EurekaMag.com logo
+ Site Statistics
References:
54,215,046
Abstracts:
30,230,908
PMIDs:
28,215,208
+ Search Articles
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on LinkedInFollow on LinkedIn

+ Translate

When proglottids and scoleces conflict: phylogenetic relationships and a family-level classification of the Lecanicephalidea (Platyhelminthes: Cestoda)



When proglottids and scoleces conflict: phylogenetic relationships and a family-level classification of the Lecanicephalidea (Platyhelminthes: Cestoda)



International Journal for Parasitology 46(5-6): 291-310



This study presents the first comprehensive phylogenetic analysis of the interrelationships of the morphologically diverse elasmobranch-hosted tapeworm order Lecanicephalidea, based on molecular sequence data. With almost half of current generic diversity having been erected or resurrected within the last decade, an apparent conflict between scolex morphology and proglottid anatomy has hampered the assignment of many of these genera to families. Maximum likelihood and Bayesian analyses of two nuclear markers (D1-D3 of lsrDNA and complete ssrDNA) and two mitochondrial markers (partial rrnL and partial cox1) for 61 lecanicephalidean species representing 22 of the 25 valid genera were conducted; new sequence data were generated for 43 species and 11 genera, including three undescribed genera. The monophyly of the order was confirmed in all but the analyses based on cox1 data alone. Sesquipedalapex placed among species of Anteropora and was thus synonymized with the latter genus. Based on analyses of the concatenated dataset, eight major groups emerged which are herein formally recognised at the familial level. Existing family names (i.e., Lecanicephalidae, Polypocephalidae, Tetragonocephalidae, and Cephalobothriidae) are maintained for four of the eight clades, and new families are proposed for the remaining four groups (Aberrapecidae n. fam., Eniochobothriidae n. fam., Paraberrapecidae n. fam., and Zanobatocestidae n. fam.). The four new families and the Tetragonocephalidae are monogeneric, while the Cephalobothriidae, Lecanicephalidae and Polypocephalidae comprise seven, eight and four genera, respectively. As a result of their unusual morphologies, the three genera not included here (i.e., Corrugatocephalum, Healyum and Quadcuspibothrium) are considered incertae sedis within the order until their familial affinities can be examined in more detail. All eight families are newly circumscribed based on morphological features and a key to the families is provided. Aspects of morphological evolution and host associations are discussed in a phylogenetic context for each family and for the order as a whole. Lecanicephalidean genera lacking apical structures were confirmed as the earliest diverging lineages. Proglottid anatomy was determined to be much more conserved and indicative of phylogenetic affinities than scolex morphology. Collectively, the Lecanicephalidea parasitize three of the four orders of Batoidea-their almost exclusive absence from skates (Order Rajiformes) appears to be real; only a few records from sharks exist. At the family level, the breadth of host associations is correlated with taxonomic diversity of the family. The degree to which factors such as intermediate host use or host specificity at any stage in the life-cycle shape these patterns is currently unknown.

(PDF emailed within 0-6 h: $19.90)

Accession: 059265823

Download citation: RISBibTeXText

PMID: 26994689

DOI: 10.1016/j.ijpara.2016.02.002



Related references

Tapeworms of elasmobranchs (Part I) - A monograph on the Lecanicephalidea (Platyhelminthes, Cestoda). Bulletin of the University of Nebraska State Museum, 18: 1-236, 2005

The morphogenesis of paruterine organ and ultrastructures of gravid proglottids of Mesocestoides lineatus (Platyhelminthes: Cestoda). Annual Bulletin of the Society of Parasitology Guangdong Province. December; 16: 30-34, 1994

Adding resolution to ordinal level relationships of tapeworms (Platyhelminthes: Cestoda) with large fragments of mtDNA. Molecular Phylogenetics and Evolution 63(3): 834-847, 2012

Added resolution among ordinal level relationships of tapeworms (Platyhelminthes: Cestoda) with complete small and large subunit nuclear ribosomal RNA genes. Molecular Phylogenetics and Evolution 45(1): 311-325, 2007

New insights on the phylogenetic relationships of the Proseriata Platyhelminthes, with proposal of a new genus of the family Coelogynoporidae. Zootaxa 2537 (15 Jul): 1-18, 2010

Tylocephalum cestoda lecanicephalidea from the cownose ray rhinoptera bonasus with a discussion of its validity and systematic relationships. Proceedings of the Helminthological Society of Washington 51(1): 121-134, 1984

Tylocephalum Linton, 1890 (Cestoda: Lecanicephalidea) from the cownose ray, Rhinoptera bonasus (Mitchill, 1815) with a discussion of its validity and systematic relationships. Proceedings of the Helminthological Society of Washington 51(1): 121-134, 1984

Paraphyly of the Pseudophyllidea (Platyhelminthes: Cestoda): circumscription of monophyletic clades based on phylogenetic analysis of ribosomal RNA. International Journal for Parasitology 36(14): 1535-1541, 2006

Molecular relationships between closely related species of Bothriocephalus (Cestoda:Platyhelminthes). Molecular Phylogenetics and Evolution 7(2): 201-207, 1997

Classification of turtles of the Emydidae family and phylogenetic relationships to other families. Studia Geologica Salmanticensia 1: 105-113, 1984

Level of activation, body temperature, and interpersonal conflict in family relationships. Nursing Research 28(3): 154-160, 1979

Phylogenetic relationships and classification of the higher categories of the new world family phyllostomidae. Systematic Zoology 38: 8-38, 1989

Phylogenetic relationships and classification of the higher categories of the new world bat family phyllostomidae. Systematic Zoology 38(3): 228-238, 1989

Phylogenetic relationships within the Platyhelminthes. Systematics Association Special Volume Series, 143-158 No. 28, 1985

The phylogenetic relationships within the Seriata (Platyhelminthes). Systematics Association Special Volume Series, 159-167 No. 28, 1985