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This study shows the results of a rotifer faunistic survey in thalassic waters from 26 sites located in northeastern U.S. states and one in California. A total of 44 taxa belonging to 21 genera and 14 families were identified, in addition to a group of unidentifiable bdelloids. Of the fully identified species, 17 are the first thalassic records for the U.S., including Encentrum melonei sp. nov. and Synchaeta grossa sp. nov., which are new to science, and Colurella unicauda Eriksen, 1968, which is new to the Nearctic region. Moreover, a refined description of Encentrum rousseleti (Lie-Pettersen, 1905) is presented. During the survey, we characterized samples by different salinity values and ecosystems and compared species composition across communities to test for possible ecological correlations. Results indicate that both salinities and ecosystems are a significant predictor of rotifer diversity, supporting that biodiversity estimates of small species provide fundamental information for biomonitoring. Finally, we provide a comprehensive review of the diversity and distribution of thalassic rotifers in the United States. The results of the present study increase the thalassic rotifer record for the U.S. from about 105 (87 at species level) to 124 (106 at species level) taxa.

Author(s): Garlasche, Giuseppe; Karimullah, Karimullah; Iakovenko, Nataliia; Velasco-Castrillon, Alejandro; Janko, Karel; Guidetti, Roberto; Rebecchi, Lorena; Cecchetto, Matteo; Schiaparelli, Stefano; Jersabek, Christian D.; De Smet, Willem H.; Fontaneto, Diego | Abstract: We present a data set on Antarctic biodiversity for the phylum Rotifera, making it publicly available through the Antarctic Biodiversity Information facility. We provide taxonomic information, geographic distribution, location, and habitat for each record. The data set gathers all the published literature about rotifers found and identified across the Continental, Maritime, and Subantarctic biogeographic regions of Antarctica. A total of 1455 records of rotifers in Antarctica found from 1907 to 2018 is reported, with information on taxonomic hierarchies, updated nomenclature, geographic information, geographic coordinates, and type of habitat. The aim is to provide a georeferenced data set on Antarctic rotifers as a baseline for further studies, to improve our knowledge on what has been considered one of the most diverse and successful groups of animals living in Antarctica.

Information on the embryonic development of the malleate trophi in Epiphanidae (Rotifera, Monogononta, Ploima) is presented, based on scanning electron microscopy observations in Rhinoglena fertoeensis, R. frontalis, R. kutikovae, R. tokioensis, and Proalides tentaculatus, to contribute to the understanding of this structure of high evolutionary and functional relevance in Rotifera. The first observable and distinctly sclerotized structures were a double row of median transversal sclerites along the longitudinal axis, wherein the future unci, rostellar scleropili, cristae rami, and basal apophyses became recognizable. Fulcrum and manubria arose subsequently; the fulcrum sclerites were longitudinally ordered in a double layer. The rami chambers developed last as lamellar structures. Unci appeared as separate thin, elongate elements, the primary uncini, developing to uncus plates by transversal growth and apposition of sclerite material on the shafts of the uncini. The heads of the uncini showed their greatest development after fusion of their shafts into uncus plates. The interjacent spaces between the heads functioned as a mold, organizing bundles of sclerites which developed into the uniseriate, zigzag-shaped cristae rami. The fulcrum attained its definite shape by elongation of the double layer of rod-shaped sclerites into appressed sclerofibrillae. Manubria became visible as a proximal ridge of sclerites, whereupon a triangular lamella composed of crisscross-oriented sclerites developed distally, growing out to the manubrial chambers. Ramus chambers originated from two longitudinal amorphous lamellae incorporating the median rami sclerites and closing from distal to proximal; subbasal chambers were formed before the basal chambers.

