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Water-level fluctuations can have significant effects on lake biological communities. Thirlmere Lakes are a group of five interconnected lakes located near Sydney. Water levels in Thirlmere Lakes have fluctuated over time, but there has been a recent decline that is of significant concern. In this study, we examined over one year the species composition and richness of zooplankton (Rotifera, Cladocera and Copepoda) and abiotic conditions in Lakes Nerrigorang and Werri Berri, two of the five Thirlmere lakes, with reference to lake water level. We recorded a total of 66 taxa of zooplankton, with the first report of the rotifer Notommata saccigera from Australia, and the first report of the rotifers Keratella javana, Lecane rhytida and Rousseletia corniculata from New South Wales. There was a marked difference in abiotic conditions between the two lakes, with more variable conditions in Lake Nerrigorang. There was a significant positive correlation between zooplankton species richness and lake water level but only for Lake Nerrigorang. Although the two lakes are closely situated and thought to be potentially connected at high water levels, they show distinct ecological characters and the effect of water-level fluctuations on zooplankton species richness seems to differ between the lakes.

While patterns in diversity and biogeography of macroscopic organisms may be fairly well-documented, this is much less the case for microscopic organisms, for which mechanisms working at entirely different scales may be relevant. Data deficiency remains a major obstacle to the study of these mechanisms, and this situation is exacerbated in regions for which accessibility is not self-evident. We here report on the Lepadellidae rotifers in zooplankton samples collected during the Boyekoli ebale Congo 2010 expedition and a subsequent visit to Yangambi, DR Congo in June 2012. The material contained eight hitherto unknown species amongst 33 Lepadellidae taxa. This remarkable result illustrates a previously unknown and largely endemic microfauna of the Congo Basin and refutes the “African anomaly” hypothesis on the purported poverty of the Central African rotifer fauna. We describe the new species, viz. Colurella asymmetrica n. sp., Lepadella hanneloreae n. sp., L. jingruae n. sp., L. weijiai n. sp., L.wilungulai n. sp., L. yangambi n. sp., Squatinella curviseta n. sp. and S. longipila n. sp., and comment on the diversity and biogeographical relationships of this fauna. Two of the new species appear to have a South American congener as their closest relative, potentially constituting two more examples of rare African-South American vicariant species-pairs in Rotifera.

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.

Understanding patterns and processes in biological diversity is a critical task given current and rapid environmental change. Such knowledge is even more essential when the taxa under consideration are important ecological and evolutionary models. One of these cases is the monogonont rotifer cryptic species complex Brachionus plicatilis, which is by far the most extensively studied group of rotifers, is widely used in aquaculture, and is known to host a large amount of unresolved diversity. Here we collate a dataset of previously available and newly generated sequences of COI and ITS1 for 1273 isolates of the B. plicatilis complex and apply three approaches in DNA taxonomy (i.e. ABGD, PTP, and GMYC) to identify and provide support for the existence of 15 species within the complex. We used these results to explore phylogenetic signal in morphometric and ecological traits, and to understand correlation among the traits using phylogenetic comparative models. Our results support niche conservatism for some traits (e.g. body length) and phylogenetic plasticity for others (e.g. genome size).

We test the hypothesis that conochilid rotifers represent an independent family-level taxon within Superorder Gnesiotrocha, by analysing their phylogenetic position based on the 18S rDNA sequence of a large number of representatives of this taxon and its putative relatives. Both Bayesian and maximum likelihood analysis confirm a monophyletic clade of all gnesiotrochans with strong branch supports. Within Gnesiotrocha, Conochilidae form a strongly supported clade with representatives of all but some genera of Flosculariidae. These results refute Conochilidae as separate family-level taxon within Gnesiotrocha. This finding is also supported by a phylogenetic analysis using morphology, in particular new observations on trophi morphology. Conochilid rotifers are likely specialized Flosculariidae, which evolved to a planktonic lifestyle and reduction of coloniality within the group, in contrast to other Flosculariidae. Furthermore, our analysis reveals that two genera of Flosculariidae, Beachampia and Limnias, form a single, strongly supported clade in a sister-group relation to a clade consisting of representatives of Order Collothecacea. The present results, both regarding position of the conochild rotifers and of two genera of Flosculariidae, highlight the need for a more extensive analysis of relationships within Gnesiotrocha.

