Mariauxiella pimelodi n. g., n. sp. (Cestoda: Monticelliidae): a parasite of pimelodid siluroid fishes from South America

Mariauxiella pimelodi n. g., n. sp. (Cestoda, Monticelliidae, Othinoscolecinae) is described from the South American siluriform fishes Pimelodus ornatus and Pimelodus sp. caught in Brazil and Paraguay. When compared with other genera of South American monticelliids, the new genus exhibits the following morpho-anatomical characters: the particular development of the distal circular musculature of the suckers acting as a sphincter; the medullar ovary projecting numerous lobules into the dorsal cortex; and the uterus situated in the ventral cortex but with numerous outgrowths penetrating the medulla and reaching the dorsal cortex in pregravid proglottids. The new species is the fourth monticelliid cestode recorded from Pimelodus.