The evolution of the Proteocephalidea (Platyhelminthes, Eucestoda) based on an enlarged molecular phylogeny, with comments on their uterine development

Abstract

We present a molecular phylogeny of the Proteocephalidea based on 28S rDNA sequence data that is a follow-up to the paper by Zehnder & Mariaux (1999). Twenty-three new sequences, including three outgroups are added in our new data-set. The Gangesiinae Mola, 1929 and the Acanthotaeniinae Freze, 1963 appear to be the most primitive clades. They are followed by a robust clade comprising the Palaearctic Proteocephalinae Mola, 1929 from freshwater fishes. The structure of the more derived clades, comprising most Neotropical and Nearctic species, is less resolved. At the nomenclatural level, we erect a new genus, Glanitaenia n. g. for G. osculata (Goeze, 1782) n. comb., previously Proteocephalus osculatus, and define an aggregate for the Palaearctic Proteocephalus Weinland, 1858. After a re-examination of all of the studied taxa, we identify two types of uterine development and show the importance of this character for the systematics of the order. Our phylogeny does not support the classical view of a Neotropical origin for the Proteocephalidea but rather favours an Old World origin of the group either in saurians or Palaearctic Siluriformes.

Cairaella henrii gen. n., sp. n., a parasite of Norops trachyderma (Polychrotidae), and Ophiotaenia nicoleae sp. n. (Eucestoda: Proteocephalidea), a parasite of Thecadactylus rapicauda (Gekkonidae), in Ecuador

“…Rego et Gil de Pertierra, 2005) by the presence of a dense network of cortical osmoregulatory canals, which is unique in proteocephalidean cestodes (Freze 1965, Schmidt 1986, Rego 1994, Rego and Ivanov 2001, de Chambrier et al 2004, 2005. Furthermore, Cairaella differs from all 12 genera by the morphology of the eggs, which have a three-layered embryophore.…”

“…Uterus ventral, with lateral diverticula. Type 1 of uterine development (see de Chambrier et al 2004). Eggs with threelayered embryophore and with small outgrowths on its external surface.…”

“…Formation of uterus of type 1 (see de Chambrier et al 2004): in immature proglottides, uterine stem straight, occupying entire length of proglottis, formed by longitudinal thick band of chromophilic cells along midline of proglottides. Lumen of uterus appearing in first mature proglottides (Fig.…”

Anomotaenia barusi sp. nov. and A. alata (Cestoda, Dilepididae) from Charadrius dubius (Aves, Charadriiformes) in Slovakia, with comments on related species

“…It is strongly recommended to revise the structure of the uterus and living eggs or eggs preserved outside proglottides. This approach could provide important taxonomic information and is successfully applied, e.g., in studies of Proteocephalus (Gil de Pertierra and de Chambrier 2000, De Chambrier et al 2004 and rarely also in some other cestode groups (Georgiev and Gardner 2004). Findings from Slovakia confirm that Anomotaenia should comprise only species with a reticulate uterus and eggs having filaments, as it is characteristic for the typespecies A. microrhyncha.…”

Ultrastructural study of spermiogenesis and the spermatozoon of the proteocephalidean cestode Barsonella lafoni de Chambrier et al., 2009, a parasite of the catfish Clarias gariepinus (Burchell, 1822) (Siluriformes, Clariidae)

“…However, phylogenetically, they have also been regarded as a problematical group (Zehnder and Mariaux 1999, Škeříková et al 2001, Scholz and de Chambrier 2003, de Chambrier et al 2004). In fact, the systematics of Proteocephalidea is far from being suitably resolved (Rego 1994(Rego , 1995Zehnder and Mariaux 1999;de Chambrier et al 2004). …”