Depletion of head kidney neutrophils and cells with basophilic granules during peritoneal inflammation in the goldfish, Carassius auratus

The head kidney morphology of the goldfish with the experimental peritoneal inflammation (on day 2 after i.p. injection with sterile 3% Thioglycollate ) is compared with that in the control fish (i.e. on day 2 after i.p. injec tion with a strile physiological saline PBS) with special emphasis on ident ification of granulocytes on semithin and consecutive ultrathin sections. T he most striking feature of head kidneys of goldfish in the course of perit oneal inflammation is a severe depiction of mature neutrophils and cells wi th basophilic granules (basophils/mast cells). These observations suggest t he involvement of the head kidney, the main hematopoietic organ of teleosts , in the inflammatory process.