Molecular phylogenetic analysis of Neodiplostomum and Fibricola (Digenea, Diplostomidae) does not support host-based systematics

Abstract

Fibricola and Neodiplostomum are diplostomid genera with very similar morphology that are currently separated based on their definitive hosts. Fibricola spp. are normally found in mammals, while Neodiplostomum spp. typically parasitize birds. Previously, no DNA sequence data was available for any member of Fibricola. We generated nuclear ribosomal and mtDNA sequences of Fibricola cratera (type-species), Fibricola lucidum and 6 species of Neodiplostomum. DNA sequences were used to examine phylogenetic interrelationships among Fibricola and Neodiplostomum and re-evaluate their systematics. Molecular phylogenies and morphological study suggest that Fibricola should be considered a junior synonym of Neodiplostomum. Therefore, we synonymize the two genera and transfer all members of Fibricola into Neodiplostomum. Specimens morphologically identified as Neodiplostomum cratera belonged to 3 distinct phylogenetic clades based on mitochondrial data. One of those clades also included sequences of specimens identified morphologically as Neodiplostomum lucidum. Further study is necessary to resolve the situation regarding the morphology of N. cratera. Our results demonstrated that some DNA sequences of N. americanum available in GenBank originate from misidentified Neodiplostomum banghami. Molecular phylogentic data revealed at least 2 independent host-switching events between avian and mammalian hosts in the evolutionary history of Neodiplostomum; however, the directionality of these host-switching events remains unclear.

Neodiplostomum cf. seoulense (Seo, Rim, Lee, 1964) sensu Pyo et al., 2014 (Trematoda: Diplostomidae Poirier, 1886): morphology, life cycle, and phylogenetic relationships

“…As for the division of the genus Neodiplostomum two groups (Group 3 and Group 4) on both reconstructions (Figure 2, 3), this separation was previously noted by Achatz et al (2022b). Since the type species of Neodiplostomum ( Neodiplostomum spathulaeforme (Brandes, 1888)) is included in Group 4 in the cox1 -based reconstruction, we consider specimens from this group as true Neodiplostomum , while Neodiplostomum americanum Chandler and Rausch, 1947 and Neodiplostomum banghami Penrod, 1947 should be attributed to a different genus.…”

Gastrointestinal Helminths in Wild Felids in the Cerrado and Pantanal: Zoonotic Bioindicators in Important Brazilian Biomes

“…Neodiplostomum , a genus associated with aquatic hosts, such as fish, birds, and certain small mammals, such as Hydromys chrysogaster (water rat or rakali), illustrates the impact of environmental changes, including deforestation and urbanization, on parasite–host dynamics [ 96 , 97 , 98 ]. These alterations influence the water distribution and, subsequently, the distribution of parasites.…”