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Unilatus irae sp. nov. (Dactylogyridae) is described from the gills of the armored catfish, Leporacanthicus galaxias Isbrücker et Nijssen (Loricariidae: Ancistrinae), from Guamá river, Pará State, Brazil. The new species can be differentiated from its cogeneners by the combination of the following features: anterior anchor with well-developed superficial root, inconspicuous deep root, shaft bent at midpoint, forming angle of approximately 60°, evenly short curved point; posterior anchor with inconspicuous roots, sclerotized cap of base with small protuberance for articulation to posterior bar; evenly curved shaft and short point; anterior bar broadly V-shaped, with small posteromedial projection; and posterior bar anteriorly expanded on it midportion, with expanded ends slightly curved in posterior direction.
Three previously undescribed species of wageneri group of Gyrodactylus Nordmann, 1832 (subgenus Limnonephrotus, Gyrodactylidae, Monogenoidea) related to G. lavareti Malmberg, 1957 are described here. G. pomeraniae sp. nov. was found on roach (Rutilus rutilus) in Poland and Belgium, G. ouluensis sp. nov. on roach in Finland and G. salvelini sp. nov. on Arctic charr (Salvelinus alpinus) in the Lake Inari, Finland. A molecular redescription of G. lavareti on Coregonus lavaretus is also presented, and G. bliccensis on Alburnus alburnus from river Morava, Czech Republic is included in the phylogenetic analysis. In addition, a hybrid clone of maternal G. pomeraniae sp. nov. and paternal G. lavareti found on farmed rainbow trout (Oncorhynchus mykiss) is characterized. The molecular species description was based on the complete CO1 gene of the mitochondrial DNA, and on phylogenetic comparison of the internal transcribed spacer segment (ITS1-5.8S rDNA-ITS2) of nuclear ribosomal DNA. The species hosted by cyprinids were basal in the phylogeny rooted by numerous relatives of wageneri-species group.
Background. Asian pangasiids (Actinopterygii: Siluriformes: Pangasiidae), commonly referred to as “panga”, have recently became an important item on the European fish markets. The fish are currently imported from south-east Asia but the growing consumers’ demand is likely to motivate European fish growers to culture the “panga” locally. This in turn could bring about unforeseeable consequences for the aquatic environment. The presently reported study provides the first record of a pangasiid fish (two specimens) from the European natural waters. We attempted to identify the fish through complex morphometric procedures and to study all their parasites, thus determining their potential threat for the environment. Materials and Methods. Two specimens of pangasiid fish were captured in a pond, in the city of Szczecin, Poland. The fish were examined following procedures commonly accepted in morphological studies yielding detailed measurements. The key structures were described and illustrated (e.g., the shape of dentition on both the vomerine and palatine plates). The measurements were taken with an electronic calliper and a dissecting microscope (Nikon SMZ 1000), coupled with the Lucia Measurement System. Additionally, during necropsy, selected organs were checked for the presence of parasites. Results. One of the fish specimens hosted the monogenoid parasite, Thaparocleidus caecus, that has never been found in Europe. Metric and meristic characters of fish studied, as well as the presence of monogenoid T. caecus suggest that the fish found were representatives of Pangasianodon hypophthalmus, however, some features, especially those related to the ratio between fins and body or total length, differ markedly from the species description. Comparative analysis suggested that the two specimens collected in Szczecin are hybrids, most likely of P. hypophthalmus with other species, of unknown origin, presumably imported from Thailand. Conclusion. The specific identity of pangasiids imported alive to Europe should be monitored in the future. Additional genetic studies are needed. The monogenoid parasite found on the fish studied poses no threat to the native ichthyofauna (because of its very narrow host-specificity).
A new species of Rhinonastes, hitherto monotypic, is described and illustrated from the nasal cavity of ‘curimat’, Prochilodus argenteus from São Francisco River, Brazil. Rhinonastes curimatae n. sp. presents a male copulatory organ with more than five rings while the type species of the genus is characterized by male copulatory organ with less than two rings. This is the first record of a nasal parasite in P. argenteus.
Mymarothecium viatorum sp. n. (Dactylogyridae, Ancyrocephalinae) is described from the gills of Piaractus brachypomus (Teleostei, Serrasalmidae) captured in the warm water canal of a power plant of the city of Szczecin, Poland. The new species is differentiated from other species in the genus by presenting a copulatory ligament that articulates to the accessory piece subterminally (not terminally), posteromedial projection on the ventral and dorsal bars; further, superficial root of the dorsal anchor that bends and articulates to the dorsal bar and vagina slightly sclerotized. This is apparently the first species of an introduced Neotropical Monogenoidea collected from the environs of Central Europe.
Background. Monogenean parasites Pseudodactylogyrus anguillae and P.bini were for the first time recorded on eel in 1995. The aim of the present study was to determine their distribution in Poland and to verify their measurements against literature data. Materials and Methods. A total of 201 young eels ascending rivers of Polish Western Pomerania, emptying to the Baltic Sea, were collected and necropsied using commonly used methods. Results. Altogether, 574 monogeneans were found on the gills of the eels studied, of which P. anguillae constituted 82%. Measurements of hard elements of the two species of parasites were similar to those already described from Poland. Conclusion. The present paper constitutes a new record of Pseudodactylogyrus anguillae and P. bini, supported by measurements.
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