Relationships of Parasitic Isopods Lironeca ovalis and Olencira praegustator to Marine Fish Hosts in Delaware Bay

Abstract

Abstract The isopods Lironeca ovalis and Olencira praegustator infest the gill and buccal cavities of at least seven species of fishes taken in the lower Delaware River Estuary. The free-swimming male stages of these two species are external facultative parasites, apparently feeding on lipid substances of the many fishes which serve as intermediate hosts. Both male and female stages of L. ovalis were most prevalent on bluefish, Pomatomus saltatrix, which served as both an intermediate and terminal host. Female L. ovalis showed the highest incidence of infestation among bluefish, 19.1%; silver perch, Bairdiella chrysura, 6.1%; white perch, Morone americana, 4.1%; weakfish, Cynoscion regalis, 2.8%; and striped bass, Morone saxatilis, 1.5%. Female O. praegustator were found only in 0.8% of the 590 Atlantic menhaden, Brevoortia tyrannus, observed.