C. idella </em>and <em>C. catla </em>andthe lowest in <em>C. carpio</em>. Considering protein profiles mucus samples from <em>C. catla</em> contained the highest molecular weight proteins while <em>C. carpio</em> has one unique protein band of 14.13 kDa the weight of which resembles the weight of lysozyme, a protective element of mucus. Lectin activity was highest in <em>C. idella</em> indicative of low resistance while it was the lowest in <em>H. molitrix.</em> Alkaline phosphatase level was the highest in <em>C. catla</em>, and was the lowest in <em>C. carpio</em>. Overall results indicted <em>C. carpio </em>asthemost resistant species as it showed better values for the immune components. Higher values of protein contents and alkaline phosphatase for <em>C. catla</em> may be in favor of its higher susceptibility. These studies on mucus contents are good assessment indicators of the possibility of parasitic attacks in Chinese and Indian major carps.