ISSN:
1365-2761
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
,
Medicine
Notes:
Loma salmonae is an important microsporidian pathogen affecting the mariculture of Pacific salmon, Oncorhynchus tshawytscha (Walbaum). Clinical signs associated with infection arise when the parasite enters sporogony and forms xenoparasitic complexes (xenomas) within the gill. The present study tested a thermal unit (TU) model, which was devised to predict the timing of xenoma formation, under conditions in which water temperature changed during the course of infection. In vivo trials with juvenile trout showed that the model [TU for xenoma onset = (days post exposure) × ( °C above 7 °C)] accurately predicted the onset time for xenomas when fish were moved from either 11 or 5 °C to 15 °C at various intervals after exposure. These findings suggest that the TU model may allow aquaculturists to predict disease onset. However, the model failed when fish were moved from 15 to 5 °C at intervals after exposure. This finding suggests that the temperature-constrained phase of the life-cycle of L. salmonae occurs early on after the spore is ingested by the fish.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1046/j.1365-2761.1999.00180.x
