Cephalopod biodiversity of the Kermadec Islands: implications for conservation and some future taxonomic priorities

In order to establish the Kermadec–Rangitāhua Ocean Sanctuary, which will protect a large, unique, near-pristine section of New Zealand’s marine environment, an improved understanding of the marine biodiversity of this area is required. Over 150 cephalopod specimens were collected from the Kermadecs during a recent biodiversity survey, providing the first opportunity in over a century to directly assess locally occurring taxa. Specimens were morphologically identified and DNA barcoded. DNA sequences were analysed using the Barcode Index Number (BIN) system in the Barcode of Life Data System. This study nearly doubles the previously known cephalopod biodiversity of the Kermadecs, adding 28 species (bringing the total to 70), and reporting three cephalopod orders from this area for the first time. The BIN analysis highlighted several taxa that are badly in need of revision, including some supposedly monotypic genera that now appear to contain multiple species, and at least five species that may be new to science. The Kermadec region also hosts 34 cephalopod species not known to occur elsewhere in New Zealand waters. Most taxa reported herein are deep-sea species whose habitat is not protected by the existing marine reserve; we therefore strongly support the establishment of the proposed Sanctuary.

DNA barcoding analysis of Coleoidea (Mollusca: Cephalopoda) from Chinese waters

Coleoids are part of the Cephalopoda class, which occupy an important position in most oceans both at an ecological level and at a commercial level. Nevertheless, some coleoid species are difficult to distinguish with traditional morphological identification in cases when specimens are heavily damaged during collection or when closely related taxa are existent. As a useful tool for rapid species assignment, DNA barcoding may offer significant potential for coleoid identification. Here, we used two mitochondrial fragments, cytochrome c oxidase I and the large ribosomal subunit (16S rRNA), to assess whether 34 coleoids accounting for about one-third of the Chinese coleoid fauna could be identified by DNA barcoding technique. The pairwise intra- and interspecific distances were assessed, and relationships among species were estimated by NJ and bayesian analyses. High levels of genetic differentiation within Loliolus beka led to an overlap between intra- and interspecific distances. All remaining species forming well-differentiated clades in the NJ and bayesian trees were identical for both fragments. Loliolus beka possessed two mitochondrial lineages with high levels of intraspecific distances, suggesting the occurrence of cryptic species. This study confirms the efficacy of DNA barcoding for identifying species as well as discovering cryptic diversity of Chinese coleoids. It also lays a foundation for other ecological and biological studies of Coleoidea.