Pathological effects of Peroderma cylindricum (Copepoda: Pennellidae) on the kidneys of its pilchard host, Sardina pilchardus (Osteichthyes: Clupeidae), from Tunisian coasts

Abstract

Peroderma cylindricum (Heller, 1865) is a pennellid copepod, common on the pilchard Sardina pilchardus (Walbaum, 1792), from the Tunisian coasts. The cephalic area of the parasite displays an important network of cephalic rootlets with dichotomic ramifications inserted mainly into the anterior part of the host's kidney. A histological study shows that these formations alter the kidney's structure. This is confirmed by the destruction of excretory structures sometimes leading to the appearance of haematoma. The possible role of these cephalic rootlets is compared with their role in other parasitic crustaceans displaying the same formations. It is probable that the presence of this parasite induces mortality in pilchards, mainly 1 to 2 yr old.