The bdelloid rotifer Adineta sp.10, found in the nature reserve NSG Unteres Odertal, Germany
Dear visitor,

The initial idea for this website came up when we wanted to document the ecological work of our highschool which is located in the southern part of the Ruhr-district in Germany, thereby creating an online catalogue of the species occuring in the surroundings of our school. The focus was on the microscopical life in aquatic freshwater environments, i.e. a small pond that has been surveyed for more than 10 years before it was replaced by a new pond. A nearby brook complements the biodiversity with species typical for lotic waters.

The first update followed when the biological (marine and terrestrial) results of our excursions to the mediterranean sea were added.

If one tries to identify microscopical organisms it soon becomes evident that certain species can only be unequivocally identified by comparing them with other closely related species from other habitats. Therefore the online catalog now covers species collected and studied from other locations, first within Germany. One emphasis is now on rotifers. So discoveries from locations of adjoining European countries are included as well. About 450 taxa of rotifers are documented up to now.

Also the section of the marine species has undergone an update by adding images of species from several diving excursions in tropical sea areas.

Michael Plewka

news & updates
limnic plankton in springtime

The limnic plankton in our area differs in many respects from the plankton in summer or fall. Aside from rotifers like Synchaeta pectinata or Synchaera oblonga we found found an abundance of ciliates like Frontonia leucas, Didinium nasutum or Pelagothrix plancticola. Some aspects / reasons why there are seasonal changes in the species compostion of the limnoplankton are explained here (pdf).


Some new rotifers and updates

The bdelloid rotifer Adineta oculata has been found as "contamination" in a protist culture. The bdelloid rotifer Habrotrocha thienemanni var. has been found on the bark of an oak tree in the nature reserve NSG Schwalm /Nette/ Germany. Updated information for Encentrum lutra and Macrotrachela ehrenbergii.


Rotifer images of Dr. Martin Kreutz (10/2019)

Dr. Martin Kreutz, author of the outstanding book about protists and other microscopic organisms from the Simmelried in southern Germany has contributed some fantastic images about some rare rotifers from that location, for example Collotheca atrochoides and Collotheca libera. These photographs seem to be the only ones from these critters and are unique in the www. Other images show some interesting features of the retrocerebral organ of Cephalodella forficata.


Microscopic organisms from Brittany / France (08/ 2019)

Brittany / France is not only an gorgeous place for recreation and sightseeing, but also offers a lot of potential sites for sampling microscopic organisms.
The observation of organisms living in small coastal rock pools reveals some very interesting bdelloid rotifers which seem to be adapted to the desiccation of their environment. Several morphotypes of Adineta (here called Adineta sp. 16 and Adineta sp. 18) or Philodina vorax have been found.
Other rotifers which were found in other habitats are: Albertia reichelti, Aspelta cf macra, Colurella adriatica, Encentrum felis, Rotaria socialis
In the intertidal zone the acoel flatworm Symsagittifera roscoffensis could be observed.
In the tree hole of a sweet chestnut tree (Castanea sativa) a strange morphotype of Paramecium could be observed.