Aquatic faunas in fresh, brackish, and salt waters are usually well defined and differ amongst these three habitats. Nonetheless, some animals are known to be euryhaline, namely present across wide salinity ranges. The wide tolerance of putative euryhaline species has, however been refuted in some cases by DNA taxonomy, which has uncovered cryptic diversity with narrow ecological niches. We aim to improve knowledge on the putative euryhalinism of microinvertebrates and test whether it might actually be a real phenomenon or if euryhaline species are mostly a consequence of our previous inability to identify cryptic species with narrow salinity ranges, as discovered in Brachionus plicatilis. Using morphological analyses and DNA taxonomy, we investigated the species reality and distribution of a putative euryhaline rotifer species, Testudinella clypeata, and evaluated whether cryptic species are ecologically and/or geographically segregated. Different DNA taxonomy approaches concurred in revealing the presence of seven cryptic species within the T. clypeata morphospecies, which, in contrast to what has been previously detected, are actually euryhaline. Moreover, differences in analysed morphological traits were not significantly different amongst cryptic species. This suggests that DNA taxonomy improves our estimates of the actual diversity of microscopic species, in contrast to the morphological approach. © 2013 The Linnean Society of London

WOS: 000387757300009, Cotylegaleata iskenderunensis n. sp. is described from a freshwater wetland (Sariseki) at Iskenderun, Turkey. This is the second species within the genus. Cotylegaleata iskenderunensis n. sp. differs from the only known congener, C. perplexa De Smet, 2007, in the shape of the trunk and foot, and particularly the shape of the cotyle and the structure of the trophi. The diagnosis of the genus and family is amended.

The epibiotic rotifers of a Gammarus pulex (L.) collection from the Ardèche, France are reported. Four species were found, of which Cephalodella jersabeki n. sp. and Proales gammaricola n. sp. are new to science and described. The other species, Dicranophorus cambari Wulfert and Embata laticeps (Murray), are commented upon. SEM micrographs of the trophi are presented, and a new or amended terminology is proposed for some diagnostic trophi parts.

Segers, Hendrik, De Smet, Willem H., Fontaneto, Diego, Hinz, Claus, Hussey, Charles, Michaloudi, Evangelia, Wallace, Robert L., Jersabek, Christian D. (2015): Period of public commentary begins on the revised proposal of species-group level names, and on the proposal of genus-group level names of the Candidate Part of List of Available Names (LAN) in the phylum Rotifera. European Journal of Taxonomy 165: 1-3, DOI: http://dx.doi.org/10.5852/ejt.2015.165

De Smet W. H. & Verolet M. 2009. — On two new species of Proales from France, with reallocation of Dicranophorus liepolti Donner, 1964 and D. secretus Donner, 1951 (Rotifera, Monogononta). Zoosystema 31 (4): 959-973.

Two new morphospecies of the rotifer genus Testudinella (Rotifera, Monogononta, Testudinellidae), T. bicorniculata sp. nov. and T. elongata sp. nov., are described from marine psammon collected in the Mediterranean. T. bicorniculata sp. nov. is characterized by two antero-lateral lorica projections; dorsal and ventral anterior margins undulate with shallow median sinus; foot opening sub-terminal, inverted U-shaped; distal foot pseudosegment short; fulcrum with proximal opening. T. elongata sp. nov. is characterized by its strongly elongate and striate lorica; dorsal anterior margin tri-lobed; ventral margin projecting, almost straight; foot opening sub-terminal, inverted U-shaped; distal foot pseudosegment long; fulcrum with proximal opening. The new species are related to T. obscura Althaus, 1957, which is redescribed. Brief descriptions of the external morphology and trophi, as well as biogeographical information are provided for the other Testudinella species reported from marine and brackish environments. T. pseudoclypeata Bērziņš, 1943 is synonymized with T. elliptica (Ehrenberg, 1834).

