Phylogeny and systematics of the Proterodiplostomidae Dubois, 1936 (Digenea: Diplostomoidea) reflect the complex evolutionary history of the ancient digenean group

Abstract

The Proterodiplostomidae Dubois, 1936 is a relatively small family of diplostomoidean digeneans parasitising the intestines of reptilian hosts associated with freshwater environments in tropical and subtropical regions. The greatest diversity of proterodiplostomids is found in crocodilians, although some parasitise snakes and turtles. According to the most recent revision, the Proterodiplostomidae included 17 genera within 5 subfamilies. Despite the complex taxonomic structure of the family, availability of testable morphology-based phylogenetic hypotheses and ancient hosts, molecular phylogenetic analyses of the group were practically lacking. Herein, we use novel DNA sequence data of the nuclear lsrRNA gene and mitochondrial cox1 gene from a broad range of proterodiplostomid taxa obtained from crocodilian, fish, and snake hosts on four continents to test the monophyly of the family and evaluate the present morphology-based classification system of the Proterodiplostomidae in comparison with the This article was registered in the Official Register of Zoological Nomenclature (ZooBank) as urn:lsid:zoobank.org:pub:C7731 46C-F377-4C30-A73A-318D21119F9C. This article was published as an Online First article on the online publication date shown on this page. The article should be cited by using the doi number. This is the Version of Record.

Phylogenetic position of Sphincterodiplostomum Dubois, 1936 (Digenea: Diplostomoidea) with description of a second species from Pantanal, Brazil

“…4) was similar to other recent molecular phylogenetic analyses of the group (e.g. Blasco-Costa & Locke, 2017; Hernández-Mena et al ., 2017; Locke et al ., 2018; Achatz et al ., 2019b, c, d, 2020; Pérez-Ponce de León & Hernández-Mena, 2019; Queiroz et al ., 2020; Tkach et al ., 2020). Importantly, both the Diplostomidae and Strigeidae were non-monophyletic.…”

“…4; e.g. Blasco-Costa & Locke, 2017; Locke et al ., 2018; Achatz et al ., 2019b, c, d; Achatz et al ., 2020; Queiroz et al ., 2020; Tkach et al ., 2020). Both Sphincterodiplostomum species possess a well-developed, dorsal tubular invagination in the opisthosoma with a muscular sphincter, which is absent in other members of the Diplostominae.…”

“…The intrageneric pairwise nucleotide comparisons of partial 28S (0.7%) and cox 1 (10.6–11.7%) sequences of Sphincterodiplostomum spp. are similar to the levels of intrageneric variation demonstrated within other diplostomoidean genera (28S: 0–4.4%; cox 1: 3.4–19.8%; see Achatz et al ., 2020 and references therein; Tkach et al ., 2020).…”

“…As noted in recent publications on diplostomoideans (e.g. Achatz et al ., 2019a, b, c; Tkach et al ., 2020), we use the terms prosoma and opisthosoma to refer to the distinct anterior and posterior regions of the body.…”

“…The topology of the Diplostomidae and Strigeidae in the phylogeny resulting from our analysis of 28S ( fig. 4) T.J. Achatz et al Achatz et al, 2019bAchatz et al, , c, d, 2020Pérez-Ponce de León & Hernández-Mena, 2019;Queiroz et al, 2020;Tkach et al, 2020). Importantly, both the Diplostomidae and Strigeidae were nonmonophyletic.…”