English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We provide the first detailed identification of Barents Sea cold seep frenulate hosts and their symbionts. Mitochondrial COI sequence analysis, in combination with detailed morphological investigations through both light and electron microscopy was used for identifying frenulate hosts, and comparing them to  Oligobrachia haakonmosbiensis  and  Oligobrachia webbi , two morphologically similar species known from the Norwegian Sea. Specimens from sites previously assumed to host  O .  haakonmosbiensis  were included in our molecular analysis, which allowed us to provide new insight on the debate regarding species identity of these  Oligobrachia  worms. Our results indicate that high Arctic seeps are inhabited by a species that though closely related to  Oligobrachia haakonmosbiensis , is nonetheless distinct. We refer to this group as the  Oligobrachia  sp. CPL-clade, based on the colloquial names of the sites they are currently known to inhabit. Since members of the  Oligobrachia  sp. CPL-clade cannot be distinguished from  O .  haakonmosbiensis  or  O .  webbi  based on morphology, we suggest that a complex of cryptic  Oligobrachia  species inhabit seeps in the Norwegian Sea and the Arctic. The symbionts of the  Oligobrachia  sp. CPL-clade were also found to be closely related to  O .  haakonmosbiensis  symbionts, but genetically distinct. Fluorescent  in situ  hybridization and transmission electron micrographs revealed extremely dense populations of bacteria within the trophosome of members of the  Oligobrachia  sp. CPL-clade, which is unusual for frenulates. Bacterial genes for sulfur oxidation were detected and small rod shaped bacteria (round in cross section), typical of siboglinid-associated sulfur-oxidizing bacteria, were seen on electron micrographs of trophosome bacteriocytes, suggesting that sulfide constitutes the main energy source. We hypothesize that specific, local geochemical conditions, in particular, high sulfide fluxes and concentrations could account for the unusually high symbiont densities in members of the  Oligrobrachia  sp. CPL-clade.

Cryptic frenulates are the dominant chemosymbiotrophic fauna at Arctic and high latitude Atlantic cold seeps