Molecular phylogeny of Neotropical monogeneans (Platyhelminthes: Monogenea) from catfishes (Siluriformes)

Abstract

BackgroundThe phylogenetic relationships of dactylogyrids (Monogenea: Dactylogyridae) parasitising catfishes (Siluriformes) from the Neotropical region were investigated for the first time.MethodsPartial sequences of the 28S rRNA gene of 40 specimens representing 25 dactylogyrid species were analysed together with sequences from GenBank using Bayesian inference, Maximum likelihood and Parsimony methods. Monophyly of dactylogyrids infecting catfishes and the Ancyrocephalinae was evaluated using the Approximately Unbiased test.ResultsThe Ancyrocephalinae is a paraphyletic group of species clustering in three main clades as follows: (i) clade A comprising freshwater dactylogyrids from the Holarctic parasitising perciforms clustering together with species (Ameloblastella, Unibarra and Vancleaveus) parasitising Neotropical catfishes; (ii) clade B including species of Dactylogyrus (Dactylogyrinae) and Pseudodactylogyrus (Pseudodactylogyrinae) along with Ancyrocephalus mogurndae, and marine dactylogyrids with cosmopolitan distribution, parasites of scorpaeniforms and perciforms, along with the freshwater Cichlidogyrus and Scutogyrus (infecting African cichlids [Cichlidae]) and (iii) clade C containing exclusively dactylogyrids of siluriforms, freshwater and marine, with Palaearctic, Ethiopian, Oriental and Neotropical distributions; species of Aphanoblastella and Dactylogyridae gen. sp. 4 from the Neotropical region clustering together with species allocated in the Ancylodiscoidinae, along with species of Cosmetocleithrum, Demidospermus and Dactylogyridae gen. spp.ConclusionsThe position of the Ancylodiscoidinae within a larger clade of dactylogyrids (ancyrocephalines) indicates that this subfamily does not represent a natural group. Instead, species allocated to this clade (dactylogyrids of siluriforms along with species of the Ancylodiscoidinae) should be considered as a separate subfamily within the Dactylogyridae. The erection of this taxon requires the search for morphological diagnostic characters in addition to phylogenetic information. A similar strategy should be considered for a new classification of the paraphyletic Ancyrocephalinae. Members of the three clades do not seem to share obvious morphological synapomorphies nor clear patterns in host-parasite associations, zoogeographical distribution or ecology. Clade A should be considered as the Ancyrocephalinae sensu stricto since it includes the type species Ancyrocephalus paradoxus Creplin, 1839. A new subfamily should be proposed to accommodate species currently allocated to Ancyrocephalinae clustering within clade B. Future attempts to propose a new classification of the subfamilies in the Dactylogyridae should include the phylogenetically diverse Neotropical dactylogyrids.

Morphology, molecular and systematic analyses of Bychowskyella (Monogenea: Dactylogyridae) in siluriform fish from India

“…Identification of three species of Bychowskyella from India Such an approach is essential to evaluate phylogenetic relationships (Boeger & Kritsky, 2001;Šimková et al, 2003;Pouyaud et al, 2006;Mendoza-Palmero et al, 2015).…”

A revised description of Synodontella zambezensis Douëllou et Chishawa, 1995 (Monogenea: Ancyrocephalidae) from the gills of Synodontis zambezensis (Siluriformes: Mochokidae) from South Africa

“…It has been shown in a recent study of Mendoza-Palmero et al (2015) that parasites of different genera of various catfi shes are not always closely related and create paraphyletic lineages. Dactylogyrids parasitizing Neotropical catfi shes create clades with those from the Holarctic parasites of perciformes hosts and all others dactylogyrids of siluriforms with Palearctic, Ethiopian, Oriental and Neotropic form a separate clade (Mendoza-Palmero et al, 2015). The paraphyly of dactylogyrid genera is the most probable explanation for the fi nding of the present study.…”

“…The effort to fi nd the phylogenetic position of Synodontella species among dactylogyrid parasites of Siluriformes did not provide satisfying results. The SSU and LSU rDNA regions are often used for inferring phylogenies among various groups of dactylogyrids (Pouyaud et al, 2006;Wu et al, 2007;Mendlová et al, 2010;Šimková et al, 2013;Mendoza-Palmero et al, 2015). It has been shown in a recent study of Mendoza-Palmero et al (2015) that parasites of different genera of various catfi shes are not always closely related and create paraphyletic lineages.…”

“…The SSU and LSU rDNA regions are often used for inferring phylogenies among various groups of dactylogyrids (Pouyaud et al, 2006;Wu et al, 2007;Mendlová et al, 2010;Šimková et al, 2013;Mendoza-Palmero et al, 2015). It has been shown in a recent study of Mendoza-Palmero et al (2015) that parasites of different genera of various catfi shes are not always closely related and create paraphyletic lineages. Dactylogyrids parasitizing Neotropical catfi shes create clades with those from the Holarctic parasites of perciformes hosts and all others dactylogyrids of siluriforms with Palearctic, Ethiopian, Oriental and Neotropic form a separate clade (Mendoza-Palmero et al, 2015).…”

First record of Unibarra paranoplatensis Suriano & Incorvaia, 1995 (Dactylogyridae: Monogenea) on Sorubim lima (Siluriformes: Pimelodidae) from Brazil

“…Dactylogyridae species are the most abundant family in continental waters of South America (LUQUE et al, 2017). The genus Unibarra Suriano & Incorvaia, 1995 is monoespecific Unibarra paranoplatensis Suriano & Incorvaia, 1995, which was described in the gills from Zugaro zungaro Humboldt, 1821 is found in Pimelodus maculatus (Argentina); Aguarunichthys torosus (Peru), with geographic distribution in three countries of South America (Figure 1), in Amazon, Orinoco, Paraná and Parnaiba river basins (SURIANO & INCORVAIA, 1995;COHEN et al, 2013;MENDOZA-PALMERO et al, 2015). However, this monogenean species has not been reported in Sorubim lima Bloch & Schneider, 1801.…”