Amythas membranifera was originally described through a single and incomplete specimen found in Commonwealth Bay, Adelie Land, Antarctica, at similar to 600 m depth. The species occurs exclusively in Antarctic waters and has a great ecological and biological value to benthic dynamics in some Antarctic areas. We collected several specimens of A. membranifera at Marian Cove, Maxwell Bay (King George Island) during a cruise of the project "CHAnges in Coastal Marine Systems of the Antarctic Peninsula: a 2050 Outlook (CHAMP2050)". We present here a detailed study of A. membranifera from new specimens collected during this cruise, including morphological redescription, morphometry, molecular biology studies and aspects of their distribution, reproduction and feeding. A. membranifera specimens present an intraovarian oogenesis with blood vessel association for yolk precursor transference, with mature oocytes with 180-260 mu m in diameter. Our data may suggest a broadcast spawner strategy. The spermiogenesis follows with the maturation of spermatids in spermatozoids in smaller clusters of cells and stored freely in the coelom prior to spawn ect-aquasperms. Finally, we point that one of the most intriguing aspects to date is its distribution, since most recent records were made in the West Antarctic Peninsula region while few records were made in the region of the original description (East Antarctic). This is our contribution to the knowledge of this species encompassing different scientific topics in a integrative perspective.
