The hystopatology developing in the sand smelt Atherina boyeri Risso 1810 from Northern Italy as the result of a natural infection by Telosentis exiguus Von Linstow 1901 (Achanthocephala) was studied and desribed. Microscope examination of sections of intestinal tissue showed that the parasites did not penetrate through all intestinal layer, and that damage was mostly limited to the epitheliu
