The parasitic isopod, Lironeca raynaudii (Isopoda, Cymothoidae) of the sand-flounder, Rhombosolea plebeia, in Wellington Harbour

Abstract

Six pre-embryonic and five post-embryonic stages of development of Lironeca raynaudii (Isopoda, Cymothoidae) are described. The parasitic isopod is a protandric hermaphrodite. Its development to the female stage may be delayed by the presence of another female. It is found to be host and site specific. Infestation rate varies with season and increased with the length (age) of the fish host, Rhombosolea plebeia. It shows no preference for either sex of the host. It feeds mainly on the blood and inflicts considerable damage to the gill filaments of the fish host. The moulting process, fecundity and course of infection of the parasitic isopod are also considered in the text.