a1 Kingston University, School of Life Sciences, Kingston, Surrey, KT1 2EE.
a2 Department of Zoology, The Natural History Museum, Cromwell Road, London, SW7 5BD
Presumptive viral erythrocytic necrosis (VEN) was recorded from 1/4 of the benthopelagic fish Coryphaenoides (Nematonurus) armatus (Teleostei: Macrouridae) trawled from the abyss west of Portugal. In a blood smear made from the caudal vein of this fish, 8·6% of erythrocytes contained 1–2 intracytoplasmic inclusions which were invariably round and 1·13 ±0·43 μm in diameter. An eosinophilic granular area accompanied many inclusions. In comparison with erythrocytes from uninfected specimens of C. (N.) armatus, most of those from the infected fish were larger. Erythrocytes with suspected VEN exhibited either normal staining, or were pale, with swollen or crenated nuclei which were often displaced to the cell periphery. Erythrocyte ghosts, with and without inclusions and granules, were present in the same infected fish, suggesting osmotic damage to red cells resulting from the infection. None of 13 other C. (N.) armatus and 27 fish examined from collections made south of Maderia, representing another 20 species of benthic, benthopelagic and mid-water fish, had detectable infections.