A new species of rotifer, Rhinoglena kutikovae n.sp. (Monogononta: Epiphanidae), is described from a freshwater lake in the Bunger Hills, East Antarctica. The new taxon is characterized by the following combination of characters: body conical to vase-shaped; a single toe; distal foot pseudosegment bulged; tail prominent, semi-circular; two small spherical pedal glands with common duct, forming a complex with caudal ganglion; trophi with seven major teeth with offset head and two smaller teeth without offset head. The new species is compared with R. fertoeensis, R. frontalis and R. tokioensis, of which scanning electron microscopic information is presented of the trophi. R. kutikovae n.sp. is probably a relict species that survived Quaternary glaciations in glacial lacustrine refugia on the Antarctic continent.

Two new species of rotifers belonging to the Dicranophoridae are described from marine psammon collected at a depth of 30–40 m in the Mediterranean near the island of Elba, Italy. Myersinella uncodonta sp. nov. is characterized by two colourless eyespots; single, incurved acute apical rami teeth; two needle-shaped, slightly incurved elongate unci; manubria with forked head and crutched cauda; outer margin of rami angular postero-laterally. Myersinella longiforceps sp. nov. is characterized by two large red eyespots; a pair of extremely elongated, gouge-shaped apical rami teeth; two short, needle-shaped unci; manubria with forked head and double-crutched cauda; outer margin of rami rounded laterally, tapering towards fulcrum. This is the first report of the genus Myersinella from marine environments.

A new monotypic rotifer family, Cotylegaleatidae, is proposed for Cotylegaleata perplexa gen. et sp. nov., collected from benthos of an artificial small freshwater lake in Belgium. The new family belongs to the subclass Monogononta, order Ploima. Its distinctive characters include: a hollow cup-shaped structure (sucker ?) surrounding the mouth opening, a non-retractile head shield, a distal foot pseudosegment with two toes and two ventro-lateral spurs, a J-shaped vitellarium, and characteristic specialized virgate trophi with stiletto-shaped epipharyngeal elements.

A total of 43 rotifer taxa, belonging to 14 genera, was identified in 47 psammon and periphyton samples collected in the northern part of the western basin of the Mediterranean Sea. Of these, 10 previously described species are new to the Mediterranean, 10 species are new to science and could be described, and 5 others are potential new ones of which insufficient material was available to warrant a full description. Rotifers formed a constant component of meiofauna, from the eulittoral to at least 8 km off shore and a depth of 66 m. A clear zonation was apparent with one to two species only found in the eulittoral zone and sublittoral fringe, and 42 taxa occurring in the sublittoral zone. The trophi of seven previously known species are redescribed based on scanning electron microscopy. Dicranophorus bulgaricus Althaus, 1957 is redirected to Allodicranophorus gen. nov. and Lepadella pontica Althaus, 1957 to Halolepadella gen. nov.

We gathered taxonomic information regarding the occurrence of rotifers in Antarctica and Subantarctica, producing a database of more than 1100 records from all 93 papers published on the region since the start of research expeditions in the far South. From this literature review, we outline a history of rotifer research in Antarctica. Then, using the database, we address specific questions on biogeographic patterns in species richness in rotifers in Antarctica and Subantarctica. We highlight a complex scenario of differences between areas and latitudinal gradients, differentially affected by problems in sampling bias. The number of species of monogonont rotifers seems to decrease with increasing absolute latitudes, whereas the number of species of bdelloid rotifers generally increases with increasing absolute latitudes.

Two new species of rotifer belonging to the Dicranophoridae, and provisionally placed in the genus Encentrum, are described from littoral psammon from the Ussuriyskiy Bay, Peter the Great Bay, Sea of Japan, Russia. Encentrumkutikovae sp. nov. is characterized by a long foot consisting of three pseudosegments, cylindrical toes, a hexagonal rami outline, and the right ramus showing an accessory chamber with alula. Encentrum ussuriensis sp. nov. is characterized by unusual stout toes with claw, an oblong-ovate and latero-caudal weakly angular rami outline, the right ramus bearing an alula, and the left one showing an accessory chamber.

