Three New Species of Sciadicleithrum (Monogenoidea, Dactylogyridae) Parasitizing Cichlid Fishes (Cichliformes: Cichlidae) in the Northeastern Peru.

INTRODUCTION: The present study describes three new dactylogyrid species infecting the gill filaments of cichlid fishes (Cichliformes: Cichlidae) from the Amazon basin, Peru: Sciadicleithrum amazoniensis n. sp. on Biotodoma cupido (Heckel, 1840), and Sciadicleithrum feliciajaramae n. sp. and Sciadicleithrum souzatecci n. sp. on Bujurquina peregrinabunda Kullander, 1986. MATERIALS AND METHODS: Some monogeneans were stained with Gomori's trichrome and mounted in Canada Balsam to determine internal soft structures. Others were cleared in Hoyer's medium for the study of sclerotized structures. Drawings were made using a drawing tube and a microprojector. RESULTS: Sciadicleithrum amazoniensis n. sp. is characterized by the presence of a male copulatory organ (MCO) with a coil of approximately 2 counterclockwise rings, an accessory piece articulated to base of the MCO with an expanded proximal end and a bifurcated distal end, and a sinistral vaginal aperture. Sciadicleithrum feliciajaramae n. sp. can be differentiated from all its congeners by its J-shaped MCO with about half a counterclockwise loop and a rod-shaped accessory piece articulated to the base of the MCO, with the distal end bent. Sciadicleithrum souzatecci n. sp. differs from all other members of Sciadicleithrum by having an elongated MCO with about a clockwise loop and a funnel-shaped base. Additionally, Sciadicleithrum souzatecci n. sp. is characterized by its weakly sclerotized, C-shaped accessory piece with a robust middle process. CONCLUSIONS: Present findings are added to the other 26 species previously known in Sciadicleithrum.This is the first data on the parasites of B. peregrinabunda.

Two new Neotetraonchus species (Dactylogyridea, Dactylogyridae) parasitising the Peruvian sea catfish Galeichthys peruvianus (Siluriformes, Ariidae), including molecular data.

As part of a parasitological survey, several specimens of two new monopisthocotylean species, Neotetraonchus celsomanueli sp. nov. and N.peruvianus sp. nov. (Dactylogyridea, Dactylogyridae), were collected from the gill filaments of the Peruvian sea catfish Galeichthys peruvianus (Siluriformes, Ariidae) off Puerto Pizarro, Tumbes region, Peru. Neotetraonchus celsomanueli sp. nov. is characterised by an MCO with a T-shaped distal end and an accessory piece that is ribbed and expanded proximally with a worm-shaped termination. Neotetraonchus peruvianus sp. nov. is typified by its MCO, which has a sledgehammer-shaped distal end and an accessory piece with a claw-shaped distal end. Additionally, N.peruvianus sp. nov. is characterised by its jellyfish-shaped onchium. A partial 28S rDNA sequence was obtained from N.celsomanueli sp. nov., and a phylogenetic analysis was conducted. This analysis revealed the phylogenetic position of Neotetraonchus celsomanueli sp. nov. within a clade comprising monopisthocotylean parasites of diadromous and marine ariid catfishes, including Hamatopeduncularia spp., Chauhanellus spp., Thysanotohaptor Kritsky, Shameem, Kumari & Krishnaveni, , and Neocalceostomoides spinivaginalis Lim, 1995. This finding brings the number of known Neotetraonchus species to seven and represents the first described Neotetraonchus species infecting marine catfishes from Peru.

Phylogenetic position inferred on SSU rDNA sequence gene and description of a new parasitic cnidarian (Endocnidozoa: Myxobolidae) infecting Markiana nigripinnis (Teleostei: Stevardiinae) from a small marginal lake floodplain, Brazil.

