When Everything Converges: Integrative Taxonomy With Shell, DNA and Venomic Data Reveals Conus Conco, a New Species of Cone Snails (Gastropoda: Conoidea)

Mol Phylogenet Evol. 2014 Nov;80:186-92. doi: 10.1016/j.ympev.2014.06.024. Epub 2014 Aug 13.

Abstract

Cone snails have long been studied both by taxonomists for the diversity of their shells and by biochemists for the potential therapeutic applications of their toxins. Phylogenetic approaches have revealed that different lineages of Conus evolved divergent venoms, a property that is exploited to enhance the discovery of new conotoxins, but is rarely used in taxonomy. Specimens belonging to the Indo-West Pacific Conus lividus species complex were analyzed using phenetic and phylogenetic methods based on shell morphology, COI and 28S rRNA gene sequences and venom mRNA expression and protein composition. All methods converged to reveal a new species, C. conco n. sp. (described in Supplementary data), restricted to the Marquesas Islands, where it diverged recently (∼3mya) from C. lividus. The geographical distribution of C. conco and C. lividus and their phylogenetic relationships suggest that the two species diverged in allopatry. Furthermore, the diversity of the transcript sequences and toxin molecular masses suggest that C. conco evolved unique toxins, presumably in response to new selective pressure, such as the availability of new preys and ecological niches. Furthermore, this new species evolved new transcripts giving rise to original toxin structures, probably each carrying specific biological activity.

Keywords: Conidae; Conopeptides; MALDI-TOF-MS; Species delimitation; Toxins; Transcriptomes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animal Shells / anatomy & histology
  • Animals
  • Bayes Theorem
  • Biological Evolution*
  • Conotoxins / chemistry*
  • Conus Snail / classification*
  • Conus Snail / genetics
  • Pacific Islands
  • Peptide Mapping
  • Phylogeny*
  • RNA, Ribosomal, 28S / genetics
  • Sequence Analysis, DNA
  • Transcriptome

Substances

  • Conotoxins
  • RNA, Ribosomal, 28S