Binds to bacterial LPS and may specifically inhibit the LPS-mediated activation of the hemolymph coagulation. It has a strong antibacterial effect especially on the growth of Gram-negative bacteria. Strong expression in hemocytes, heart and muscle, with weaker expression detected in gills and hepatopancreas. No expression detected in eyes. By injection with lipopolysaccharide. Expression is highest at 3 hours post-injection, decreases to basal levels at 12 hours post-injection and is up-regulated again at 24 hours post-injection. In the presence of recombinant ALF, the expression is significantly down-regulated at 3 hours and 6 hours post-injection.