Phylogenetic position of the marine ciliate, Cardiostomatella vermiforme (Kahl, 1928) Corliss, 1960 inferred from the complete SSrRNA gene sequence, with establishment of a new order Loxocephalida n. ord. (Ciliophora, Oligohymenophorea)

Eur J Protistol. 2006 Jul;42(2):107-14. doi: 10.1016/j.ejop.2006.01.004. Epub 2006 Apr 17.

Abstract

The small subunit rRNA (SSrRNA) gene was sequenced for Cardiostomatella vermiforme, a large marine ciliate the systematic position of which is uncertain but which has been regarded as a scuticociliate for about forty years. The present work indicates that this organism, together with a closely related species, Dexiotrichides pangi, always form a separate assemblage as a sister group to the scuticociliates sensu stricto. The fact that the clade comprising Cardiostomatella and Dexiotrichides branches between the typical scuticociliates and Hymenostomatia, and shares a series of morphological and morphogenetical characters with both, supports the conclusion that it belongs to an intermediate group between the two. We suggest that this group represents a new order, Loxocephalida n. ord. within the subclass Scuticociliatia, which possibly contains all taxa within the families Loxocephalidae and Cinetochilidae and with Loxocephalidae as the type family.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • Bayes Theorem
  • DNA, Protozoan / chemistry
  • DNA, Ribosomal / chemistry
  • Genes, rRNA / genetics*
  • Molecular Sequence Data
  • Oligohymenophorea / classification*
  • Oligohymenophorea / genetics*
  • Oligohymenophorea / ultrastructure
  • Phylogeny*
  • RNA, Protozoan / genetics
  • RNA, Ribosomal / genetics
  • Sequence Alignment
  • Species Specificity

Substances

  • DNA, Protozoan
  • DNA, Ribosomal
  • RNA, Protozoan
  • RNA, Ribosomal

Associated data

  • GENBANK/AY881632