Common grilled fish include mackerel, hairtail, croaker and Pacific herring. Largehead hairtail is a major commercial species. Ships from the harbor often travel to Heuksando to fish for skate and hairtail. Anthene opalina, the opal hairtail, is a butterfly in the family Lycaenidae. May. The festival of Largehead Hairtail () takes place around Yeongsan Lake every October. The largehead hairtail is also notable for being fairly easy to debone. Anthene arnoldi, or Arnold's hairtail, is a butterfly in the family Lycaenidae. The largehead hairtail ("Trichiurus lepturus") or beltfish is a member of the cutlassfish family, Trichiuridae. Its diet consists mostly of fish; it particularly likes the Atlantic bigeye and largehead hairtail.