Based on material from aquatic habitats in the northern Chihuahuan Desert and a literature review, we present an account on the occurrence of genus Rhinoglena in North America. Two new species are described, and the presence of Rhinoglena frontalis in the USA is confirmed. Of the two new species, R. texana n. sp. is a close relative of R. frontalis, whereas R. ovigera n. sp. is unique by being oviparous, in contrast to all other Rhinoglena which are viviparous. This prompts a revision of the generic diagnosis of Rhinoglena to accommodate the new species. An identification key to the known species of the genus is provided.

Floodplain wetlands in semi-arid regions have intricate channel-floodplain networks with highly variable and unpredictable wet and dry phases related to changes in hydrology and geomorphology. We tested the hypothesis that the presence of different hydro-geomorphic habitats in those systems drives structural and functional differences in aquatic communities. To test this hypothesis, we examined the densities and species composition (structural variables), and primary productivity and respiration (functional variables) of plankton communities, and water chemistry in three spatially explicit channel, floodout and lagoon habitat types inundated by environmental water releases in the Macquarie Marshes, semi-arid Australia. Significant differences were recorded among the community-level structural and functional variables among the three habitats. Greater densities of phytoplankton, zooplankton and planktonic bacteria were observed in a hydrologically isolated floodplain lagoon. The lagoon habitat also had greater primary productivity of phytoplankton and planktonic respiration compared with the channel and floodout. Our results suggest that water release to meet environmental flow requirements can be an important driver of planktonic diversity and functional responses in semi-arid wetland systems by inundating diverse, hydro-geomorphically distinct habitats.

The freshwater littoral comprises a mosaic of habitats structured at several scales by a combination of hydrophyte architecture and physiology. Within this complex environment littoral invertebrates should distribute themselves to maximize fitness: that is, for sessile animals selection of permanent substrata is critical, while distribution of motile (periphytic) animals should follow predictions of Ideal Free Distribution theory. Here we explore the relationships between littoral rotifers and hydrophytes by conducting nestedness analyses on 10 published datasets (7 sessile; 3 periphytic); one dataset each of microcrustaceans and insects were included for comparison. We used four metrics to assess nestedness: mean matrix temperature (T); counts of discrepancy shifts and species segregation; and percent singletons. Six sessile rotifer datasets exhibited nestedness (T = 9.25–30.2°, supported by ≥2 null models; the other metrics varied widely). Our results indicate that distribution of sessile rotifers and periphytic insects was highly structured, but until more data is available little can be said about the distribution of the periphytic rotifer or microcrustacean community structure. Sessile rotifer species possessing idiosyncratic temperatures (T>T +1.5 SD) exhibited a trend toward a record of cosmopolitanism. Important idiosyncratic hydrophytes included Ceratophyllum, Chara, and Utricularia. Two of the three periphytic, rotifer datasets exhibited nestedness (T = 19.2°, 39.9°), but each was supported by only one of the four null models. The periphytic microcrustaceans did not show nestedness, while the insects did (T = 15.5°; supported by four null models). The three other metrics varied considerably among the periphytic datasets, showing no discernable pattern.

