First documented case of ectoparasitism in electric eel: Dolops discoidalis (Branchiura: Argulidae) infesting Electrophorus voltai (Teleostei: Gymnotidae).

Electrophorus voltai, commonly known as poraquê, is a fish species widely distributed in the Amazon Basin. This study presents the first record of parasitism by Dolops discoidalis, an obligate hematophagous ectoparasite, in E. voltai from the Xingu River Basin. Six host specimens were examined (mean total length: 119.5 cm), harboring 41 parasite individuals (19 males and 21 females), with a prevalence of 100 % and a mean intensity of 6.83 ± 2.22. Parasites were attached to specific regions of the host's body. Our findings support the affinity of D. discoidalis for scaleless fish and contribute to the still limited knowledge of the parasitic fauna of poraquê, Electrophorus species.