MSc Student
Advisor: Thomas Schwaha

Unit for Integrative Zoology, Department of Evolutionary Biology
University of Vienna

The family Clavoporidae Osburn & Soule, 1953 represents a specialized group within ctenostome bryozoans, characterized by distinctive pedunculate colonies adapted predominantly to deep-sea environments. Despite their ecological significance and unique morphological features, clavoporids remain insufficiently studied, with current knowledge limited to a handful of described species across five recognized genera: Ascorhiza, Cephaloalcyonidium, Clavopora, Metalcyonidium, and Pseudalcyonidium. This thesis presents a detailed investigation of clavoporid diversity, focusing specifically on morphological analysis and taxonomy. Utilizing newly collected deep-sea samples from New Zealand, Sweden, Antarctica and France, but also museum specimens, a comprehensive morphological dataset was established. Specimen analysis employed advanced stereomicroscopy and measurements of key morphological features such as autozooids, kenozooids, peduncles, capitulum. Additionally, micro computer tomography and standard barcoding genes were examined for selected samples. The results reveal substantial morphological diversity within clavoporid taxa, leading to the identification and description of multiple new taxa at both the genus and species levels. Notably, six new genera and several species are described, significantly expanding the known diversity and morphological complexity of the family. A systematic determination table synthesizing diagnostic morphological criteria is provided for future taxonomy assessments. Comparative analysis with existing taxa underscores both the evolutionary distinctiveness and ecological adaptations of clavoporids, highlighting their role in benthic communities and deep-sea ecosystems. The newly described taxa not only refine our understanding of clavoporid diversity but also have broader implications for marine biodiversity assessments and conservation strategies in poorly explored deep-sea habitats. This study also first describes clavoporids from shallow habitats, which widely extends the bathymetric range of the family. Overall, this research significantly enhances the taxonomic resolution of Clavoporidae, offering foundational data crucial for future ecological, biogeographical, and evolutionary studies of deep-sea bryozoans.