Modern alongside traditional taxonomy-Integrative systematics of the genera Gymnangium Hincks, 1874 and Taxella Allman, 1874 (Hydrozoa, Aglaopheniidae)

PLoS One. 2017 Apr 19;12(4):e0174244. doi: 10.1371/journal.pone.0174244. eCollection 2017.

Abstract

We studied the diversity within the former genus Gymnangium in the South West Indian Ocean by using an integrative approach of both traditional (morphology-based) and modern molecular taxonomy. Nine species were recorded in the material collected. A total of 97 16S mitochondrial DNA sequences and 54 Calmodulin nuclear sequences from eight Gymnangium/Taxella species were analyzed. We found both morphological and molecular differences in the studied Gymnangium species that make it necessary to split the genus. It is proposed to revalidate the genus Taxella which is currently regarded as a synonym of Gymnangium. Two species of the genus Taxella (T. eximia and T. gracilicaulis), until now regarded as distinct species based on morphological characteristics, cluster together in one phylogenetic clade. Possible explanations are discussed. Two species from Madagascar new to science are herein described and rare species from the Indian Ocean islands are re-described.

MeSH terms

  • Animal Distribution / physiology
  • Animals
  • Calmodulin / genetics*
  • DNA, Mitochondrial / genetics*
  • Gene Expression
  • Genetic Speciation
  • Hydrozoa / anatomy & histology
  • Hydrozoa / classification*
  • Hydrozoa / genetics*
  • Indian Ocean
  • Indian Ocean Islands
  • Phylogeny*

Substances

  • Calmodulin
  • DNA, Mitochondrial

Grants and funding

The research was funded by the Polish National Science Center grant (UMO-2012/04/M/NZ8/00670) to MR. The publication has been financed by the budget of the statutory activity of the Institute of Oceanology Polish Academy of Sciences and partly by the Polish National Science grant (UMO-2014/15/B/NZ8/00237).