Appeltans, Ward ... et al., Background: The question of how many marine species exist is important because it provides a metric for how much we do and do not know about life in the oceans. We have compiled the first register of the marine species of the world and used this baseline to estimate how many more species, partitioned among all major eukaryotic groups, may be discovered. Results: There are ∿226,000 eukaryotic marine species described. More species were described in the past decade (∿20,000) than in any previous one. The number of authors describing new species has been increasing at a faster rate than the number of new species described in the past six decades. We report that there are ∿170,000 synonyms, that 58,000-72,000 species are collected but not yet described, and that 482,000-741,000 more species have yet to be sampled. Molecular methods may add tens of thousands of cryptic species. Thus, there may be 0.7-1.0 million marine species. Past rates of description of new species indicate there may be 0.5 ± 0.2 million marine species. On average 37% (median 31%) of species in over 100 recent field studies around the world might be new to science. Conclusions: Currently, between one-third and two-thirds of marine species may be undescribed, and previous estimates of there being well over one million marine species appear highly unlikely. More species than ever before are being described annually by an increasing number of authors. If the current trend continues, most species will be discovered this century. © 2012 Elsevier Ltd., WoRMS has benefited from funding as part of several EU projects: Network of Excellence in Marine Biodiversity and Ecosystem Functioning (MarBEF), Pan-European Species directories Infrastructure (PESI), Distributed Dynamic Diversity Databases for Life (4D4Life), the Global Biodiversity Information Facility (GBIF), and the Census of Marine Life (CoML). It originated in the European Register of Marine Species (ERMS) that was funded by the EU Marine Science and Technology (MAST) research program

Global biodiversity patterns are often driven by different environmental variables at different scales. However, it is still controversial whether there are general trends, whether similar processes are responsible for similar patterns, and/or whether confounding effects such as sampling bias can produce misleading results. Our aim is twofold: 1) assessing the global correlates of diversity in a group of microscopic animals little analysed so far, and 2) inferring the influence of sampling intensity on biodiversity analyses. As a case study, we choose rotifers, because of their high potential for dispersal across the globe. We assembled and analysed a new worldwide dataset of records of monogonont rotifers, a group of microscopic aquatic animals, from 1960 to 1992. Using spatially explicit models, we assessed whether the diversity patterns conformed to those commonly obtained for larger organisms, and whether they still held true after controlling for sampling intensity, variations in area, and spatial structure in the data. Our results are in part analogous to those commonly obtained for macroorganisms (habitat heterogeneity and precipitation emerge as the main global correlates), but show some divergence (potential absence of a latitudinal gradient and of a large-scale correlation with human population). Moreover, the effect of sampling effort is remarkable, accounting for >50% of the variability; this strong effect may mask other patterns such as latitudinal gradients. Our study points out that sampling bias should be carefully considered when drawing conclusions from large-scale analyses, and calls for further faunistic work on microorganisms in all regions of the world to better understand the generality of the processes driving global patterns in biodiversity.

To contribute to the biogeographical knowledge of rotifers, we critically re-evaluate the species of Lecanidae recorded from Thailand. We report on a number of rare (L. armata Thomasson, L. bulla diabolica Hauer, L. chinesensis Zhuge and Koste) and one new species of Lecane. Lecane latissima Yamamoto is recognized as the senior synonym of Lecane thailandensis Segers and Sanoamuang, L. kostei De Ridder is reestablised as valid name for the cold-water bipolar taxon formerly referred to as L. latissima. Some dubious and dated records of taxa are reconsidered. In total, we confirm 92 species of Lecane from the country, which is almost half of the world's diversity of the taxon, and a limited degree of endemics to various scales, from countrywide to Paleotropical. These results are in accord with the moderate endemicity model of distribution and diversity patterns in microscopic organisms. A potential new avenue of research may be to unravel cryptic diversity in species complexes such as the L. ludwigii, L. lunaris, L. bulla, L. leontina and L. quadridentata species groups as models of tropical and subtropical micrometazoans. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

WOS: 000282859700011, Salinity and temperature are known to be important factors driving species richness and species composition in inland waters, but their effect and interaction are still not completely clear. In this paper we examine their interaction on species richness and species composition of planktonic rotifers in Turkey, controlling for other confounding effects. Eighty-four species of Rotifera belonging to 32 genera were recorded from eight sampling sites in Develi Plain (Middle Anatolia, Kayseri, Turkey), collecting repeated samples in different seasons (April, July, October and December 2007), and measuring water parameters (electrical conductivity, pH and temperature). Generalised Linear Models and Mixed Effect Models were used to disentangle the effect of the environmental parameters on species richness and composition. Temperature positively affected species richness as expected from previous studies. Whereas this effect was clear in the freshwater habitats (less than 1000 mu S cm(-1)), it was not observed at all at higher salinities. Surprisingly, species richness significantly increased with salinity in subsaline waters between 1000 and 6000 mu S cm(-1). Species composition varied among sampling sites (accounting for 36.2% of total variation), but no other factors were found to be involved., TUBITAK [107T922, TBAG-HD363], This paper is a part of the first author's PhD thesis and supported by TUBITAK (107T922, TBAG-HD363).

