Abyssal ascidians (Chordata, Tunicata) from the Weddell Sea, Antarctica, including a new Styela species and stomach content identifications.

Deep-sea benthic communities from the Weddell Sea, Antarctica, were sampled in JanuaryApril 2005 in an area located between 61S70S and 0W49W. We found a total of eight ascidian species that belong to five different families, of which one corresponded to a new species. These were: Protoholozoa pedunculata Kott, 1969; Corynascidia suhmi Herdman, 1882; Styela andeepensis Maggioni Tatin sp.

Hidden diversity in Antarctica: Molecular and morphological evidence of two different species within one of the most conspicuous ascidian species.

The Southern Ocean is one of the most isolated marine ecosystems, characterized by high levels of endemism, diversity, and biomass. Ascidians are among the dominant groups in Antarctic benthic assemblages; thus, recording the evolutionary patterns of this group is crucial to improve our current understanding of the assembly of this polar ocean. We studied the genetic variation within sensu lato, one of the most widely distributed abundant and studied ascidian species in Antarctica.

Deep-sea ascidians (Chordata, Tunicata) from the SW Atlantic: species richness with descriptions of two new species.

The understudied deep-sea benthic communities from the Southwestern Atlantic continental slope (200 m-3000 m depth) were sampled on August 2012 in an area located around 38°S that included the Mar del Plata submarine canyon. In these samplings we found a total of 16 ascidian species from six different families, of which two corresponded to new species. These were: Aplidium meridianum (Sluiter, 1906); Aplidium variabile (Herdman, 1886); Aplidium marplatensis Maggioni Tatián (sp.