Molecular characterization and expression analysis of a novel cystatin-like gene in a hypoxia-tolerant Indian catfish, Clarias batrachus [Linnaeus, 1758]

► A novel member CbCystatin was identified from Clarias batrachus. ► CbCystatin had putative cystatin/monelin like domain. ► It might be a transmembrane and/or intermediate protein in signaling pathways. ► CbCystatin was found to be clustered into family 2 cystatins. ► Its expression was up-regulated in response to short and long periods of hypoxia.