This paper reviews several neutral models as possible mechanisms for simulating and explaining so-called “hollow curve distributions.” The models include simple random assignment, MacArthur's broken stick, Preston's lognor-mal (but as simulated by Sugihara), Fisher's logseries, and Hubbell's unified neutral theory of biodiversity and biogeog-raphy. Each model is fitted to data describing the distribution of genera over families in the phylum Rotifera.

We present a summary of the results included in the different treatments in this volume. The diversity and distribution of vertebrates, insects, crustaceans, molluscs and a suite of minor phyla is compared and commented upon. Whereas the available data on vertebrates and some emblematic invertebrate groups such as Odonata (dragonflies and damselflies) allow for a credible assessment, data are deficient for many other groups. This is owing to knowledge gaps, both in geographical coverage of available data and/or lack of taxonomic information. These gaps need to be addressed urgently, either by liberating date from inaccessible repositories or by fostering taxonomic research. A similar effort is required to compile environmental and ecological information in order to enable cross-linking and analysis of these complementary data sets. Only in this way will it be possible to analyse information on freshwater biodiversity for sustainable management and conservation of the world’s freshwater resources.

During August 1999, the authors conducted a sampling campaign in the PDR Laos, in order to contribute to the chorology of rotifers in the region. Two samples, collected from a rice paddy and an adjacent pond near Vientiane, Laos, contained a total of 135 rotifer species including several that appear new to science or that warrant taxonomical or biogeographical comments. No new species can be named, but Cephalodella boettgeri Koste and Floscularia armataSegers are recorded for the second time ever after their description from South America, and Parencentrum lutetiae (Harring and Myers) and Polyarthra luminosaKutikova are new to Southeast Asia. This raises the number of rotifers recorded from Laos from 9 to 130. The diversity recorded is remarkable, especially when compared with that of similar habitats in the Thai part of the floodplain of River Mekong and its tributaries. Different agricultural practices may account for the difference in species richness. Similar highly diverse rotifer faunas are known to occur in natural, tropical and subtropical floodplain systems only. This accords with the view that rice paddies can be regarded as artificial wetlands or floodplain systems, which, if managed taking biodiversity concerns into account, may have a potential for the conservation of freshwater biodiversity. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Phylum Rotifera comprises about 2030 known species classified in three main groups, the marine Seisonida (3 species), the Monogononta (1570 species) and the unique, exclusively parthenogenetic Bdelloidea with 461 clonal species. Here I present an annotated checklist of the taxon, giving the global distribution of the valid species. This checklist contains over 3,000 available names at the genusand species-group level, including valid names and a non-comprehensive list of synonyms. A number of taxonomic and nomenclatural suggestions following from the review is presented. Suggestions include several new synonyms and two nomina nova: Dissotrocha kostei for Dissotrocha aculeata Koste, 1996 non Ehrenberg, 1838 (stat. nov., ex. Dissotrocha hertzogi aculeata) and Lepadella zigzag for Lepadella bractea Myers, 1934 non (Ehrenberg, 1838). This contribution also describes features of an on-line, global names database of the Rotifera, on which this checklist is based.

In order to address the dearth of information on Rotifera in Vietnam, and especially on rotifers inhabiting freshwater psammon in Southeast Asia, we collected and examined twenty-five hygropsammon samples from Bau Thiem Lake, Thua Thien Hue Province, central Vietnam. A total of eighty-nine species-level rotifer taxa were identified, belonging to 21 genera and 13 families. Of these, 48 taxa (54%) are new to Vietnam, including three species, Lecane climacois HarringMyers, 1926, Notommata cerberus (Gosse, 1886) and Trichocerca intermedia (Stenroos, 1898) that are new to the Oriental region, and three species, Lecane phapi n. sp., Lecane dorysimilis n. sp. and Trichocerca bauthiemensis n. sp. that are new to science. These, and some additional rare species are commented upon and illustrated. We estimated that the α-diversity of psammon rotifers in Bau Thiem Lake may be as high as 99 (SD=8.4; Chao2) or 115 (Jacknife2) taxa. These results indicate a high potential of rotifer diversity in the hygropsammon at Bau Thiem Lake, central Vietnam.