Limnognathia maerski, class Micrognathozoa, so far known only from Arctic Greenland, is reported from the subantarctic Crozet Islands. Fine morphology of the trophi is redescribed using scanning electron microscopy. Results show that the trophi are composed of the same functional units, i.e. incus, paired mallei and epipharynx, as found in Rotifera Monogononta. The zoogeography of the species is briefly discussed.

Three new species of Rotifera belonging to the genus Encentrum (Monogononta, Dicranophoridae) are described and illustrated. Encentrum barti sp. nov. was found among algae in the Eastern Scheldt estuary, the Netherlands. Its main distinguishing taxonomic features are the rostrum provided with a triangular projection, the conical and slightly incurved toes, and the characteristic trophi. Encentrum listensoides sp. nov. was collected among algae in the Eastern Scheldt estuary, the Netherlands. The main diagnostic features of this new species are the foot composed of three pseudosegments, a single pair of large pedal glands, and the trophi showing asymmetrical unci, evenly curved manubria, and preuncinal teeth set at a right angle to the axis. Encentrum teuidcligitatum sp. nov. was found in hygropsammon of a bight of the North Sea in Belgium. It is diagnosed by its slender, acutely pointed toes, and the trophi bearing a tooth on the inner margin of the subbasal rami chambers.

Samples from arctic sea ice were studied for their rotifer fauna. Ice core samples were collected in the northern Barents Sea and the Laptev Sea from August to October 1993 and in the Greenland Sea from July to August 1994. Eight rotifer taxa, Encentrum graingeri, Proales reinhardti, Synchaeta bacillifera, S. cecilia, S. glacialis, S. hyperborea, S. tamara and S. sp., were found. The geographical as well as the vertical distribution and abundance of the taxa in the ice is discussed, with regard to biotic and abiotic parameters of the sea ice environment. Species redescriptions are given for Synchaeta glacialis, S. hyperborea and S. tamara.

The methods to prepare rotifer trophi for light and scanning electron microscopy are reviewed, and the rapid method used by the author is described. Rotifers are dissolved in a minimal amount of sodium hypochlorite solution on a coverslip, and serially rinsed in distilled water. The entire procedure is done under a microscope using micropipettes.

A new species of rotifer, Cephalodella segersi n.sp., is described from littoral periphyton of the man-made Lake Blankaart, Belgium. The species is closely related to C. catellina and C. fluviatilis. The subspecies C. catellina maior is given species rank. Redescriptions and scanning electron microscope pictures of trophi are given for C. catellina, C. fluviatilis and C. maior.

Aquatic faunas in fresh, brackish, and salt waters are usually well defined and differ amongst these three habitats. Nonetheless, some animals are known to be euryhaline, namely present across wide salinity ranges. The wide tolerance of putative euryhaline species has, however been refuted in some cases by DNA taxonomy, which has uncovered cryptic diversity with narrow ecological niches. We aim to improve knowledge on the putative euryhalinism of microinvertebrates and test whether it might actually be a real phenomenon or if euryhaline species are mostly a consequence of our previous inability to identify cryptic species with narrow salinity ranges, as discovered in Brachionus plicatilis. Using morphological analyses and DNA taxonomy, we investigated the species reality and distribution of a putative euryhaline rotifer species, Testudinella clypeata, and evaluated whether cryptic species are ecologically and/or geographically segregated. Different DNA taxonomy approaches concurred in revealing the presence of seven cryptic species within the T.clypeata morphospecies, which, in contrast to what has been previously detected, are actually euryhaline. Moreover, differences in analysed morphological traits were not significantly different amongst cryptic species. This suggests that DNA taxonomy improves our estimates of the actual diversity of microscopic species, in contrast to the morphological approach.(c) 2013 The Linnean Society of London

Proales litoralis sp. nov. (Rotifers, Monogononta: Proalidae) collected from littoral algae and psammon of the Channel (France) and the Eastern Scheldt (the Netherlands) is described. The affiliation of the new species is discussed.

