Metazoan Parasites Infecting Xiphias gladius from the Eastern Coast of Algeria (SW Mediterranean Sea)

Five specimens of Xiphias gladius Linnaeus, 1758 were sampled from the eastern coast of Algeria and examined for their metazoan parasites. Pathological effects of the collected parasites were examined for the whole body of X. gladius. Four metazoan parasites species were collected: two monogeneans (Tristoma coccineum Cuvier, 1817; T. integrum Diesing, 1850), one copepod (Pennella instructa (Wilson, 1917)) and one parasitic nematode (Hysterothylacium aduncum (Rudolphi, 1802)). We report here for the first time a symbiotic species, Conchoderma virgatum Spengler, 1789 (Cirripedia) fixed on P. instructa. Collected monogenean and the copepod species are newly recorded for Algerian coast. Xiphias gladius is a new host for H. aduncum in the studied region. All examined specimens were infected (P = 100 %). The collected copepod parasite, P. instructa (P = 60 %) induces serious pathological effects to its host (necrosis and hemorrhage particularly). Histological sections showed that this copepod causes skin lesions, deteriorations on the dermal and muscle tissue.