Buddenbrockia Is a Cnidarian Worm

  title={Buddenbrockia Is a Cnidarian Worm},
  author={Eva Jim{\'e}nez-Guri and Herv{\'e} Philippe and Beth Okamura and Peter W. H. Holland},
  pages={116 - 118}
A major evolutionary divide occurs in the animal kingdom between the so-called radially symmetric animals, which includes the cnidarians, and the bilaterally symmetric animals, which includes all worm phyla. Buddenbrockia plumatellae is an active, muscular, parasitic worm that belongs to the phylum Myxozoa, a group of morphologically simplified microscopic endoparasites that has proved difficult to place phylogenetically. Phylogenetic analyses of multiple protein-coding genes demonstrate that… 

Cytomorphological peculiarities of Polypodium hydriforme (Cnidaria)

  • E. Raikova
  • Biology
    Journal of the Marine Biological Association of the United Kingdom
  • 2008
The combination of characters displayed by P. hydriforme suggests that this animal is not an aberrant cnidarian, as it was formerly believed, but a relic of a major cNidarian group (class Polypodiozoa) that has undergone reduction due to adaptation to parasitism.


Morphological, evolutionary, internal and external phylogenetic aspects of the four phyla, including Porifera, Cnidaria, Placozoa and Ctenophora, are highlighted and discussed.

Myxozoa in Haeckel’s Shadow

The “new” Cnidaria incorporating oligocellular myxozoans with multicellular cnidarians flouts Ernst Haeckel’s biogenetic law and challenges contemporary hierarchical preconceptions of evolution,

Myxozoa in Haeckels Shadow

The “new” Cnidaria incorporating oligocellular myxozoans with multicellular cnidarians flouts Ernst Haeckel’s biogenetic law and challenges contemporary hierarchical preconceptions of evolution,

Cnidarian phylogenetic relationships as revealed by mitogenomics

These analyses suggest that the shared morphological characters in these groups are plesiomorphies, originated in the branch leading to Medusozoa, and the hypothesis that Staurozoa is the sister group to all the other medusozoans is rejected.

Phylogenetic placement of the enigmatic parasite, Polypodium hydriforme, within the Phylum Cnidaria

Evidence is provided that Polypodium is indeed a cnidarian and is either the sister taxon to Hydrozoa, or part of the hydrozoan clade, Leptothecata, and previously conflicting hypotheses concerning the phylogenetic placement ofPolypodium can be reconciled.

How Cnidaria Got Its Cnidocysts

The two-part hypothetical pathway links the origins of tissues through an early amalgamation of amoebic and epithelial cells to and the later introduction of an extrusion apparatus from bacterial parasites to the Cnidarian germ line.

Cell formation by myxozoan species is not explained by dogma

  • D. Morris
  • Biology
    Proceedings of the Royal Society B: Biological Sciences
  • 2010
An ultrastructural study is conducted to examine how internal cells are formed by a myxosporean parasitizing an annelid, and finds that actinospore parasite stages clearly internalized existing cells; a process with analogies to the acquisition of endosymbiotic algae by cnidarian species.



Solution to the phylogenetic enigma of Tetraplatia, a worm-shaped cnidarian

Data presented here from the large and small subunits of the nuclear ribosome leave little doubt that Tetraplatia is in fact a hydrozoan genus, and its precise phylogenetic position is within Narcomedusae, as some authors had previously deduced based on structural characters.

Origins of Bilateral Symmetry: Hox and Dpp Expression in a Sea Anemone

It is shown that Nematostella uses homologous genes to achieve bilateral symmetry: Multiple Hox genes are expressed in a staggered fashion along its primary body axis, and the transforming growth factor–β gene decapentaplegic is expressed in an asymmetric fashion about its secondary body axis.

Orphan worm finds a home: Buddenbrockia is a myxozoan.

It is concluded that Buddenbrockia is a myxozoan, a contention also made recently from ultrastructural studies (Okamura et al. 2002).

The demise of a phylum of protists: phylogeny of Myxozoa and other parasitic cnidaria.

Reassessment of myxozoans as metazoans reveals terminal differentiation, typical metazoan cellular junctions, and collagen production, and it is recommended that the group as a whole be removed from all protistan classifications and placed in a more comprehensive cnidarian system.

Molecular evidence that the myxozoan protists are metazoans.

Phylogenetic analyses of 18S ribosomal RNA sequences from Myxozoa and other eukaryotes support the hypothesis that myxozoans are closely related to the bilateral animals and suggest that the MyXozoa should be considered a metazoan phylum.

Biodiversity and evolution of the Myxozoa.

A triploblast origin for Myxozoa?

The presence of Hox class genes that are typical of triploblasts in Myxozoa is reported, which confirms MyXozoa's phylogenetic affinity with the Bilateria and reveals an extreme example of parasitic degeneracy.

Ultrastructure of Buddenbrockia identifies it as a myxozoan and verifies the bilaterian origin of the Myxozoa

The ultrastructural study has established the triploblastic organization of Buddenbrockia by confirmation of the presence of an inner layer of cells and 4 sets of longitudinal muscles, and simultaneously revealed that Budden Brockia is a myxozoan and that the myxozoans are derived from bilaterians.

Mesodermal anatomies in cnidarian polyps and medusae.

A hypothesis disputing the diploblast classification of cnidarians is presented without providing further explanations for the apparent diploblasty of the polyp stage and the formation of the subepidermal striated muscle in those Medusozoa lacking the entocodon nodule.

Details of the evolutionary history from invertebrates to vertebrates, as deduced from the sequences of 18S rDNA.

  • H. WadaN. Satoh
  • Biology
    Proceedings of the National Academy of Sciences of the United States of America
  • 1994
Phylogenetic comparisons of the sequences of 18S rDNA suggest the monophyly of the deuterostomes, with the exception of the chaetognaths, and support the hypothesis that chordates evolved from free-living ancestors.