Ichthyouris voltagrandensis n.sp. (Nematoda: Pharyngodonidae) from Myleus tiete Eigenmann & Norris, 1900 (Osteichthyes: Characidae) in the Volta Grande Reservoir, MG, Brazil

Abstract

The present work studied helminth parasites of "pacu-manteiga", Myleus tiete (Osteichthyes: Characidae) from Volta Grande Reservoir, MG, Brazil. Fishes with 142.6 ± 24.7 g weight and 17.3 ± 1.0 cm total length were collected. Five out six analysed fish (prevalence 83.3%) were parasitized in the intestine with an average of 535.6 ± 334.6 oxyurid nematodes per fish. The helminth was identified as Ichthyouris voltagrandensis n.sp. (Nematoda: Pharyngodonidae). It differs from I. brasiliensis (Moravec et al., 1992a) by the absence of lateral alae, higher measures of tail and caudal alae of males, esophageal isthmus length, distance of excretory pore from anterior end and spicule length. In addition, eggs were provided by two long filaments in just one pole and by the first time the authors observed flagellate spermatozoa from dissected males. The authors exposes comparative table of measures of the five described species of the genus Ichthyouris.

Redescription of Ichthyouris bursata Moravec & Prouza, 1995 (Nematoda: Pharyngodonidae), a parasite of wild and aquarium-reared discus Symphysodon spp. (Osteichthyes)

“…However, the present SEM study, used for the first time for the male, shows that the ''small ventral postanal papillae'' reported by Moravec & Prouza (1995) were, in fact, sclerotised plate-like structures on the posterior cloacal lip. Similar cloacal plate-like structures were also reported for I. ovifilamentosa Moravec & Thatcher, 2001, I. ro Inglis, 1962and I. voltagrandensis Martins, Yoshitoshi & Umekita, 2001(see Inglis, 1962Martins et al, 2001;Moravec & Thatcher, 2001). The digital phasmids, the median cone-shaped outgrowth on the posterior cloacal lip and short 'hairs' on the cloacal lips were overlooked by Moravec & Prouza (1995) using the light microscope; this was confirmed by a reexamination of the type-specimens of I. bursata (Fig.…”

“…At present, a total of six species of Ichthyouris are known to parasitise South American freshwater fishes: I. brasiliensis Moravec, Kohn & Fernandes, 1992 2001 (Inglis, 1962;Moravec et al, 1992a,b;Moravec & Prouza, 1995;Martins et al, 2001;Moravec & Thatcher, 2001). Of these, I. brasiliensis, I. laterifilamenta and I. voltagrandensis are parasites of catfishes (Doradidae, Loricariidae) or characiforms (Characidae) and can be easily distinguished morphologically from I. bursata (see Moravec, 1998;Martins et al, 2001).…”

“…Of these, I. brasiliensis, I. laterifilamenta and I. voltagrandensis are parasites of catfishes (Doradidae, Loricariidae) or characiforms (Characidae) and can be easily distinguished morphologically from I. bursata (see Moravec, 1998;Martins et al, 2001). All of the remaining congeneric species are parasitic in fishes of the family Cichlidae.…”

“…, I. bursataMoravec & Prouza, 1995, I. laterifilamenta Moravec, Kohn & Fernandes, 1992, I. ovifilamentosaMoravec & Thatcher, 2001, I. ro Inglis, 1962 and I. voltagrandensis Martins, Yoshitoshi &Umekita, …”

A New Species of Ichthyouris Inglis, 1968 (Nematoda: Pharyngodonidae) Parasitizing Two Characiform Fishes from Tocantins River, Maranhão State, Brazil

“…Four species have been described from Brazil: Ichthyouris brasiliensis Moravec, Kohn, and Fernandes, 1992 from Megalancistrus aculeatus (Perugia) (Loricariidae); Ichthyouris laterifilamenta Moravec, Kohn, and Fernandes, 1992 from Trachydoras paraguayensis (Eigenmann & Ward) (Doradidae); Ichthyouris ovifilamentosa Moravec and Thatcher, 2001 from Cichlasoma sp. (Cichlidae); and Ichthyouris voltagrandensis Martins, Yoshitoshi and Umekita, 2001 from Myleus tiete Eigenmann & Norris (Characidae) (Moravec et al 1992a, b;Martins et al, 2001;Moravec and Thatcher, 2001). Recently, Cárdenas et al (2018) reported I. ro and Ichthyouris bursata Prouza, 1995 collected from Mesonauta festivus (Heckel, 1840) in the central Brazilian Amazon region, representing the first report of these species in Brazil.…”