The life cycle of tetraphyllid cestodes is complex, involving plerocercoid larvae that can utilize teleost fish as a second intermediate host or paratenic host, in which they can exhibit a diversity of plerocercoid larvae. The objective of this study is the morphological characterization of tetraphyllid plerocercoids in Trichiurus lepturus Linnaeus, 1758 from the coast of the state of Rio de Janeiro, Brazil. In July 2018, 33 specimens of T. lepturus were obtained from professional fishermen, captured near the Cagarras archipelago (23°1'52"S, 43°11'56"W), state of Rio de Janeiro, Brazil. The hosts were weighed, measured, and subjected to necropsies under a stereoscopic microscope for the collection of plerocercoids. The collected specimens were fixed and prepared following traditional helminthological techniques. Morphological and morphometric studies of the parasites were conducted, co...

The aim of this study was to register for the first time parasitism by Hepatozoon (Miller, 1908) in two species of bufonid anurans in areas of the Caatinga in Brazil, and to present morphometric analysis on the parasites and parasitized erythrocytes. During helminthological studies on anurans from the Brazilian Caatinga in 2019, blood smears of three specimens Rhinella diptycha (Cope, 1862) and three of Rhinella granulosa (Spix, 1824) in the municipality of Petrolina, state of Pernambuco, Brazil were analyzed. To make blood smears, blood samples were collected intracardiacally or through puncturing the ventral abdominal vein. The smears were analyzed under a light microscope at 1000x magnification. Morphometric dimensions of host cells and parasites were measured. The only parasite forms encountered in the blood of the two anuran species were intraerythrocytic gametocytes of Hepatozoon s...