STE-137 was initiated in 1963 from pooled steelhead embryos (Oncorynchus mykiss). This heteroploid cell line, also known as steelhead embryo-137, replicates and detects common salmonid viruses (infectious pancreatic necrotic virus (IPNV), infectious hematopoietic necrosis virus (IHNV) and viral hemorrhagic septicaemia virus (VHSV)). The growth temperature ranges from 15-21�C with a routine propagation at 18�C.