Eosinophilic granule cells in the gills of rainbow trout, Oncorhynchus mykiss: evidence of migration?

Rainbow trout, in groups of 3, were exposed to 109 cfu/ml Vibrio anguillarum in fresh or salt water, or were kept in non-infected fresh water. Gill filaments were removed from the fish and studied by light and electron microscopy. Eosoinophil granule cells were present throughout the tissue in association with capillary endothelia and freely within the capillary lumen in the 3 groups of fish. Injection with bacteria or exposure to salt did not exacerbate the presence of these cells in the lumen or lacunae. It is concluded that eosinophil granule cell migration occurs normally within the microcirculation of the gill..