Lobatozoum woodi n. sp. (Digenea: Didymozoidae) parasitizing Euthynnus alletteratus (Scombriformes: Scombridae) in the coast of the State of Rio de Janeiro, Brazil.

The aim of this study was to describe a new species of Didymozoidae (Trematoda) found in the mesentery of Euthynnus alletteratus (Rafinesque) off Cabo Frio, in the coastal area of the state of Rio de Janeiro, Brazil. Thirty specimens of E. alletteratus were obtained between August 2023 and June 2024, directly from traders who sell fresh fish in markets.

New and previously described species of Ameloblastella (Monogenoidea: Dactylogyridae) parasitizing Hypophthalmus marginatus and Pimelodina flavipinnis (Siluriformes: Pimelodidae) from the Tocantins River, Maranhão State, Brazil.

A new and two previously described species of Ameloblastella Kritsky, Mendoza-Franco & Scholz, 2000 were found in the gills of two pimelodid catfishes from the Tocantins River, Maranhão State, Brazil: Ameloblastella prima n. sp. from Pimelodina flavipinnis Steindachner, and A.

Dactylogyrids (Platyhelminthes, Monogenea) from the gill lamellae of doradids (Siluriformes) with description of five new species of Cosmetocleithrum and new geographical distribution for known species from the Neotropical Region, Brazil.

Five new species of Cosmetocleithrum were described parasitizing the gill filaments of neotropical doradid fishes. Cosmetocleithrum undulatum n. sp.

Two new species of (Monogenoidea, Dactylogyridae) parasitizing (Characiformes, Curimatidae) and a new record for in the Tocantins River, Maranhão, Brazil.

Several studies have demonstrated parasitism by monogenoids in characiform fish in the Neotropics. During studies on the helminth fauna of curimatids from the Tocantins River, specimens of Eigenmann & Eigenmann, 1889 were examined and species of Hanek, Molnar & Fernando, 1974 were found. Species of the genus are characterized mainly by the complex shape of haptoral anchors with a modified dorsal anchor, composed by two subunits, dorsal-median and dorsal.