Herein, a detailed molecular phylogeny analysis was developed to determine the phylogenetic position of a new freshwater histozoic myxosporean cnidarian, Henneguya markiana sp. nov. from the world's largest tropical wetland area, Pantanal, Brazil. The new species is described using an integrative taxonomy approach including morphology, biological traits and molecular data. Phylogenetic analysis inferred by Maximum Likehood method showed the new Henneguya species in a well-supported clade of myxosporean gill parasites of South American characids fishes. In this same clade, the new Henneguya described appeared in a sub-clade clustering with H. lacustris and H. chydadea. Nevertheless, the sequences of the new species and H. lacustris and H. chydadea have a large genetic divergence of 10.4% (148 nucleotides-nt) and 10.5% (147 nt) respectively. To the best of our knowledge, this is the first report of a cnidarian myxosporean species parasitizing a fish from Stevardiinae from South America. In the light of the differences observed from the integrative taxonomy, we are confident that this isolate is a new species of Henneguya, increasing the knowledge of diversity of this enigmatic group of cnidarians.

Morphology and molecular phylogeny of Pauciconfibuloides amazonica gen. n. sp. n. (Platyhelminthes, Monogenoidea) parasitizing the Amazonian croaker Plagioscion squamosissimus.

An integrative study was performed to understand the phylogenetic relationships of an undescribed, freshwater species of microcotylid parasitizing Plagioscion squamosissimus from the Amazon River Basin. Based on morphological and molecular analysis (18S rDNA and partial 28S rDNA genes), a new genus is proposed to accommodate this new species, Pauciconfibuloides amazonica gen. n. sp. n. The new genus is closely related to Protastomicrocotylinae and Pauciconfibula by sharing the vagina, male copulatory organ, and genital atrium all unarmed. However, Pauciconfibuloides gen. n. can be distinguished from those taxa by the prostatic system and position of the vaginal pore. Molecular phylogenetic inference suggests a sister relationship with species of Polylabris (Prostatomicrocotylinae), but to date, there are no available 18S or 28S rDNA sequences of Pauciconfibula to be compared. This is the first report of a microcotylid parasitizing a freshwater sciaenid from South America.

Morphological and molecular characterization of Ameloblastella pirarara sp. n. (Monogenoidea: Dactylogyridae) parasitizing the large Amazonian catfish Phractocephalus hemioliopterus.

In this study, integrative taxonomy is applied to describe a new dactylogyrid species, Ameloblastella pirarara sp. n. from the gills of Phractocephalus hemioliopterus, a commercially and ecologically important Amazonian catfish. Ameloblastella pirarara sp. n. can be distinguished from its congeners mainly by the morphology of the male copulatory organ (MCO), accessory piece, and anchors. The new species most resembles Ameloblastella unapi, from the Peruvian Amazon, but differs from it by the number of MCO rings, morphology of the vaginal canal and sclerotized structures of the haptor. Phylogenetic analyses based on sequences of the partial 28S rDNA (D1-D2 domains) gene placed the new species in a well-supported subclade of Ameloblastella spp. parasites of Neotropical siluriform fish, as a sister taxon to Ameloblastella unapioides. Thus, the new species described herein expands our knowledge of the diversity of monogenoid parasites from Amazonian freshwater fish.

Infestation by Ergasilus coatiarus (Copepoda: Ergasilidae) in two Amazonian cichlids with new host record from Peru: An ectoparasites natural control approach.

The occurrence of copepods ergasilid was investigated in two species of cichlids of economic importance for aquaculture in the Amazon region: Cichla monoculus and Chaetobranchus semifasciatus. The fish were collected from a semi-intensive fish farm, near the city of Nauta, Loreto State, Peru. Copepods were found in the gill filaments of 44 of 85 specimens (51.7%) of C. monoculus and in eight of 30 (26.6%) specimens of C. semifasciatus. The parasite was identified as Ergasilus coatiarus based on its morphological features. The occurrence did not vary significantly with host size (P≥0.05) in both species. This is the first report of E. coatiarus parasitizing C. semifasciatus in the Amazon basin and the first report in C. monoculus from Peru. The high occurrence of these copepods in the present study points out the need of improving the strategies of parasitic prevention and control in order to better prevent future disease outbreaks.