The ontogeny of cellular immunity in the rainbow trout, Salmogairdneri Richardson, in relation to the stage of development of the lymphoid organs

Abstract
Rainbow trout fry become immunocompetent with respect to the allograft response as early as 14 days post-hatch (at 140C). The ability to respond to foreign tissue grafts is correlated with the presence of a morphologically mature lymphoid population in the thymus and the kidney, and the presence of circulating lymphocytes.