Molecular characterization of a p38 mitogen-activated protein kinase gene from Scylla paramamosain and its expression profiles during pathogenic challenge

•The p38 MAPK from Scylla paramamosain was characterized by RACE-PCR, cloning, and sequencing and the phylogenetic status was verified.•Sp-p38 was widely present in various tissues of crab, with the highest expression in hemocytes and intestines.•The expression levels of Sp-p38 in hemocytes was significantly up-regulated after pathogen infection.