The epibiotic rotifers of a Gammarus pulex (L.) collection from the Ardeche, France are reported. Four species were found, of which Cephalodella jersabeki n. sp. and Proales gammaricola n. sp. are new to science and described. The other species, Dicranophorus cambari Wulfert and Embata laticeps (Murray), are commented upon. SEM micrographs of the trophi are presented, and a new or amended terminology is proposed for some diagnostic trophi parts.

Following ICZN (1999) Article 79 Chapter 17 http://www.nhm.ac.uk/hosted-sites/iczn/code/), we, with the full support of the international community of rotifer researchers as expressed during subsequent international Rotifera symposia, developed a Candidate Part of the List of Available Names for species and genera of Rotifera from the start of zoological nomenclature to the year 2000.

Many, mostly older, names of animal species are nomenclaturally problematic, either because their orthography is unstable, or they cannot be linked reliably to a taxonomic identity, due to the lack of recognisable descriptions and/or types. Yet, they represent available (sensu International Code of Zoological Nomenclature) names and must be taken into account in zoological works. This situation, with available senior, yet dubious names confounding nomenclature, is undesirable. It creates uncertainties at a time when molecular approaches are revolutionizing our concepts of species diversity, and fails us when the current extinction crisis calls for efficient, accurate, and constructive approaches to document, monitor, and conserve biodiversity. The International Code of Zoological Nomenclature (The Code) provides a means to address this issue by restricting availability, application and orthography of names to those included in the List of Available Names in Zoology (LAN). The Code (Art. 79) allows an international body of zoologists in consultation with the Commission to propose a candidate part of the LAN for a major taxonomic field. We explore this possibility for 3570 species-group names of Phylum Rotifera (of which 665 are problematic), by presenting such a candidate Rotifera part of the LAN. The web site of the International Commission on Zoological Nomenclature (http://www.iczn.org) will hold both the candidate list and a forum to facilitate consultation on the candidate list, while the list itself also can already be freely downloaded from three other Internet sites: http://fada.biodiversity. be, http://rotifer.ansp.org/LAN, and www.hausdernatur.at/rotifera. We give here an overview of the general approach and procedures applied in preparation of the candidate list, and anticipate that our effort will promote the process as well as result in a standard list of names for use in taxonomy, the Global Names Architecture and other biodiversity information initiatives.

BackgroundBiogeographical and macroecological principles are derived from patterns of distribution in large organisms, whereas microscopic ones have often been considered uninteresting, because of their supposed wide distribution. Here, after reporting the results of an intensive faunistic survey of marine microscopic animals (meiofauna) in Northern Sardinia, we test for the effect of body size, dispersal ability, and habitat features on the patterns of distribution of several groups.Methodology/principal findingsAs a dataset we use the results of a workshop held at La Maddalena (Sardinia, Italy) in September 2010, aimed at studying selected taxa of soft-bodied meiofauna (Acoela, Annelida, Gastrotricha, Nemertodermatida, Platyhelminthes and Rotifera), in conjunction with data on the same taxa obtained during a previous workshop hosted at Tjärnö (Western Sweden) in September 2007. Using linear mixed effects models and model averaging while accounting for sampling bias and potential pseudoreplication, we found evidence that: (1) meiofaunal groups with more restricted distribution are the ones with low dispersal potential; (2) meiofaunal groups with higher probability of finding new species for science are the ones with low dispersal potential; (3) the proportion of the global species pool of each meiofaunal group present in each area at the regional scale is negatively related to body size, and positively related to their occurrence in the endobenthic habitat.Conclusion/significanceOur macroecological analysis of meiofauna, in the framework of the ubiquity hypothesis for microscopic organisms, indicates that not only body size but mostly dispersal ability and also occurrence in the endobenthic habitat are important correlates of diversity for these understudied animals, with different importance at different spatial scales. Furthermore, since the Western Mediterranean is one of the best-studied areas in the world, the large number of undescribed species (37%) highlights that the census of marine meiofauna is still very far from being complete.

