Consensus on future research directions in the Phylum Rotifera

Rotifers play key roles in aquatic ecosystems, yet significant uncertainty remains about their diversity and evolution, and basic knowledge is still lacking to address practical challenges related to global change. To identify the major knowledge gaps hindering progress, we carried out a Delphi process both online and during the 17th International Rotifer Symposium, involving more than forty experts working across diverse regions and subdisciplines. A total of 133 research questions were screened for relevance and clarity, and reduced to 100 for online scoring. These were evaluated on a 1-to-10 priority scale, after which 67 questions that exceeded 50% agreement were advanced to an in-person workshop. Through structured discussions and round-table voting, participants identified gold, silver, and bronze priority questions, while also considering the feasibility to address them, resulting in a final consensus set of high-priority questions across basic, applied, and philosophical perspectives. The strong support for questions on taxonomic knowledge transfer, digital curation, and AI-assisted identification highlights the emergence of a methodological subfield that links classical taxonomy with modern computational tools. Likewise, the emphasis on improving genetic markers and connecting DNA sequences with traits shows that molecular research is now viewed as a foundational component of rotiferology. This synthesis provides the first communitydriven roadmap for advancing rotifer research. By articulating shared priorities and clarifying persistent knowledge gaps − including the lack of reliable phylogenies, uneven global sampling, and limited hypothesis-driven work − it establishes a foundation for future collaborative projects, funding strategies, and cross-disciplinary integration.