Drawing by P. Dr. Josef Donner


The RWC is an open access knowledge base of global scope that offers access to rotifer nomenclature, taxonomy and classification, natural history collections, geographic distribution, environmental data, and bibliography for all currently accepted species-, genus- and family-group names in Phylum Rotifera. It serves as an authoritative source for all 4.300+ nominal taxa of genus rank and below, that were named since the start of zoological nomenclature in 1758. It also provides a consistent framework for taxonomic data management; allowing collecting, integrating and arranging of complex future data and knowledge about the group.

The Catalog relies predominantly on verified (expert validation) and verifiable (via referencing) species records. Doubtful records and misidentifications are corrected, or, where they cannot be verified, discarded to unburden rotiferology of records which currently hamper taxonomic analyses and obscure distribution and habitat preference patterns.

Taxonomic coverage includes all free-living groups that are traditionally recognized as belonging to Phylum Rotifera (Monogononta, Bdelloidea, Seisonacea), but not the closely related endoparasitic Acanthocephala. Geographical coverage includes the world's major zoogeographical regions and sub-regions as originally defined by Wallace (1876)1, plus Pacific and Antarctic regions, as well as political divisions from country to provinces.


Limitations and Strengths

The RWC is a work in progress, and is thus incomplete. Occurrence records – other than large-scale zoogeography – and ecology data are particularly patchy, but more are continuously being added to the database, along with associated illustrations and photographs, references, specimen and habitat images. The primary data sources are published and expedition materials, applied research, and specimen data from natural history collections. All of these are, or will be, geo-referenced in WGS84-format to allow tracking rotifer records and localities on the world map.

Some of the data entries are preliminary and have not yet been subject to full verification. In an attempt to crowd-source data quality checks, in addition to our own internal checking, and to overcome practical limitations to what a single scientist can achieve, users are encouraged to get actively involved in curating and providing content. See here for a list of contributors to the RWC.

The comprehensive searchable and browsable nomenclator, and the taxonomic “backbone” with evaluation of nomenclatural and taxonomic status for all 4.000+ nominal taxa of specific or infraspecific rank, are as up-to-date as currently available. This includes synonymies, scanned copies and bibliographic references to original descriptions and subsequent literature records, information on type depositions in 75 repositories, and global biogeography. These cover almost all ca. 2.100+ species and infraspecies that are currently treated as valid. The image database now holds 15.700+ diagnostic illustrations, specimen images, live observations, and habitat documentations (see here for database-statistics).


Rationale and significance

Rotifers are highly diverse and among the most conspicuous of freshwater micro-metazoans, and occupy key positions in aquatic ecosystems. Efforts to use rotifers in environmental surveys and in the evaluation of fresh waters have been made, but their confused taxonomy and the difficulty of identifying them reliably jeopardize their use in applied studies. The significance of rotifers as biological markers is therefore still largely unappreciated. More broadly-based taxonomic surveys and better identification aids are required before rotifers can be used as a powerful tool in aquatic ecological studies.

By means of the RWC we endeavor to increase taxonomic efficiency, stabilize nomenclature, make rotifers more readily accessible for inclusion in biotic surveys, and to stimulate descriptive and ecological research on them, for the benefit of both, basic science and applied aquatic research. It should also help to make these organisms more popular in biodiversity and conservation issues.

Give credit where credit is due

Recommended citation format for the RWC as a whole:

Jersabek, C. D. & Leitner, M. F. (2013): The Rotifer World Catalog. World Wide Web electronic publication. http://www.rotifera.hausdernatur.at/, accessed {date of access}.

Example citation of a taxon page:

Jersabek, C. D. & Leitner, M. F. (2013): Cephalodella hollowdayi Koste, 1986. In: Jersabek, C.D. & Leitner, M.F. (2013): The Rotifer World Catalog. World Wide Web electronic publication. http://www.rotifera.hausdernatur.at/Species/Index/222, accessed {date of access}.


Most recently described taxa:


1) Wallace A. R. 1876. The geographical distribution of animals. Harper, New York.