Many, mostly older, names of animal species are nomenclaturally problematic, either because their orthography is unstable, or they cannot be linked reliably to a taxonomic identity, due to lack of recognisable descriptions and/or types. Yet, they represent available (sensu International Code of Zoological Nomenclature; The Code) names and must be taken into account. This situation is undesirable: available senior, yet dubious names confounding nomenclature. It creates uncertainties at a time when molecular approaches are revolutionizing concepts of species diversity, and fails us when the current extinction crisis calls for efficient, accurate, and constructive approaches to document, monitor, and conserve biodiversity. The Code provides a means to address this issue by restricting availability, application, and orthography of names to those included in the List of Available Names in Zoology (LAN). As allowed by The Code (Art. 79), the international assembly of rotiferologists at the 12th Rotifera Symposium (Berlin, 2009) mandated us to propose to the Commission, a candidate part of the LAN for Phylum Rotifera. We explored this possibility for 3570 species-group names of Phylum Rotifera (of which 665 are problematic), by presenting such a candidate Rotifera part of the LAN; the list is now open for discussion on the web site of the International Commission on Zoological Nomenclature (http://www.iczn.org). This site holds both the candidate list and a forum to facilitate discussion. The list itself also can be freely downloaded from three other Internet sites: http://fada.biodiversity.be, http://rotifer.ansp.org/LAN, and www.hausdernatur.at/rotifera. Here we provide an overview of the general approach and procedures applied in preparation of the candidate list and update the present status of the candidate part of the LAN. We further illustrate how our effort can contribute to a standard list of names for use in taxonomy, the Global Names Architecture and other biodiversity information initiatives.

Two new species of the rotifer genus Testudinella (Rotifera, Monogononta, Testudinellidae), T. pseudobscura sp. nov. and T. quadrilobata sp. nov., are described from the intertidal zone of a brackish-water tidal river and a mangrove swamp on Qi’ao Island in the Pearl River estuary, Guangdong province, southern China. Both species belong to T. clypeata (Muller, 1786)—T. obscura Althaus, 1957 group on account of possessing a proximal fulcrum opening, a slit-like foot opening and living in thalassic waters. The trophi of Testudinella zhujiangensis Wei, De Smet & Xu, 2010 are redescribed, and a key to the marine and brackish-water Testudinella species know to date is presented.

WOS: 000277556400010, A survey of bdelloid rotifers from moss and lichen samples collected in the middle Arctic tundra subzone of Spitsbergen (Svalbard) revealed an unexpected high species richness of 52 taxa, of which 18 fully identified species are new for the region. About one-fifth of the European bdelloid species are present. Moisture regime and geographic localization of the moss appeared the most important ecological features driving differences in species composition between samples., Lifelong Learning Programme; Fund for Scientific Research, Flanders (FWO); Swedish Taxonomy Initiative; Natural Environment Research Council [NE/G013179/1], This research was sponsored by a Lifelong Learning Programme to MK, the Fund for Scientific Research, Flanders (FWO) to WHDS, and a forskarassistent grant from the Swedish Taxonomy Initiative to DF. We thank Dr D. Ertz for the identification of the lichen species, and P. De Bock for allowing us to consult his reference collection of mosses from Svalbard. We also thank Sven Bostrorm for comments on the manuscript, and Ana Marcia Barbosa for her help in mapping sampling localities.

Morphology and systematics of the rotifer genus Pseudoploesoma Myers, 1938 are discussed. The genus is transferred from Synchaetidae to Notommatidae. One species, P. formosum (Myers, 1934), is recognized. Pseudoploesoma greeni Koste, 1978 probably belongs to Notommata but must be considered incertae sedis and species inquirenda on account of its poor description; P. greeni sensu Coussement and Dumont (1980) is identified as Notommata copeus Ehrenberg, 1834.

