Experimental infection of rainbow trout, Oncorhynchus mykiss (Walbaum), juveniles with Loma salmonae at a water temperature of 15 °C yielded detectable parasite DNA within the gills by week 2 post‐exposure (PE) and detectable spore‐wall antigen within developing xenomas by week 3 PE, as determined by in situ hybridization and monoclonal antibody (Mab) based immunohistochemistry, respectively. The microsporidian was most commonly located within endothelial cells of lamellar basal channels. Whereas the onset of xenoma formation appeared to be relatively synchronous, as expected from previous studies, xenoma dissolution followed an unexpected biphasic pattern with peaks at weeks 4 and 9 PE. The onset of significant growth rate suppression, at week 4 PE in exposed fish, was temporally associated with the appearance of gill lesions which, in turn, were centred about sites of premature xenoma dissolution. The latter was determined by the detection of spore‐wall antigen within lesions. Co‐habitant control fish began developing xenomas by week 10, indicating the infective potential of those spores released from the principal fish during early xenoma dissolution. Although infection with L. salmonae significantly affects fish growth rates, the time‐course of this suppression is limited, and as an unexpected finding, growth rate recovery commences prior to the infection’s resolution.

The ability of a parasite to transmit from one fish to another is important in the dissemination of disease. Groups of 25 naive rainbow trout (RBT), Oncorhynchus mykiss (Walbaum), were exposed to Loma salmonae by feeding on the viscera (gills, hearts and spleens) from L. salmonae‐infected donor RBT (DRBT) or by cohabitation with infected DRBT. Exposure occurred 3, 7, 11 and 15 weeks after the DRBT were infected. All naive RBT were examined 7 weeks post‐exposure (PE) to the DRBT. Naive RBT, exposed to DRBT at week 3 PE, by feeding on viscera or by cohabitation, failed to develop visible branchial xenomas. Cohabiting naive RBT with DRBT, at week 7 PE and week 11 PE, resulted in the development of branchial xenomas. Xenomas failed to develop in naive RBT exposed via cohabitation to week 15 PE DRBT. Naive RBT, exposed by feeding on the viscera of DRBT at week 7 PE, week 11 PE and week 15 PE, developed branchial xenomas. The transmission potential of viscera from L. salmonae‐infected DRBT at week 15 and week 20 PE was also examined. Naive RBT, fed with viscera free of visible branchial xenomas, from DRBT at week 15 PE and week 20 PE, developed branchial xenomas by week 7 PE. A polymerase chain reaction (PCR) was used to detect L. salmonae DNA from the water and sediments of a tank of L. salmonae‐infected RBT at week 7 PE. The method and timing of exposure of naive fish to L. salmonae‐infected fish are important in disease transmission and may be useful in predicting and preventing disease outbreaks in aquaculture.

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Purpose Following a competitive bid, Sheffield Hallam University were successful in developing and delivering a Corporate Business and Management Degree, for Nestlé UK and Ireland. The purpose of this paper is to present a case study of how the degree programme has evolved and been developed into an apprenticeship, the challenges faced and the partnership approach taken to overcome them. It will also explore the impact on the apprentices, Nestlé and Sheffield Hallam University. Design/methodology/approach Information presented in the paper is drawn from the organisations own work in developing a degree apprenticeship programme. It builds on information from the original project brief and the bid, as well as on-going evaluation of how the programme is progressing. Findings Responding to talent gaps in the general management population the development of a level 6 Chartered Manager Degree Apprenticeship provides progression for future managers of Nestlé, offering a fast-track route into a career in business and management. The evolution of this higher degree apprenticeship scheme and potential benefits are brought to life in this case study. Originality/value The paper is based on the authors own experience and employer consultation.

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Routine and post-exercise metabolic rates were measured for juvenile rainbow trout Oncorhynchus mykiss and brook trout Salvelinus fontinalis infected with the microsporidium gill parasite Loma salmonae under laboratory conditions. Rainbow trout increased routine and postexercise metabolic rate in response to infection compared with controls. Brook trout, on the other hand, lowered routine metabolic rate without effecting post-exercise metabolic rate compared to controls. The result of these 2 different strategies may either reflect defense of metabolic scope or a difference in the rate of recovery of the excess post-exercise oxygen consumption between the 2 species in response to the same infection. KEY WORDS: Loma salmonae · Metabolic rate · Microsporidian · Oxygen consumption · Salmonid Resale or republication not permitted without written consent of the publisherDis Aquat Org 67: [233][234][235][236][237] 2005 Prince Edward Island, and acclimated at 15°C for several months in the aquarium facility of the Atlantic Veterinary College, in Charlottetown.A total of 150 fishes were distributed between 3 flow-through tanks, and individuals in 2 of the tanks were infected with 2 × 10 6 Loma salmonae spores by feeding with infected gill tissue. The third tank contained uninfected fishes (control). The L. salmonae spores fed to the fishes had been isolated previously from infected rainbow trout or brook trout. The brook trout Salvelinus-variant of L. salmonae was derived from that described by Sanchez et al. (2001b), whereby the sequential pathology is the same as that for the Oncorhynchus-variant used in rainbow trout. This standard method of infection challenge with L. salmonae results in 100% of the fishes becoming infected within 6 wk (Speare et al. 1998). Water in all tanks was maintained at 15°C and 95% air-saturation. The fishes were fed daily (equivalent of 2% of their body weight) on a commercial extruded-pellet diet (HiPro 3.0 GR, Corey Feed Mills).After 4 wk post-inoculation, the fishes were starved for 24 h prior to being randomly selected and placed for 24 h into individual, black, acrylic respirometer chambers (internal volume approximately 1 l) supplied with the same flow-through freshwater as that supplying the tanks. Food was withheld from fish whilst they were in the respirometer chambers. A total of 9 rainbow trout and 8 brook trout were tested from each treatment (infected or uninfected controls). Control and infected individuals of each species were tested on the same day.To determine oxygen uptake, the water flow to each chamber was stopped and the chamber sealed. A 1 ml water sample was removed and injected into a thermostatically controlled oxygen electrode (1302 electrode, Strathkelvin instruments) calibrated against a 2% NaSO 3 solution (zero) and air-saturated freshwater (~158 mm Hg). The electrode was connected to a Strathkelvin Instruments model 782 O 2 meter. A second water sample was removed after 15 min and remeasured, after which the water flow was restored to the respirome...

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.

The objectives of the study were (1) to determine an acceptable dose of dietary monensin against microsporidial gill disease (MGD) of salmon caused by Loma salmonae and (2) to determine the life stage of