Diversity of Monogenoidea parasitizing scombrid fishes from Rio de Janeiro coast, Brazil

Eleven known species of Monogenoidea were found parasitizing six different species of scombrid fishes collected from Rio de Janeiro coast, Southwestern Atlantic Ocean: Capsala biparasitica , Capsala katsuwoni ,  Capsala notosinense ,  Nasicola brasiliensis ,  Nasicola klawei ,  Allopseudaxinoides euthynni , Sibitrema poonui ,  Hexostoma albsmithi , Hexostoma euthynni , Hexostoma keokeo  and Hexostoma sibi . Katsuwonus pelamis  is reported as a new host to A. euthynni  and Thunnus obesus  to H. albsmithi . Capsala notosinense, A. euthynni, H. albsmithi and  H. sibi  are referred for the first time in Brazil, Southwestern Atlantic Ocean. Morphological and morphometric features are presented for each species.