New Adineta morphospecies (06/2019)
Another meeting of the BMG took place at the biological station "Teerofenbrücke" in the nature reserve "NSG Unteres Odertal". Two weeks before the meeting microslides had been exposed at selected aquatic locations to allow the settlement of microscopic organisms on these slides. Also the plankton and periphytic organisms of the billabongs of the river Oder were observed. In the dry moss from a wall of a floodgate a new morphospecies of Adineta was found.
Mesopsammon fauna (05/2019)
Some members of the "Berliner Mikroskopische Gesellschaft" (BMG) had a meeting at the German coast of the Baltic Sea and -among other studies- examined the mesopsammon fauna of the beach of Priwall opposite of Travemünde. The organisms living between the sand grains are highly adapted to their environment. Some organisms that could be observed are: otoplanid flatworms, hairybacks like Turbanella sp. or Hetereoxenotrichula, but also ciliates like Trachelocerca cf sagitta.
Planktonkurs NSG Heiliges Meer (04/2019)
At the end of April, again the plankton course took place at the biological station of the nature reserve "NSG Heiliges Meer". Because of the variety of waters and wetlands in this nature reserve, this course is ideal for microscopists. In addition to the opportunity to observe the aquatic life using the available (or one's own) microscope, the course offers the opportunity, through the practical measurement of physical and chemical data in conjunction with lectures, to learn more about the interaction of abiotic and biotic factors in the ecosystem "lake". Some of the found species include among others: the protists: Vorticella chlorostigma, Gastronauta clatratus, Thuricola folliculata, Heliophrya rotunda, Clathrulina elegans; the rotifers Collotheca campanulata, Cephalodella physalis, Floscularia janus, and the algae: Botryococcus braunii, Gonyostomum semen, Mallomonas caudata and Synura uvella.
Cephalodella stenroosi (03/2019)
The monogonont rotifer Cephalodella stenroosi was found in a pond in Hattingen.
Turaniella vitrea in a sapropelic creek bank in Hattingen/NRW (01.2019)
The hymenostomatid ciliate Turaniella vitrea from the Heierbergsbach in Wodantal. Also the euglenoid flagellates Phacus smulkowskianus and Trachelomonas ellipsoidalis were found there.
A new bdelloid rotifer from the "Arnsberger Wald" (12/2018)
A bdelloid rotifer that looks like a variation of Macrotrachela decora was found on a layer of Trentepohlia-algae in the vicinity of the "Kapellenplatz" in the forest south of Warstein.
A single worm infested by three parasite species (12/2018)
In a sample of the Simmelried near the "Bodensee" a specimen of the oligochaete Nais sp. was found which had been infested by the ciliate Rhabdostyla inclinans and the rotifers Cephalodella parasitica and Albertia naidis.
Microscopic Organisms from Hiddensee (11/2018)
In the course of the Hiddensee-excursion of the Berliner Mikroskopische Gesellschaft, which had been kindly organized by W. Bettighofer (, a lot of interesting microorganisms were found. The findings were influenced by (1) the special environment of the Hiddenseer Bodden and (2) by the focus on organisms that had settled on the surface of microslides that had been exposed in certain liminic and marine environments some weeks before. Some of the species that were found are ciliates like Tintinnids; Aspidisca crenata, Folliculina boltoni, Thuricola folliculata; algae like Pediastrum tetras and rotifers like Colurella dicentra, Encentrum marinum, Testudinella clypeata. The complete list of the documented species is here.
Some Organisms from Sphagnum ponds in Griendtsveen / NL (11/2018)
For the preparation of a meeting of the Naturwissenschaftliche Vereinigung Hagen, some samples were collected from Sphagnum ponds in Griendtsveen/ Netherlands. Some species found are: Collotheca coronetta coronetta, Keratella ticinensis, Lepadella minuta, Microcodides chlaena, Proales doliaris, Synura sphagnicola, and ciliates like Halteria grandinella, Holophrya sp., the hypotrich ciliate Urostyla grandis and its parasite, the suctorian Podophrya urostylae.

