No abstract

Diversity of Creptotrema was investigated using morphological and molecular tools, including data for Creptotrema creptotrema (type-species). Three new species, parasites of Brazilian fishes, are described: Creptotrema conconae n. sp. (type-host, Imparfinis mirini Haseman), Creptotrema schubarti n. sp. (type-host, Characidium schubarti Travassos) and Creptotrema megacetabularis n. sp. (type-host, Auchenipterus osteomystax (Miranda Ribeiro)). The diagnosis of the genus was amended to include new features. The new species differ from each other mainly in terms of body shape, relative sucker size, and testes position. DNA sequences were obtained from Creptotrema spp. from Brazil, including 28S, ITS and COI. Genetic divergences among the new species and C. creptotrema varied from 2.1 to 5.2% (21–49 bp) for 28S, and 6.6 to 16.4% (21–45 bp) for COI. Phylogenetic analysis (28S) placed the newly generated DNA sequences of Creptotrema in a clade (Creptotrema clade sensu stricto) composed of C. creptotrema, the new species described herein, and all species previously described as Auriculostoma, revealing that Auriculostoma is best interpreted as a synonym of Creptotrema based on the principle of priority of zoological nomenclature. Creptotrema funduli, the single sequence of the genus previously available, was not grouped within the Creptotrema clade sensu stricto, suggesting the need for reevaluation of the taxonomic status of this species. Our results showed that Creptotrema represents a monophyletic genus of trematodes widely distributed across the Americas, which currently comprises 19 valid species of parasites of teleosts and anurans.

The parasite communities of two freshwater catfishes (Auchenipterus osteomystax and Trachelyopterus galeatus) were analyzed during the dry and rainy seasons in a Neotropical floodplain. The nature of river-floodplain systems places specific demands on parasite community structure, due to changes in the host environment. It was therefore hypothesized that flood conditions lead to an increase in the richness and abundance of fish parasites in the rainy season at the mouth of Aguapeí River floodplain. The Auchenipterus osteomystax parasite community was richer (11 vs. eight) in species than T. galeatus, although the latter exhibited a greater parasite burden (F1,108 = 126.99, P<0.0001). During the rainy season both host species demonstrated high levels of parasitism (least squared means ± SE = 1.69 ± 0.05 vs. 1.34 ± 0.05; F1,108 = 21.45, P<0.0001). Differences were found in the composition of the parasite species and the proportion of parasites for each host species and between each seasonal period. Flood conditions during the rainy season caused a change in the composition and structure of the parasitic communities. The results corroborate the hypothesis that floods are one of the most significant influences on shaping the parasite communities of fish in floodplains. Our greatest concern is the reduction these dynamics and effects bring about on local biota and, consequently, in host-parasite interaction. We would therefore like to take this opportunity to warn environmental agencies and hydroelectric companies about the importance of the conservation of the diversity of this location.

Aphanoblastella magna n. sp. is described from the gills of the heptapterid catfish Pimelodella avanhandavae Eigenmann, 1917 in southeastern Brazil (Paraná River Basin). This new species most closely resembles Aphanoblastella chagresii Mendoza-Franco, Aguirre-Macedo and Vidal-Martínez, 2007 described from a congeneric fish host in Panama, but can be distinguished by the shape of the accessory piece and shape and size of the ventral and dorsal bars. From the other species of the genus, A. magna n. sp. differs mainly in the shape of the male copulatory organ (MCO), which is sinuous, versus spirally coiled in other species of the genus, except for A. travassosi (Price, 1938), and by the accessory piece which resembles a ‘shoehorn’. Aphanoblastella magna n. sp. is the seventh species of the genus and the first dactylogyrid described from P. avanhandavae. A partial 28S rDNA gene sequence of the new species is also provided; it forms a monophyletic clade with two congeners for which molecular data are available.

SummaryPhilocorydoras longus sp. n. (Dactylogryridae) is described from the gills of the freshwater fi sh Hoplosternum littorale (Hancock, 1828) (Callichthyidae) from Jurumirim reservoir, Upper Paranapanema River, São Paulo State, Brazil. This new species belongs to the genus Philocorydoras mainly by possessing a curved cirrus accompanied by an accessory piece attached by a conspicuous fi lament. Philocorydoras longus sp. n. most resembles P. platensis, but differs by having delicate and smaller hooks, grooves in ventral and dorsal anchors, larger cirrus and accessory piece, and ventral bar with a long postero-medial process. Two species of the genus Urocleidoides (U. corydori Molnar, Hanek et Fernando, 1974 and U. margolisi Molnar, Hanek et Fernando, 1974) originally described from the gills of Corydoras aeneus (Gill, 1858) from Talparo River, Trinidad (near Brazil), were transferred to the genus Philocorydoras mostly by the absence of a sinistral vaginal sclerite (i. e., the primary characters of Urocleidoides) and counterclockwise cirral rings (i.e., curved tube, and tapered anteriorly in Philocorydoras). The new species is the fourth species assigned to the genus and the fi rst recorded for Brazil.

No abstract

No abstract

The present study describes three new species of monogeneans parasitizing the gills of anostomid fishes from the Upper Paraná River basin, southeastern Brazil: Jainus beccus n. sp. and Jainus radixelongatus n. sp. on Leporinus friderici, Leporinus octofasciatus, Leporinus striatus, and Megaleporinus elongatus; and Jainus ornatus n. sp. on L. friderici. The new species differ from other congeners by the morphology of the accessory piece. There is a semicircular distal portion resembling a “bird’s beak” in Jainus beccus n. sp. It composed of two subunits—one ventral and more sclerotized, sickle-shaped, and another dorsal with three projections—in Jainus radixelongatus n. sp. There are two elongated and sclerotized subunits, both of which have a sickle-shaped distal portion, in Jainus ornatus n. sp. Supplementary observations not reported in the original descriptions of the type-species Jainus piava Karling, Bellay, Takemoto & Pavanelli, 2011 are proposed, as follows: the presence of a thin and delicate ventral bar, which can vary greatly in shape; an accessory piece not articulated with the MCO’s base. This paper provides the first phylogenetic study based on LSU rDNA and COI mtDNA gene sequences for Jainus, improving and clarifying the understanding of host–parasite relationships in neotropical characiforms.