Gill lamellar dilations (Telangiectasis) related to sampling techniques

Among fish killed by concussion (a blow to the head), lake trout Salvelinus namaycush readily developed telangiectasis, lamellar edema, and hemorrhagic thymi; Atlantic salmon Salmo salar and rainbow trout Salmo gairdneri developed thymic hemorrhages but few or no gill lesions. This illustrates a potentially overlooked bias that sampling techniques can cause in histologic analyses.