Updated information for the ciliate Nassula ornata
Updated information for the gastrotrich Heterolepidoderma and the rotifer Epiphanes senta,
Limnic microscopic organisms from Brittany / France
Ankistrodesmus fusiformis, Brachionus diversicornis, Cephalodella biungulata, a special morphotype of Dicranophorus hauerianus were found in a trench in Bourg Blanc. Rotaria sordida was found in LeConquete.
Marine microscopic organisms from Brittany / France
Some interesting rotifers and protists were found in the harbor ground of Portsall and some tidal pools from the coast of Britanny/ France: Encentrum marinum, Colurella uncinata. In a ditch a morphotype of Dicranophorus hauerianus was found that is different from the descriptions in the literature. Some Ciliates like Enchelys sp. feeding on a ciliate, Diophrys cf scutum, Mesodinium sp./ Myrionecta sp., and the phagotroph dinoflagellate Oxyrrhis marina.
Habrotrocha ligula from NSG Koffituten
A bdelloid rotifer that looks like Habrotrocha ligula has been found in the nature reserve NSG Koffituten near Hopsten (Tecklenburger Land), but also shows some differences.
Updated information for Brachionus angularis, Proales fallaciosa, Proales decipiens, Rotaria citrina, Trichocerca porcellus
Two rotifer species from treeholes
Habrotrocha thienemanni and Habrotocha tripus are two rotifer species that have been found in the treeholes of Fagus silvatica
Rotifers in Frullania moss
Arnold Büschlen, an expert on mosses (swissbryophytes) sent some samples of the liverwort Frullania digitata, the amphigastria of which host a special fauna of bdelloid rotifers like for example Habrotrocha annulata, Mniobia symbiotica or Mniobia scarlatina.
Some plankton and other microscopic organisms from the nature reserve NSH Heiliges Meer
The "plankton course" at the biological station of the NSG Heiliges Meer is always a rewarding event: Because of the variety of waters and wetlands in the NSG, this course is ideal for people who like to study the microscopical life of limnic waters. In addition to the opportunity to observe the aquatic life using the available (or one's own) microscopes, the course offers the opportunity to learn a great deal about the interaction of abiotic and biotic factors in the ecosystem "lake" through the practical measurement of physical and chemical data in conjunction with presentations. Besides diatoms and other algae like Synura spinosa some protists like Vorticella aquadulcis or Coleps hirtus and some rotifers like Collotheca trilobata, Kellicottia bostoniensis, Gastropus minor or Synchaeta with parasites could be found.
Ceratotrocha cornigera

This strange looking bdelloid rotifer has been found in Witten, Germany

Some rotifers from Spitsbergen (Svalbard)
A trip to the islands of Spitsbergen (Svalbard) revealed some rotifers which have not been covered on this website beforef Encentrum uncinatum and E. permolle, and some Bdelloids like Habrotrocha elusa and a strange morphotype of Adineta cuneata.
Some organisms from Bodman & Simmelried / Germany

At the end of September 2017 the traditional meeting of some microscopists from Austria, Switzerland and Germany took place in the beautiful location in Bodman at the Bodensee. In samples from the Bodensee, Mindelsee, and the "Simmelried" some rotifers were found, among others Beauchampiella eudactylota, Collotheca mutabilis, Colurella tesselata, and Mytilina bisulcata, some microscopic details on Squatinella mutica and Trichocerca intermedia. thSome Euglenoids like Trachelomonas ellipsoidalis and Trachelomonas verrucosa var. granulosa have been found as well.