We describe some rare epizoic rotifers found on Potamon fluviatile (Herbst, 1785) from Italy. Three species are discussed: Lecane branchicola (Piovanelli, 1903) (Monogononta, Lecanidae; new synonym: L. piovanellii Bartos, 1957), Anomopus telphusae Piovanelli, 1903 and Embata parasitica (Giglioli, 1863) (Bdelloidea: Philodinidae). Lecane branchicola, previously considered a nomen nudum after Bartos (1957), is redescribed, and its identity is stabilized by the designation of a neotype. Both L. branchicola and A. telphusae are particularly rare, and have been found on a few occasions only. Lecane branchicola appears to be restricted to a specific body part of their host, namely the branchial chamber. On the contrary, E. parasitica has been recorded as epizoic from several hosts and regions. SEM photographs of the trophi of the three species are presented.

We report on the γ- diversity of Rotifera in freshwater habitats of the River Mun floodplain, Northeast Thailand. Qualitative samples were collected during the pre-monsoon (April) and post-monsoon (October) periods of 2000, from 70 habitats spanning a diverse array of freshwater habitat types. Of the 184 species identified, most belong to Lecane (31.0%), followed by Trichocerca (12.0%), Lepadella (11.4%) and Brachionus (8.2%). Oriental, Australasian, and Eastern hemisphere taxa account for 4.3%, 3.3% and 7.1%, respectively, of the total rotifer fauna, and 8.8%, 1.7% and 10.5%, respectively, of Lecane. Although comparison between studies is difficult, these numbers conform to previous reports on the diversity and composition of the rotifer fauna of Thai freshwater habitats, and of tropical floodplain ecosystems. Diversity is lowest during the post-monsoon period, which may result from disturbance by monsoon conditions. Two morphospecies, Brachionus srisumonaen. sp., and Lecane niwati n. sp., are described as new to science. Additional noteworthy occurrences are, Lecane robertsonae Segers, previously considered a Neotropical endemic, and L. subtilis Harring & Myers, a tropicopolitan species new to Thailand and the Oriental region.

Measurements, line drawings and scanning electromicrographs are provided of Baujardia mirabilis gen. n., sp. n., isolated from pitcher fluid of Nepenthes mirabilis from Thailand. The new genus differs from all known nematodes in having two opposing and offset spermatheca-like pouches at the junction of oviduct and uterus. It also differs from most known Rhabditida in having four cephalic setae instead of papillae. Phylogenetic analysis of small subunit rDNA sequence data robustly places the new genus within Panagrolaimidae as a sister taxon to Panagrellus. These unusual nematodes resemble Panagrellus in body size (1.8-2.7 mm in females, 1.3-1.9 mm in males) and in the monodelphic, prodelphic female reproductive system with thickened vaginal walls and prominent postvulval sac. However, they differ from Panagrellus in the characters mentioned above, in their comparatively longer stegostom and in the shape of the male spicules. Because of its aberrant characters, inclusion of this new genus in Panagrolaimidae requires changes to the family diagnosis.

During an ongoing study of the rotifer diversity in Thai peat swamps, several new or rare species were found. We here report on one new species, Lecane kunthuleensis n.sp., from a canal in Kun Thu Lee peat swamp, and on three rare species: Paracolurella aemula (Myers, 1934) and Lecane junki Koste, 1975 from Kra Jood peat swamp (Suratthanee province), and Lepadella punctata Wulfert, 1939 from To-Daeng peat swamp (Narathiwas province).

