Publications Günter Purschke: download Günter Purschke.pdf

Reserach Area: Morphology and Phylogeny

Investigations on evolution, systematics, phylogeny and functional morphology are in the focus of interest. Currently these investigations are carried out on annelids, the segmented worms, and those taxa which are presumed to be closely related to them. Special emphasis is laid to the phylogenetic relationships within and validity of Lophotrochozoa.

Morphological investigations on function, systematics, evolution, and phylogeny of Annelida


Histological, immunohistochemical and electron microscopic investigations of selected structures and organs of various Annelida and other taxa of invertebrates with special emphasis on (1) resolution of phylogenetic relationships at different levels of the phylogenetic system, (2) identification of the basic body plan of the respective taxa and its taxon-specific changes and (3) analysis of specific organs and structures with special emphasis on functional morphology and adaptation. Interest is focussed on nervous systems and sensory organs, organisation of musculature of the body wall, the foregut as well as nephridia and genital systems.


On the systematic position of Clitellata and the direction of evolutionary changes within Annelida

The phylogenetic system of the higher taxa of Annelida is one of the least satisfactorily resolved problems in invertebrate systematics and phylogeny, including the position and origin of Clitellata. Two controversial hypotheses present different interpretations of the order in which the evolutionary changes occurred within the group as a whole. One hypothesis sees many characters as primitive for Clitellata and consequently for Annelida as a whole, whereas in the other the same characters are regarded as apomorphic. Since most Clitelllata are either limnetic or terrestrial, the question arises which characters are specific adaptations to these environments rather than plesiomorphies taken from the annelid stem species. Our molecular and morphological investigations clearly speak in favour of the second hypothesis. Moreover, these investigations give clear indications regarding the phylogenetic position of the problematic taxa Hrabeiella, Parergodrilidae and Aphanoneura.


Faunistic and systematic investigations of the marine meiofauna

This project comprises a worldwide faunal-taxonomic assessment and description of new polychaete taxa of the littoral meiofauna with special emphasis on speciation and phylogeny. Another topic is the investigation of the diversity of benthic communities in abyssal deep-sea basins (DIVA; interdisciplinary project in cooperation with numerous working groups from Germany and foreign countries).


Progenesis as a principle of the evolution of new taxa and organization types in Annelida

Progenesis ­ acceleration of sexual maturation in juvenile or larval stages ­ is one way to achieve comparatively large changes in organization even in closely related species. This evolutionary scenario reveals the potential for subsequent adaptive radiation and thus rapid evolution of new types of organization. In various groups of polychaetes progenetic evolution has been inferred from an overall similarity of mature species to early developmental stages of larger species. However, on the basis of morphology alone no conclusion can be drawn as to whether single or multiple evolution occurred in these groups. To address these questions, the probability and frequency of this evolutionary principle are examined by molecular methods.