Taxonomic studies of the Rotifera (Phylum Aschelminthes) from a Central Amazonian varzea lake, Lago Camaleão (Ilha de Marchantaria, Rio Solimões, Amazonas, Brazil)

148 species of rotifers were identified in 22 plankton samples collected in Lago Camaleão, situated on the Ilha de Marchantaria, in the varzea region of the Solimões-Amazonas River system. During the low water period, February, 1981, 33 species were found. During the high water period, July, 1981, after the development of the aquatic vegetation, 138 species were identified. The decomposition of the inundated terrestrial vegetation favors those rotifer species which live on the surface of putrid mud. All are cosmopolitan species of the genera Lepadella, Mytilina, Platyias, Brachionus and Testudinella. Bdelloidea was represented by several species of the genus Rotaria. Several identification errors of former authors were revised, and in this study the following are proposed: Brachionus urceolaris amazonica n. ssp., Keratella nhamunda nov. nom., Lecane (s. str.) aimazoniana nov. nom., Lecane aspasia amazonica n. ssp. New records for the Amazon region include: Lecane (s. str.) stichaeoides HAUER 1938, Mytilina unguipes (LUCKS 1912), Testudinella greeni KOSTE 1981, and Testudinella patina dendradena (DE BEAUCHAMP 1955). Three new taxa are described: Cephatodelta paggia n. sp., Lecane (Monostyla) marchantaria n. sp., and Lepadella (L.) minoruoides n. sp

About the relationship between the zooplankton and fluctuating water levels of Lago Camaleão, a Central Amazonian várzea lake

A two-year study of the composition and abundance of the zooplankton was conducted in an Amazonian vãrzea lake, Lago Camaleão. Rotifers were dominant in terms of both species numbers and density. The extremely low standing-stock observed during the high water period is attributed to prevailing poor oxygen conditions and, during extreme floods, current. The species associations of rotifers also reflect the flooding regime and its consequences

Taxonomic studies of the Rotifera from shallow waters on the Island of Maracá, Roraima, Brazil

Four samples collected in the periodically dry, shallow water ecosystems on the island of Maracá (Roraima, Brazil) were investigated for rotifers. This survey is the first in the area. 159 species were identified and the rotifer community is characteristic of small bodies of water with decomposing vegetation. Most of the rotifer species are cosmopolitan. Dicranophorus sebastus (HARRING & MYERS 1928) and Lecane clara (BRYCE 1892) are new for the Neotropics. Three new species are described: Lepadella christinei, L. tricostata and Testudtnella robertsoni

Rotifers from Ecuadorian waters

195 species, including preservation artifacts which were identified to genus level, were found in 18 samples collected in 12 different waters of Ecuador during September 1988. 178 belong to the order Monogononta and 17 to the order Bdelloidea (Digononta). The highest diversity was in the Amazonian lowland with 161 species; in waters of the pacific coastal area we found 81 species and in the Andes only 63. The poorest Rotifer fauna was in Lake Mojanda in the high mountain region at 3,700 m above sea-level with only 9 species. Some remarks were made on 12 particular species: Collotheca tenuilobata, Floscularia melicerta, Hexarthra intermedia brasiliensis, H. mira, Manfredium eudactylotum, Monommata grandis, Octotrocha speciosa, Ptygura elsteri, Henoceros falcatus, Macrotrachela multispinosa and Mniobia russeola

Rotifera from Sri Lanka (Ceylon) 2. Further studies on the Eurotatoria including new records

In the first paper of this series, Chengalath and Fernando (1973) dealt with the genus Lecane from Sri Lanka. In all, twenty five species were recorded, of which seventeen species were new records. Two new species were also described. On the present paper the authors deal with the rest of the Eurotatoria. Again they have found many new records. In all 79 species are described in the present paper of which 47 are new records. The present study is based on the examination of over 300 samples from 135 localities including large and small tanks, ponds of various sizes, rice fields, streams and marshes. The collections cover the whole area of Sri Lanka and were taken during different seasons of the year mainly from 1968-1972

Taxonomic studies and new distribution records of Rotifera (Phylum Aschelminthes) from Rio Jatapú and Uatumã, Amazonas, Brazil

In 1983 six plankton samples were collected by Dr. J. A. Nunes de Mello from Jatapú and Uatumã Rivers and these were examined for rotifers. 39 taxa were identified among which, Brachionus adisi n. sp., is a new species, and Microcodon clavus EHRENBERG, 1830 and also Monommata actices MYERS, 1930, are new records for the Neotropical region

Variaciones morfologicas del rotifero Keratella americana (Carlin, 1943) de una laguna de inundacion del rio Orinoco, Venezuela

L'analyse dy rapport de la longueur de l'épine postérieure à celle de la lorica a montré que l'épine postérieure est significativement plus courte pendantles basses eaux que pendant la crue. Compte-tenu des facteurs habituellement associé au polymorphisme de #Brachionus et #Keratella, on émet l'hypothèse que la variation observée est liée à la disponibilité de la nourriture. Une longue épine postérieure serait un avantage en période de moindre nourriture (période de hautes eaux) tandis qu'à l'étiage une courte épine serait profitable quand la disponibilité des proies augmente. Il a aussi été observé que de faibles variations d'abondance d' #Asplanchna, prédateur du rotifère, affectent la densité de #K. americana, mais sans effet notable sur la longueur de l'épine. En se fondant sur la nomenclature existante existante pour #K. cochlearis, nous proposons la désignation de #K. americana Carlin, 1943 (f. #hispida nov. f.) comme super-espèce incluant lees formes #typica (longue épine postérieure), f. #tecta (sans épine postérieure) et, intermédiaires entre ces extrêmes, et en ordre de longueur d'épine décroissante, les formes #micracantha et #tuberculata$. (Résumé d'auteur

