Neotropical helminthology | 2021
UNA NUEVA ESPECIE DE TRINIBACULUM (MONOGENEA: DACTYLOGYRIDAE) PARÁSITO DE LAS BRANQUIAS DE ASTYANAX FASCIATUS (CUVIER, 1819) (CHARACIFORMES: CHARACIDAE) EN UN RÍO NEOTROPICAL, ESTADO DE SÃO PAULO, BRASIL
Abstract
A new species of Monogenea - Trinibaculum pinctiarum n. sp. is described from the gills of Astyanax fasciatus known as lambari do rabo vermelho , sampled in the Paranapanema River, Jurumirim reservoir, Sao Paulo State, Brazil. The new species is allocated to the genus Trinibaculum because it has a double ventral bar and dextro-lateral vagina. It is the second species (first species is Trinibaculum altiparanae) belonging to this genus that parasitizes the gills of the fish genus Astyanax. This monogenean is similar to T. altiparanae regarding the haptor structures and the bulbous distal vagina. However, Trinibaculum pinctiarum n. sp. differs in having: (1) coiled male copulatory organ, (2) accessory structure shaped as tweezers, (3) absence of postmedian process in the ventral bar, and (4) hooks with depressed thumb. The phylogenetic hypothesis of the genus Trinibaculum (Consistency index = 87%, Retention index = 80%, length = 16) based on 13 transformation series is (Trinibaculum rotundus, T. brazilensis, T. altiparanae, T. pinctiarum n. sp.). Such hypothesis corroborates current phylogenies of characiformes fishes. Moreover, this study includes a new identification key for the species of the genus Trinibaculum based in morphological characters.