Parasites and hepatic lesions among pink salmon, Oncorhynchus gorbuscha (Walbaum), during early seawater residence.
J Fish Dis
; 35(2): 137-51, 2012 Feb.
Article
en En
| MEDLINE
| ID: mdl-22233513
Juvenile pink salmon, Oncorhynchus gorbuscha (Walbaum), in the Broughton Archipelago region of western Canada were surveyed over 2 years for sea lice (Lepeophtheirus salmonis and Caligus clemensi), gross and microscopic lesions and evidence of infections with viruses and bacteria. The 1071 fish examined had an approximate ocean residence time no longer than 3 months. A high prevalence of degenerative liver lesions, renal myxosporean parasites and a low prevalence of skin lesions and sea lice were observed. No indications of viral or bacterial diseases were detected in either year. The monthly prevalence of sea lice in 2007 (18-51%) was higher than in 2008 (1-26%), and the infestation density exceeded the lethal threshold in only two fish. Degenerative hepatic lesions and renal myxosporean parasites occurred in approximately 40% of the pink salmon examined in June of both years, and the peak monthly prevalence of hepatocellular hydropic degeneration was greater in 2007 (32%, in May) than in 2008 (12%, in June). Logistic regression analysis found skin lesions and hepatocellular hydropic degeneration significantly associated with sea lice. Most parasites and lesions occurred during both years, but the prevalence was often higher in 2007. Fish weight was 35% less in June 2007 than in June 2008, but condition factor was not different. Further research is required to monitor inter-annual variations and aetiology of the liver lesions and to assess their potential role on pink salmon survival.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Salmón
/
Agua de Mar
/
Copépodos
/
Infestaciones Ectoparasitarias
/
Enfermedades de los Peces
/
Hígado
Tipo de estudio:
Diagnostic_studies
/
Prevalence_studies
/
Risk_factors_studies
Límite:
Animals
País/Región como asunto:
America do norte
Idioma:
En
Revista:
J Fish Dis
Asunto de la revista:
BIOLOGIA
/
MEDICINA VETERINARIA
Año:
2012
Tipo del documento:
Article
País de afiliación:
Canadá
Pais de publicación:
Reino Unido