Antimicrobial peptidesAntimicrobial peptides are increasingly recognized as a critical factor in host defence mechanism and found in organisms ranging from microbes, plants to animal species (Fernandes et al., 2004; Kennedy et al., 2009). It also plays an important role in fish when compared with mammals as fish rely more on their innate immune system (Hancock, 1997; Hancock and Scott, 2000). Fi..