Sea lice (Copepoda: Caligidae), a Serious Pest of Farmed Fishes in Korea

Abstract

Sea lice (Copepoda, Caligidae) especially Lepeophtheirus spp. and Caligus spp. are considered as pests of cultured fish, causing serious diseases and economic losses in fish aquaculture worldwide. At Tongyeong marine living resources research & conservation center (TMRC), KIOST, the sea ranched marine fishes have recently been screened for the infection of parasites. Two commercially important hosts such as red seabream Pagrus major and Korean rockfish Sebastes schlegelii were surveyed for the period of one year. Here, we report the infection of sea lice, effects, ecology and its possible life cycle. 1) Caligus sclerotinosus Roubal, Armitage & Rohde, 1983 was found infected on the body surface of P. major (Sparidae). Prevalence was 100%, mean intensity 7.06, maximum intensity 49, and minimum intensity 2. Adult females, males and few chalimi were observed and identified by their morphology. As an average of all our collections, less than 0.6% of individuals were chalimi. We suggest, therefore, that adults of C. sclerotinosus undergo ontogenetic host switching after their final moult. 2) Lepeophtheirus elegans Gusev, 1951 was found infected on the body surface and fins of S. schlegelii (Sebastidae). Prevalence was 98.8%, mean intensity 6.45 and maximum intensity 29. Some hosts were found with lesions and severe infection of L. elegans and C. sclerotinosus may cause secondary infection on itssearch & conservation center (TMRC), KIOST, the sea ranched marine fishes have recently been screened for the infection of parasites. Two commercially important hosts such as red seabream Pagrus major and Korean rockfish Sebastes schlegelii were surveyed for the period of one year. Here, we report the infection of sea lice, effects, ecology and its possible life cycle. 1) Caligus sclerotinosus Roubal, Armitage & Rohde, 1983 was found infected on the body surface of P. major (Sparidae). Prevalence was 100%, mean intensity 7.06, maximum intensi