White spot syndrome virus (WSSV) is a double-stranded DNA virus that is pathogenic to cultured shrimps. Although there have been few reports on free-living WSSV relatives, some shrimp and crabs have been shown to harbor endogenous WSSV-like sequences. To obtain resources for studying comparative genomics of WSSV and its relatives, we explored 15 crustacean genomes for endogenous WSSV-like sequences.