Marine Invertebrates I
Diversity, phylogeny, zoogeography and evolutionary ecology of the Porifera (sponges)
Sponges play an important ecological role as active filter feeders contributing to the nutrient flow in the pelago-benthic coupling. Furthermore, sponges are important in structuring the sea floor where they act hosts creating habitats for other organisms. The evolutionary radiation of poriferan taxa can be seen as one ecological key factor triggering the diversity of benthic communities.
Diversity of Sponges in the deep-sea
Research on sponges of selected deep-sea regions, zoogeographical and ecological comparisons
We use an integrative approach combining molecular techniques with morphological and paleontological data to understanding the history of the diversification of deep-sea Porifera.
Sponges of the Southern Ocean and faunistic comparisons with other deep-sea regions, such as the Arctic Fram Strait, HAUSGARTEN (Cooperation with several teams of AWI Bremerhaven)
Phylogeny of selected key taxa of Antarctic deep-sea Porifera (Sponges) and the history of their radiation (ANTARC-Por, DFG: JA 1063/14, together with Prof. Gert Wörheide, LMU)
Activities especially in the Deep-sea research programmes ANtarctic DEEP-sea und SYSTem Coupling in the Antarktischen Weddel Sea (Cooperation with the ANDEEP-SYSTCO-Teams, leader Prof. Angelika Brandt, Univ. Hamburg).
Dynamics and population evology of sponge fauna on the former ice-shelf Larsen A-B, E` of the Antarctic Peninsula
Regional warming observed at the Antarctic Peninsula since the 1950ies caused a collapse of the Larsen AB ice-shelves in 1995, respectively 2002. The ecological impact of these events is studied by multidisciplinary scientific teams on several Antarctic expeditions (2007, 2011 and 2013) to track and monitor the ongoing oceanographic and ecological dynamic changes.
Assumed speciation processes and colonization of the Larsen shelves by pioneer and deep-sea sponge taxa are tested by comparative morphological and molecular methods as well as parallel investigations of the sponge in-fauna; ecological successions by systematic and quantitative evaluation of ROV transsects.
Palaeoecology and evolution of fossil Porifera, phylogeny of the Hexactinellida (glass sponges)
Porifera are most probably the oldest, still existent Metazoa. Diverse Sponge associations in Lower Cambrian strata prove their early, probably Precambrian evolution. The time of prosperity of sponges was in the Late Mesozoic, when especially Hexactinellida and “lithistid” Demospongiae developed in great diversity and played an important role as reafal constructors, especially in the Late Jurassic and Cretacous sponge reefs World-wide. Whereas the rigid Hexactinellida show a very rich preservation potiential, the non-rigid Lyssacinosida and the Amphidiscophora are rare in fossil record. In special preservation windows, e. g. the chalk of Arnager (Late Cretaceous, Coniacian) of the Baltic Island Bornholm we find their rich fossil documentation.