Some new rotifers & additions
As a supplement to the paper of Iakovenko et al. (2015): "Antarctic bdelloid rotifers: diversity, endemism and evolution" some images of the species described are presented here. In this survey some new species have been discovered, for example Adineta coatsae, Habrotrocha vernadskii or Macrotrachela jankoi. Others are endemic like Adineta editae or Habrotrocha angularis. The whole list of the documented species in this website can be found here .
Some organisms from a salt spring
A sample from the "Elisabethquelle" in Bad Frankenhausen/ Südharz revealed some interesting organisms, among others some special protists like Loxophyllum verrucosum, Chlamydodon triquetrus and Lacrymaria salinarum. The rotifers include Encentrum marinum and Lecane arcuata. Also some autotroph organisms were found: Enteromorpha sp.and Melosira nummuloides.
Some new rotifers & additions
Proales doliaris and Brachionus urceolaris from Griendtsveen/NL; Arcella artocrea; Macrotrachela nana ligulata; Habrotrocha collaris with parasites; Rotaria citrina from Ebbemoore/ NRW, Aspidiophorus silvaticus and Encentrum martoides from Norway, Euastrum binale; ; Closterium navicula.
Some rotifers from the Phillipines
Anilao in the Batangas area of Luzon/ Philippines is one of the most rewarding dive locations in the world for underwater macro photographers. But this is not all. A moss sample collected in Club Ocellaris revealed some interesting bdelloid rotifers, among others a new form of Adineta.
Some monogonont rotifers
Pourriotia werneckii (Proales werneckii), Encentrum marinum and Cephalodella cf. tenuior have been found in pond near Hattingen, Germany.
New images for Macrotrachela multispinosa var. brevispinosa, Macrotrachela plicata var. plicata, Philodina flaviceps, Philodina rugosa, Rotaria sordida, Floscularia melicerta.
Abrochtha intermedia from an ephemeral puddle in Germany
Abrochtha intermedia has been found in an ephemeral puddle in Hagen/ Germany. Although this species is supposed to be cosmopolitan this may be the first discovery of A. intermedia in Germany.
Updated information for some rotifers, desmids and protists.
How does Floscularia ringens build its tube?; Some photographic insights in the morphology of the tube building organ. New images for Philodina roseola. New Cosmarium (C.margaritiferum) added.
Updated information for some rotifers, desmids and protists.
Updated information for the monogonont rotifers Lecane hamata, and the bdelloid rotifer Adineta vaga. Images of the desmids Cosmarium margaritatum, Cosmarium tetragonum, Cosmarium speciosum and Closterium archerianum added. A new ciliated protist with lorica Vaginicola cf. terricola found in a moss sample.
Updated information for some rotifers and protists
Updated information for the monogonont rotifers Colurella obtusa, Encentrum mustela, Keratella ticinensis, Pleurotrocha petromyzon, Pleurotrocha sigmoidea, Squatinella mutica var. mutica, and the bdelloid rotifer Philodina citrina. Images of the protists Euglypha acanthophora and Wailesella eboracensis added.
Four new rotifers & some protist images added
A strange kind of Scepanotrocha, probably S.parva, Habrotrocha flaviformis, Macrotrachela festinans and Macrotrachela petulans have been found in NRW. New images for Proales fallaciosa, Urocentrum turbo and Blepharisma lateritium.
Some Microinvertebrates from Svalbard
Encentrum permolle, Macrotrachela nana, Macrotrachela musculosa, a strange kind of Adineta gracilis and some Tardigrades from James I Land, Svalbard.
Some interesting species from the Simmelried near Konstanz, Germany
Macrochaetus subquadratus and some nice protists like Chilodonella caudata and Coleps amphacanthus as well as Trachelomonas armata were found in a bog of the Simmelried venn.
Two rotifers from Czech Republic
Asplanchna priodonta var. henrietta and Brachionus diversicornis were found in Bohemia, Czech Republic.
Notommata pachyura
Notommata pachyura pachyura, a rotifer that can get very big has been found in Hattingen.
On the feeding of Collotheca pelagica
Some insights into the digestive system of Collotheca pelagica.
Beauchampiella eudactylota
Beauchampiella eudactylota has been found in Mecklenburg-Vorpommern, Germany.
Tetrasiphon hydrocora
Tetrasiphon hydrocora has been found in Mecklenburg-Vorpommern, Germany.
Some new images for Scepanotrocha rubra, Cephalodella gracilis and Lecane agilis from new locations.
Kellicottia bostoniensis
Kellicottia bostoniensis has been found in the Ohligser Heide, NRW, Germany.
Enteroplea lacustris
Enteroplea lacustris has been found in the "Rotes Moor" in Mecklenburg-Vorpommern, Germany.
Wahner Heide/ Cologne/ Germany: a great place for rare critters
Three years ago the rare rotifer Ptygura rotifer (Pseudoecistes rotifer) had been rediscovered in the Wahner Heide near Cologne. Now the newly described bdelloid rotifer Otostephanos jolantae has been found there. This is probably the first record for Germany. The monogonont Trichocerca cavia could be documented for this location as well.
