ALBERT

Description: Ecological work carried out on the Antarctic and Magellan shelves since the first IBMANT conference held at the UMAG, Punta Arenas in 1997 is summarized to identify areas where progress has been made and others, where important gaps have remained in understanding past and present interaction between the Antarctic and the southern tip of South America. This information is complementary to a review on shallow-water work along the Scotia Arc (Barnes, 2005) and recent work done in the deep sea (Brandt and Hilbig, 2004). While principally referring to shipboard work in deeper water, above all during the recent international EASIZ and LAMPOS campaigns, relevant work from shore stations is also included. Six years after the first IBMANT symposium, significant progress has been made along the latitudinal gradient from the Magellan region to the high Antarctic in the fields of biodiversity, biogeography and community structure, life strategies and adaptations, the role of disturbance and its significance for biodiversity, and trophic coupling of the benthic realm with the water column and sea ice. A better understanding has developed of the role of evolutionary and ecological factors in shaping past and present-day environmental conditions, species composition and distribution, and ecosystem functioning. Furthermore, the science community engaged in unravelling Antarctic-Magellan interactions has advanced in methodological aspects such as new analytical approaches for comparing biodiversity derived from visual methods, growth and age determination, trophic modelling using stable isotope ratios, and molecular approaches for taxonomic and phylogenetic purposes. At the same time, much effort has been invested to complement the species inventory of the two adjacent regions. However, much work remains to be done to fill the numerous gaps. Some perspectives are outlined in this review, and sugestions are made where particular emphasis should be placed in future work, much of which will be developed in the frame of SCAR'S EBA (Evolution and Biodiversity in the Antarctic) programme.

Description: Published

Description: In the present study, the genus Mirostenella Bayer (Proc Biol Soc Wash 101:251-256, 1988) is revised. We add to knowledge of the type species of the genus M. articulata Bayer (Proc Biol Soc Wash 101:251-256, 1988) from newly collected material from the Antarctic cruise Polarstern ANT XIX/5, and an illustrated description of this species is included. Cairns and Bayer (Smithson Contrib Zool 629:1-79, 2009) included Dicholaphis delicatula Thomson and Rennet (Sci Rept C Zool Bot 9(3):1-46, 1931) in the genus Mirostenella but after the examination of the type material, it is proposed to include the species in the recently described Plumarella subgenus, Faxiella (Zapata-Guardiola and Lpez-Gonzalez in Sci Mar 76:357-380, 2012). In addition, a new species of Plumarella, Plumarella castellviae sp. nov. from SubAntarctic waters is also described and illustrated. The species has similarities to Mirostenella but differs from it in the absence of organic nodes at bifurcation points and the presence of a sympodial branching pattern. Moreover, a new subgenus, Verticillata, is also proposed to include Plumarella species with polyps arranged in whorls around branchlets.

Description: Published