Morpho-functional features of blood-forming organs and blood cells of stenodus leucichthys underyearlings

It is shown that mezonephros is a universal hemopoietic organ in which the formation of all cellular numbers: erithrocytes, granulocytes, agranulocytes takes place. A spleen is a central hemopoietic organ of the low vertebrates that contributes to the blood-forming process in young period of development. The gills of Stenodus leucichthys, being a boundary organ, along with respiratory and other functions performs also blood-forming function. The hematopoietic tissue is concentrated in the field of branchial arches at the basis of branchial petals. The contribution in hematopoiesis of gastrointestinal canal of white salmon underyearlings is rather small. In hemopoietic congestions there was an active development of leukocytes – lymphocytes and eozinofils. Thymus actively participates in limfocitopoes – there takes place a development of lymphocytes. Hassal’s corpuscles specify that thymus starts carrying out endocrine function.