We studied the rotifer fauna of one of the most pristine peat-swamps in the Southern Thai province of Narathiwas, To Daeng peat swamp. The samples yielded a total of sixty-seven rotifer species. Of these, three -Keratella mixta (Oparina-Charitonova), Lecane enowi Segers & Mertens and Monommata dentata Wulfert- are new to the Oriental region and the Thai fauna, one, Keratella taksinensis n. sp., is new to science. The fauna consists mainly of cosmopolitan (sensu lato) species, complemented by some Paleotropical and endemic taxa, and is dominated by littoral-benthonic taxa, especially Lecane and, to a lesser extent, Lepadella.

In order to help elucidate confusion in the nomenclature of Rotifera (= Syndermata), an updated checklist is provided, including corrections and additions of family- and genus-group names presently considered valid in the Phylum. The species diversity of the Rotifera is illustrated by estimates of the number of valid, named species in each genus. The validity of Paranuraeopsis Koste, 1974 is rejected based on a re-evaluation of its diagnostic features. It is synonymized with Anuraeopsis Lauterborn, 1900. The name Beauchampiella Remane, 1929 is recognized as the valid replacement name for Eudactylota Manfredi, 1927 non Walsingham, 1911 (Insecta), with preference over Manfredium Gallagher, 1957. The priority of Lepadellidae Harring, 1913 over Colurellidae Wesenberg-Lund, 1930 is commented upon.

This study is a first report of rotifer form the South of Mexico. The rotifers were collected from the fishponds arround Biological Division, UJAT and we examined their morphometric characters, cultivated and identified them. We conducted experiment at different salt concentrations tested at 0g L–1 water (no add NaCL), 2g L–1, 4g L–1, 6g L–1, 8g L–1, 10g L–1 water. The species were identified as Brachionus angularis Gosse (1851) characterized by having two anterior spines, which are almost invisible while B. quadridentatus brevispinus Ehrenberg (1832) with six anterior spines, which can be seen clearly. Lorica size of B. angularis and B. quadridentatus brevispinus are about 12.14 and 12.8 m, respectively and the size is much smaller than B. plicatilis (Mazatlan strain).

in finfish larval rearing often depends on the production of phytoplankton as well as zooplankton. Phytoplankton serve as feed for the zooplankton which, in turn, nourish the fish larvae. Different size and types of zooplankton may be raised for different larval stages. Feed production at all stages must be consistent in quality and quantity for the duration of the hatchery cycle if larval rearing is to be successful. We investigated native freshwater rorifer Brachionus angularis, B. quadridentatus brevispinus, and. B. durgae where the last one is reported as a rare an uncommon species in the world which have been collected in Tabasco. The report of freshwater rotifer from Tabasco is divided in two parts, part 1 describes freshwater rotifer from Tabasco, Mexico, as live food, and how to culture them. The second part reports on two species which have been succesfully cultivated in laboratory.

During our study of biodiversity of Rotifera in PR China, as model taxon of freshwater Micrometazoa, we came across several records that warrant revision regarding species of genus Mytilina Bory de St. Vincent, 1826 (Rotifera, Monogonta, Mytilinidae). In addition to this review we describe a new species encountered during examination of freshwater habitats of Inner Mongolia, P.R.China. This new species, Mytilina wangi n. sp., appears to belong to the Mytilina mucronata - ventralis complex but differs from the known taxa in the group by its domed lorica and relatively short toes. We provide an annotated checklist of the Chinese representatives of the genus and discuss the species of the M. mucronata-ventralis group. We suggest treating M. brevispina (Ehrenberg, 1830) and M. ventralis (Ehrenberg, 1830)(synonym: M. macracantha (Gosse, 1886)) as separate species-level taxa rather than as two infrasubspecific variants of the same species, and argue that Mytilina trigona var. bispinosa Wang, 1961 is a misidentified M. acanthophora Hauer, 1938 rather than an infrasubspecific variant of M. trigona (Gosse, 1851).