We confront patterns in the chorology and diversity of freshwater and limnoterrestrial Rotifera with predictions following from the recently revived ubiquity theorem on the distribution of microscopic organisms. Notwithstanding a strong taxonomic impediment and lack of data, both bdelloid and monogonont rotifers appear to conform to the hypothesis’ predictions that local diversity is relatively high compared to global diversity and that cosmopolitism is important. To the contrary, however, a latitudinal diversity gradient is obvious, and endemicity is present, and exhibits diverse patterns. This is illustrated by the case of Keratella rotifers, in which we identify purported relict endemicity hotspots in the east Palaearctic (China) and in temperate and cold regions of the southern hemisphere, and a recent radiation in North America. The apparent paradox may result from an antagonism between rotifer’s high population sizes and presence of potentially highly efficient propagules, versus pre-emption of habitats and local adaptation by resident populations, specific dispersal ability, and ecological and geographical factors. We conclude that distribution patterns of microscopic organisms, as represented by rotifers, most likely span the whole range of alternatives, from full cosmopolitanism to local endemism, and suggest that studying this diversity is more productive to come to an understanding of their chorology and diversity.

Rotifers are microscopic aquatic animals that comprise more than 1800 species. Most rotifer species live in freshwater and limno-terrestrial habitats, while thalassic environments (brackish+seawater) are thought to host few species. No recent review of saline rotifers is available. Here we report the results of a review of the literature concerning rotifers from saline environments, distinguished into three categories: stenohaline, euryhaline, and haloxenous, and found both in truly marine habitats and/or in inland saline waters. A total of about 200 studies, mentioning fully identified rotifers from saline waters, allowed us to list as many as 443 rotifer taxa at either specific, subspecific and infrasubspecific rank, corresponding to 391 nominal species. Truly thalassic taxa, not found in inland saline waters only, accounted for 289, including the ‘stenohaline’ (143) and the euryhaline (146) ones. As for freshwaters, the majority of the thalassic rotifers inhabit the psammon, or display a benthic–periphytic way of life, while the plankton likewise is less species rich and less abundant. The geographical distribution of the brackish and marine rotifers largely reflects the distribution of rotifer investigators, therefore, no biogeographical analysis can be performed yet. In conclusion, the analysis of literature citing rotifers in salt waters, uncovers an unexpected rotifer fauna: the apparent richness of the group in thalassic environments is worthy of being addressed by further investigations, as many species have been reported only by their description, suggesting either considerable endemism or taxonomic errors.

Lindia gravitata, previously considered a synonym of L. tecusa by several authors is redescribed. Body shape and trophi structure show that both species are closely related, and unequivocally differentiated by e.g. toe shape, number of sensory papillae, and shape of subunci and epipharynx. Other related, but insufficiently described congeners are listed. The diagnostic features of the subgenus Halolindia are discussed.

During the austral summer 1997/98, a survey was made of a series of freshwater bodies on the Kerguelen Islands, Subantarctica (49° S-69° E), in the area of Port-aux- Francais and Val Studer. The rotifer fauna from plankton of 17 lentic freshwaters is listed and commented upon. Species richness (39 taxa) and species diversity are fairly low. Only 6 taxa are euplanktic, the others are facultative plankters or littoral/benthic species. Three of the true plankters found are restricted to the Southern Hemisphere, whereas the rest of the rotifers (apart from two unidentified monogononts) shows a wide-spread or cosmopolitan distribution. Thirty-three taxa are new to the Kerguelen archipelago. A comparison is made with the rotifer assemblages observed on other Subantarctic islands. Taxonomic notes on little known species are added. The validity of Cephalodella gibba microdactyla as separate subspecies is rejected, and Filinia terminalis kergueleniensis is recognized as junior synonym of F. pejleri.