New records of crustaceans infesting Phractocephalus hemioliopterus (Siluriformes: Pimelodidae), the large catfish from the Amazon

Abstract

The aim of the present study was to investigate the infracommunities of ectoparasitic crustaceans in Phractocephalus hemioliopterus Bloch and Schneider, 1801, a catfish from the lower Amazon River, in the state of Pará, eastern Amazon region, Brazil. From 12 hosts examined, a total of 45 specimens of crustacean ectoparasites from 5 species were found in the tegument, oral cavity or dorsal fins. The species were: Argulus multicolor, Argulus violaceus, Dolops nana, Dolops discoidalis, and Braga patagonica. Dolops discoidalis was the dominant ectoparasite, while D. nana had the highest mean intensity in the tegument, which was the most infested host site. This is the first record of A. multicolor, A. violaceus, D. nana and B. patagonica parasiting P. hemioliopterus.