Viruses were the least represented among pathogens. The Baculoviridae family was the most predominant with 21 matches, but the corresponding sequences were inhibitors of apoptosis (IAPs) [81] that could also be part of the clam's transcriptome. Five viral families were found in our transcriptome study: Iridoviridae, Herpesviridae, Malacoherpesviridae, Picornaviridae and Retroviridae. A well-known bivalve pathogen was also identified, the ostreid herpesvirus 1, which has been previously been found to infect clams [82] .