Further taxonomical studies of the Rotifera from Lago Camaleão, a Central Amazonian várzea lake (Ilha de Marchantaria, Rio Solimões, Amazonas, Brazil)

175 species of rotifers were identified in samples collected in lago Camaleão, an Amazonian varzea lake. 24 species which had previously been found in the lake (KOSTE & ROBERTSON 1983) did not reoccur, but were "replaced" by 30 others. Among these, new records for the Amazon region include: Atrochus tentaculatus WIERZEJSKI, 1893, Brachionus bidentatus inermis ANDERSON, 1899, Cephalodella catellina catellina (O. F. MÜLLER 1786), Eosphora anthadis HARRING & MYERS, 1922 and Monommata cf. actices MYERS, 1930. One new species is described, Cephalodella friebei, and the present taxonomic status of Filinia saltator (GOSSE 1886) and Macrochaetus serrcus (THORPE 1893) is discussed

To the knowledge of the rotatorian fauna of the "floating meadows" of a shore lagoon in the várzea of Amazonia, Brazil

Das Wurzelwerk eines Büschels treibender Wasserpflanzen aus einer Uferlagune südostwärts Santarems, Brasilien, wurde auf seinen Bestand an Rotatorien hin untersucht. Neben sehr vielen aquatischen Organismen aus anderen taxonomischen Gruppen über die eine oberflächliche Übersicht gegeben wird, wurden 152 Rädertierformen gefunden. 144 Spezies waren determinierbar. Acht Formen hatte die Konservierungsflüssigkeit so entstellt, daß eine genaue Bestimmung unmöglich war. Über eine Reihe von Spezies werden Einzelbesprechungen mit Abbildungen vorgelegt. Es handelt sich um Arten, die für die amazonische Fauna in früheren Arbeiten noch nicht aufgeführt wurden, oder zu deren Taxonomie der Verfasser glaubte, ergänzende Bemerkungen machen zu müssen. Neu für Amazonien sind: Asplanchnopus hyalinus, Baltro calvus, Collotheca campanulata, Colu- rella sulcata, Cupelopagts vorax, Floscularia conifera, F. janus, Harringia rousseleti, Lacinularia flosculosa, Lecane compta, L. elegans, L. signifera ploenensis, Lepadella heterodactyla, L. triba, L. whitfordi, Limnias melicerta, Lindia truncata, Monommata cf. hyalina, Notommata alltntois, Octotrocha speciosa, Ptygura barbata, P. brachiata, P. crystallina, P. furcillata, P. mucicola, P. pectinifera, P. tacita, Scaridium longicaudum, Sinantherina ariprepes, S. procera (?), Taphrocampa annulosa, Trichocerca insulana, T. tophoessa, T. voluta, Habrotrocha ampulla. Lecane armata THOMASSON 1971 wurde ein subspezifischer Status zugesprochen. Sie soll heißen: Lecane gillardi armata (THOMASSON). Außerdem wwde Lecane ercodes HARRING 1914 zu L. ludwigi ercodes (HARRING) umbenannt. Die in der Probe aufgefundenen Rotatorien mit hohen Abundanzgraden darunter bekannte sessile sind Kosmopoliten und können deshalb in ähnlichen Biotopen der paläarktischen Stillgewässer in den Sommermonaten ebenfalls häufig angetroffen werdent. Ihre Nahrung besteht insbesondere aus Bakterien, Detritus, Protozoen und Protophyten, die in diesen Biotopen, in denen Zersetzungsprozesse stattfinden, reichlich vorhanden sind. Eine besondere Note erhält die amazonische Rädertier-Aufwuchsgesellschaft einschließlich der Bewohner ihrer Grenzschicht (Asplanchnopus hyalinus, Harringia rousseleti, Sinantherina- und Trichocerca- Arten) durch eine beträchtliche Anzahl subtropischer und tropischer Formen mit durchweg niedrigen Ab.-Graden. Es handelt sich zumeist um warmadaptierte Tiere, die bereits rings um den Erdball bei gleichen ökologischen Bedingungen gefunden wurden (siehe z.B. Hauer, 1937/38 und WULFERT 1965; 1966). Dagegen sind andere nach bisherigen Wissen nearktische oder neotropische Formen

Rotifera from Sri Lanka (Ceylon) 3. New species and records with a list of Rotifera recorded and their distribution in different habitats from Sri Lanka

In two previous papers, the Eurotatorian fauna of Sri Lanka has been systematically dealt with. Description of 104 species is given in the previous papers. In the present study an additional twenty-two species are described. Of these two are new. The composition of the Sri Lanka Rotifera is discussed in relation to the fauna of other parts of the world. The distribution of the species in different types of habitats is studied on the basis of samples. A complete list of all Rotifera recorded from Sri Lanka so far is given for easy reference. Examples of localities where species were collected are also given