Macrotrachela zickendrahti
Macrotrachela zickendrahti has been found in a nature reserve Oberrasen/ South Tirol. This rotifer looks pretty weird with its bizarre spines.
New images for Macrotrachela habita
Macrotrachela habita has been found in a moor-area near the Steinhuder Meer in Lower Saxony/ Germany
Resticula plicata from Bavaria
Resticula plicata has been found in the nature reserve Kendlmuehlfilze in Bavaria/ Germany
Some algae images added
Some new desmids and chlorophyte alge from the Alps and other locations have been added to this site, among others: Cosmarium holmiense, C. subundulatum, C. venustum, Cylindrocystis crassa, Desmidium grevillei, Hyalotheca mucosa, Euastrum ampullaceum, Euastrum crassum, Tetrallantois lagerheimi, Westella botryoides, Xanthidium bifidum.
The eversion of the daughter coenobia of Volvox could be observed.
Some rotifers from South Tirol
At the beginning of Oct. 2014 various soil and moss samples were collected in the Alps of South Tirol. First examinations reveal the rotifers Adineta vaga var. rhomboidea, Adineta tuberculosa , Dissotrocha scutellata and Macrotrachela punctata. A variety of Pleuretra lineata has been found as well.
A new pond-new rotifers
A new pond in Hattingen/NRW reveals some rotifer species not yet described on this site before: Trichocerca bicristata and Testudinella incisa. Hexarthra mira and Collotheca pelagica were found as well in this pond.
Rotaria socialis
The bdelloid rotifer Rotaria socialis from the water reservoir Wuppertalsperre.
Aspidiophorus silvaticus - a strange gastrotrich
The hairyback (gastrotrich) Aspidiophorus silvaticus has been found in a forest near Hattingen. Its habitus is quite unusual for a gastrotrich and resembles that of the rotifer Bryceella.
Macrotrachela tuberilabris
A new bdelloid rotifer has been found in Hattingen: Macrotrachela tuberilabris
Scepanotrocha simplex
The bdelloid rotifer Scepanotrocha simplex has been found in a forest near Hattingen.
Asplanchna sieboldi var. cruciformis etc.
Images for Asplanchna sieboldi var. cruciformis. Corrections and new images for Adineta barbata and Synchaeta longipes.
Some rotifers from Tirol, Austria
The "Pillerseetreffen 2014", held in Tirol, Austria, revealed some interesting rotifer species new to me, e.g. Collotheca edentata, Habrotrocha angusticollis, or Habrotrocha curvicollis. Some new images of Macrotrachela quadricornifera var. quadricornifera, Notommata allantois, Notommata groenlandica, Philodina flaviceps and Philadinavus paradoxus are on exhibition now.
Proales minima from Bavaria
The rotifer Proales minima found in a bavarian pond.
Some new images of Notommata tripus
Images of Notommata tripus from the nature-reserve Schwalm-Nettetal
Some rotifers from Brittany, France
Already in May 2014 some interesting rotifers could be found; eg. Filinia terminalis, Asplanchna (Asplanchnella) girodi, Conochilus dossuarius, 2 variations of Keratella cochlearis and Keratella quadrata and the rare Notholca psammarina.
Revision of the genus Synchaeta
Correction of species names; addition of new images, new species added: Synchaeta longipes
Sinantherina socialis
Images of Sinantherina socialis
Habrorocha novemdens
The rotifer Habrotrocha novemdens found in a bavarian forest.
Dorystoma caudata
The rotifer Dorystoma caudata found in a bavarian pond.
Notommata pseudocerberus
Notommata pseudocerberus found in a bavarian pond.
Trichocerca bidens
Trichocerca bidens found in a bavarian pond.
Otostephanos donneri
Otostephanos donneri found in a bavarian pond
Tetraedriella limbata from Bavarian pond
The Xanthophyte Tetraedriella limbata found in the Bergheimer Baggersee, Bavaria
mysterious rotifers
Observing rotifers for more than 15 years sometimes leads to finding some specimens that are not described in the literature (as far as this literature is available through libraries) or sources from the www. Here are some of them.
Cephalodella ventripes
Cephalodella ventripes found in a water reservoir near Wuppertal/ Germany
4 Rotifers from Sweden
Macrotrachela decora, Macrotrachela cf. nana, Habrotrocha lata and Scepanotrocha semitecta from a Sphagnum-sample in Aneboda, Sweden
New images for Notholca squamula and Notommata cyrtopus
Notholca squamula and Notommata cyrtopus have been found in new locations
Philodina acuticornis odiosa
Philodina acuticornis odiosa from Hattingen/ Germany
two rotifers from Mexico
Adineta ?vaga? and Philodina childi found in Bonampak, Mexico
Macrotrachela habita
Macrotrachela habita found in Hattingen, Germany; images of specimen from Italy added.
Sulawesi dive trip
In November 2013 we had a pleasant stay in the Mapia Resort near manado, the Onong Resort in Siladen and the Lembeh Resort located at the famous Lembeh Strait. Not only has the hospitality in all resorts been overwhelming, but also the knowledge and commitment of the dive guides is fabulous. Here are some images: