A new species of Tereancistrum (Monogenea: Dactylogyridae), parasite of Prochilodus lineatus (Characiformes: Prochilodontidae) from southeast Brazil

Lucas Aparecido Rosa Leite,Vanessa Doro Abdallah,Larissa Sbeghen Pelegrini,Rodney Kozlowiski De Azevedo

doi:10.1590/s1984-29612020024

Abstract

A new species of Tereancistrum Kritsky, Thatcher & Kayton, 1980 collected of Prochilodus lineatus gills from the Batalha River, Tietê-Batalha basin, São Paulo State, Brazil is described. The new species can be distinguished from its congeners mainly by the configuration of the ventral bar, which has an anvil-shaped characteristic with corrugated anterior projection. Tereancistrum takemotoi n. sp. is morphologically similar to T. toksonum Lizama, Takemoto & Pavanelli, 2004 in terms of their dorsal bars (Y-shaped), their dorsal anchors with divergent roots (superficial and deep) wherein their deep root rather elongated, and by the fact that they both have the male copulatory organ counterclockwise. However, only T. takemotoi n. sp. presents the male copulatory organ with 2¼ rings and shows undulations in the anterior margin of the dorsal bar. These undulations are absent in T. toksonum (which only has 1¼ rings). This is the fourth Tereancistrum species described for P. lineatus and the first described for the region from the Tietê-Batalha basin.

Highlights

Prochilodus lineatus Valenciennes, 1837, known in Brazil as curimba, curimbatá, or curimatã, is one of the most abundant native fish species in the floodplains of the upper Paraná River, it is distributed across the country
Fifty specimens of P. lineatus were collected at two sites on the Batalha River, part of the Tietê-Batalha basin, in São Paulo State, Brazil
The new species is assigned to Tereancistrum genus due to the presence of distinctly spatulate accessory sclerites articulated to the tip of the superficial root of the ventral anchors, its two pairs of eyes, its overlapping gonads, and similar hooks (Kritsky et al, 1980; Kritsky & Boeger, 1989)

Summary

Introduction

Prochilodus lineatus Valenciennes, 1837, known in Brazil as curimba, curimbatá, or curimatã, is one of the most abundant native fish species in the floodplains of the upper Paraná River, it is distributed across the country. It has substantial commercial appeal and is considered a medium to large species that engages in extensive migrations for food and reproduction (Agostinho et al, 1997). The species of the family Dactylogyridae Bychowsky, 1933 are the most know gill parasites in the Neotropical region and are generally not highly pathogenic (Boeger & Vianna, 2006). This family of parasites includes Tereancistrum Kritsky, Thatcher & Kayton, 1980 whose main morphological characteristic is the presence of sclerites associated with ventral anchors (Kritsky et al, 1980)

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