Parasitic helminths of the non-native serrasalmid fish Metynnis lippincottianus from the Três Marias Reservoir, Southeast Brazil.

Maria De Fátima Cancella De Almeida-Berto,Cassandra Moraes Monteiro,Marilia De Carvalho Brasil-Sato

doi:10.1590/s1984-296120180040

Maria De Fátima Cancella De Almeida-Berto, Cassandra Moraes Monteiro + Show 1 more

Open Access

https://doi.org/10.1590/s1984-296120180040

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Abstract

Metynnis lippincottianus is a freshwater native fish to the Guiana basin and Amazon basin and was recently introduced into the São Francisco River in Brazil. This study aimed to determine the helminths parasites of M. lippincottianus from the Três Marias Reservoir, upper São Francisco River, State of Minas Gerais, Southeast Brazil. From 67 hosts examined, 63 were parasitized by 9,257 helminths represented by five species: Dadayius sp. [prevalence (P) = 1.49%, mean abundance (MA) = 0.01]; proteocephalid plerocercoids (P = 43.28%, MA = 5.04); Procamallanus (Spirocamallanus) inopinatus (P = 29.85%, MA = 0.54); Spinitectus rodolphiheringi (P = 2.99%, MA = 0.03); Spinoxyuris sp. (P = 85.07%, MA = 132.54). These findings show that M. lippincottianus is an additional host to the helminths infecting fish native to the São Francisco River (plerocercoids, P. (S.) inopinatus and S. rodolphiheringi), and highlight the fact that Dadayius sp. and Spinoxyuris sp., which were typically found in native Metynnis spp. in other basins, also parasitizing the non-native serrasalmid M. lippincottianus in São Francisco River. These two helminth species have thrived in this freshwater ecosystem with the expansion of the geographical distribution of the host species to the São Francisco River.

Highlights

The natural distribution of Metynnis lippincottianus (Cope, 1870), common name in Brazil: “pacu” or “pacu-marreca”, includes the Amazon River basin and the Guiana shield in the Northeast of the continent (FROESE & PAULY, 2017); it has expanded its geographic range to other South American watersheds (OTA et al, 2016)
The helminth fauna of M. lippincottianus was comprised of five taxa which included two species of Platyhelminthes: a juvenile specimen of Digenea, Dadayius sp., Cladorchiidae, (CHIOC 39001), and plerocercoid larvae of an unidentified species of Cestoda, Proteocephalidae (CHIOC 39002); and three species of Nematoda: Procamallanus (Spirocamallanus) inopinatus Travassos, Artigas & Pereira, 1928, Camallanidae (CHIOC 39004-male, 39003-female); Spinitectus rodolphiheringi Vaz & Pereira, 1934, Cystidicolidae (CHIOC 39005-female); and an unindentified species of the nematode genus Spinoxyuris Petter, 1994, Pharyngodonidae (CHIOC 39006a-male, 39006b-female)
A total of 9,257 parasite specimens were found in the 67 necropsied fish, among these 9,254 helminth specimens belonging to three species with a prevalence greater than 10% (Table 1) and with an aggregate pattern of distribution in v. 27, n. 3, july.-sept. 2018

Summary

Introduction

The natural distribution of Metynnis lippincottianus (Cope, 1870), common name in Brazil: “pacu” or “pacu-marreca”, includes the Amazon River basin and the Guiana shield in the Northeast of the continent (FROESE & PAULY, 2017); it has expanded its geographic range to other South American watersheds (OTA et al, 2016). Since 2004 M. lippincottianus has been fished at the Três Marias Reservoir, upper São Francisco River basin, State of Minas Gerais, Southeast Brazil (SATO & SAMPAIO, 2006; OTA et al, 2016) as well as in the middle (LUZ et al, 2009) and lower São Francisco River (ASSIS et al, 2017). There is no previous study on the helminth species that parasitize M. lippincottianus since it was introduced into the upper São Francisco River. In this sense, this paper aimed to determine which helminths parasitizing M. lippincottianus from the Três Marias Reservoir, upper São Francisco River, State of Minas Gerais, Southeast Brazil

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