THE DISCOLORATION OF HALIBUT

The greenish-yellow discoloration of the ventral side of Hippoglossus hippoglossus (Linn.) is described. This discoloration is often accompanied by softness of the flesh, which greatly reduces the value of the fish. The color-producing organism was isolated and identified as Pseudomonas fluorescens; its characteristics are given. Examination of materials from which the halibut might be infected revealed that the ultimate source of the organism was the fresh-water ice in which the fish were packed after being caught. Some sixteen other organisms, isolated from freshly caught living halibut and from sea water, are fully described.