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

The phrynophiurid brittle star Astrotoma agassizii is abundant in the cold temperate Magellanic region of South America and has a circumpolar Antarctic distribution. Three genetically distinct lineages were recently identified, with one in Antarctica geographically and genetically isolated from both South American lineages (Hunter R, Halanych KM. 2008. Evaluating connectivity in the brooding brittle star Astrotoma agassizii across the Drake Passage in the Southern Ocean. J Hered. 99:137-148.). Despite being an apparent brooding species, A. agassizii displayed a high genetic homogeneity at 2 mitochondrial markers (16s and COII) across a geographical range of more than 500 km along the Antarctic Peninsula. Here, using 16s ribosomal RNA sequences, we match a variety of early developmental stages (fertilized eggs, embryos; n = 12) collected from plankton samples in the Ross Sea to sequences of A. agassizii from the Antarctic Peninsula. The single 16s haplotype reported here is an identical match to one 16s haplotype found for A. agassizii from the Antarctic Peninsula, more than 5000 km away. Based on the regular occurrence of A. agassizii developmental stages in plankton samples, we propose that the Antarctic lineage of this species has a planktonic dispersive stage, with brooding restricted to the South American lineages. A different developmental mode would provide further evidence for cryptic speciation in this brittle star.

Molecular Species Identification of Astrotoma agassizii from Planktonic Embryos: Further Evidence for a Cryptic Species Complex