title: Ultraviolet irradiation is an effective alternative to ozonation as a sea water treatment to prevent Kudoa neurophila (Myxozoa: Myxosporea) infection of striped trumpeter, Latris lineata (Forster).
abstract: Myxozoan parasites are known pathogens of cultured finfish. Kudoa neurophila n. comb. (Grossel, Dyková, Handlinger & Munday) has historically infected hatchery-produced striped trumpeter, Latris lineata (Forster in Bloch and Schneider), a candidate species for seacage aquaculture in Australia. We examined the efficacy of four water treatment methods to prevent K. neurophila infection in post-larval (paperfish) and juvenile striped trumpeter. Treatments included dose-controlled ultraviolet irradiation [hydro-optic disinfection (HOD)], ozone with conventional UV (ozone), mechanical filtration at 25 μm and then foam fractionation (primary filtration), and 50-μm-filtered sea water (control). In post-larvae (initially 10.3 ± 2.7 g, mean ± SD, 259 days post-hatching, dph), the infection prevalence (PCR test) after 51 days was 93 ± 12% in the control, 100 ± 0% in primary filtration and 0 ± 0% in both ozone and HOD. Likewise, in juveniles (initially 114 ± 18 g, 428 dph), prevalence was 100 ± 0% in the control and primary filtration treatments with no infection detected in ozone and HOD. Concurrently, there was a 50-100% reduction in heterotrophic bacteria and 100% reduction in presumptive Vibrio sp. in sea water HOD and ozone treatments. HOD with a dose of ≥44 mJ cm(-2) UV was as effective as ozonation at >700 mV ORP for 10 min, in preventing K. neurophila infection.
authors.affiliation: Fisheries Aquaculture and Coasts Centre, Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, Australia. jenny.cobcroft@utas.edu.au
authors.forename: J M
authors.initials: JM
authors.lastname: Cobcroft
authors.forename: S C
authors.initials: SC
authors.lastname: Battaglene
mesh_terms: D000818:Animals; D058491:Bacterial Load; D005393:Fish Diseases / Q000517:prevention & control*; D055764:Myxozoa / Q000528:radiation effects*; D010126:Ozone; D010273:Parasitic Diseases, Animal / Q000517:prevention & control*; D010473:Perciformes / Q000254:growth & development / Q000469:parasitology*; D012623:Seawater / Q000469:parasitology*; D014466:Ultraviolet Rays; D014733:Vibrio / Q000528:radiation effects; D014867:Water / Q000737:chemistry / Q000469:parasitology; D014871:Water Microbiology; D018508:Water Purification / Q000379:methods* / Q000592:standards
chemical_list: D014867:Water; D010126:Ozone