The distribution and taxonomic composition of Rotifera in Southeast Asia is reviewed. For some countries, records are poor: Brunei, Cambodia and Laos are almost terra incognita for rotifers (< 10 taxa recorded), while the Thai rotifer fauna is the best documented (ca. 310 taxa on record). However, analysis of the available data is impeded by fuzzy taxonomy and the questionable reliability of many records. Most studies focus on the pelagic or littoral of freshwater habitats. Other habitats are largely ignored. Similarly, few studies deal comprehensively with illoricate Monogononta, sessile Flosculariacea and Collothecacea and, especially, Bdelloidea. The genera Lecane, Brachionus and Trichocerca are the best represented, with littoral taxa predominant. Fisheries-related studies dealing with highly productive pelagic environments tend to over report the contribution of Brachionus. Most taxa are thermophilic character, exemplified by the dominance of tropic-centred Lecane and Brachionus. Some cold-water taxa have been recorded, but the relative climatological homogeneity of the region and low number of studies on high-altitude environments prevent the discrimination of clear latitudinal or altitudinal variation in the distribution of rotifers within Southeast Asia. The majority of Southeast Asian rotifers are widely distributed, including true cosmopolites and thermophilic taxa. There are several local or Oriental endemic Rotifera, mostly Lecane. The American Brachionus havanaensis and Keratella americana appear to have been introduced to the region. The taxonomy of some Rotifera described from the region is commented upon; Brachionus murphyi Sudzuki is recognised as senior synonym of B. niwati Sanoamuang et al. (syn. nov.). Some cases of geographical and/or ecological vicariant species-pairs are suggested. The Southeast Asian rotifer fauna contains a sizeable fraction of taxa occurring in the tropical regions of the Old World, most of which also occur in tropical Australia or the Austro-Malayan region. A tropical Australasian faunal component is present, but consists of few taxa only. Hence, affinities between the rotifer fauna of the Ethiopian, Oriental and tropical Australian and Austro-Malayan regions are supported, rather than an affinity between the Indo-Asian or Indo-Malaysian and tropical Australian fauna.

To resolve several taxonomic problems within the family Conochilidae (Rotifera, Monogononta, Flosculariacea), we initiated a comparative study of the morphology in this and related taxa using samples collected from widely separated geographical regions. As part of this study, we paid special attention to trophal morphology using scanning electron microscopy. We also constructed and analysed a data matrix comprising 19 morphological characters of 11 taxa using cladistic methods to uncover all most-parsimonious trees. The results indicate that Conochilidae share a body form with Flosculariidae, but they possess a trophal structure which clearly differentiates them from all other Flosculariacea; thus, the diagnosis of the family Conochilidae is amended to incorporate morphological characters of the trophi. The analysis of our data matrix yielded a single, most-parsimonious tree. From the topology of that tree and our scanning electron microscopy observations, we propose the following: (1) the status of Conochilidae as a separate suborder of Flosculariacea is rejected; (2) taxonomic separation of Conochilus and Conochiloides as subgenera of Conochilus is confirmed; and (3) Lacinularia causeyae Vidrine, Mclaughlin & Willis, 1985 is reallocated to a new genus within the family Conochilide, Conochilopsis gen. nov., as Conochilopsis causeyae (Vidrine et al.) comb. nov.

As part of a survey of the rotifer fauna of Burundi, Lecanidae from Kashira and the floodplain of the river Rusizi in Northwest Burundi are reported. Thirty-four species of Lecane were found. Twenty-five of them are new to Burundi, raising the total Burundian Lecane record to thirty-five. Three species, Lecane aeganea Harring, 1914, L. eswari Dhanapathi, 1976 and L. subulata (Harring & Myers, 1926) are new to the African fauna, the presence of L. baimaii Sanoamuang & Savatenalinton, 1999 in Africa is confirmed. The fauna consists mainly of cosmopolitan and tropicopolitan taxa, accompanied by several Eastern Hemisphere taxa, and one each of pantropical, endemic and arctic-temperate taxa. The latter, occurring in a high-altitude locality, may be a glacial relict.

The hitherto unknown male of Lecane bulla (Gosse, 1851) is described and figured. It is generally similar to the few known males of other Lecane species. However, whereas the degree of fusion of the toes accords between male and female in other species, this is not the case here: the male of L. bulla has two separate and movable toes, these are completely fused into a single toe in the female. This observation further questions the validity of the taxonomic separation of Lecane in three taxa of generic rank, based on the degree of fusion of the toes. The behaviour and reproduction of Lecane is commented upon.