A new oligotrich (Ciliophora, Oligotrichia) from Argentina, with redefinition of Novistrombidium Song and Bradbury.

A new oligotrich similar to Novistrombidium was discovered in plankton samples from an artificial tributary of the Salado River, Buenos Aires province, Argentina, in summer 2010. Propecingulum fistoleramalliei sp. n.

Influence of temperature and conductivity on the life-history characteristics of a pampean strain of Brachionus plicatilis.

In the present work, we provide the first approach about the life-history of Brachionus plicatilis in South America. We tested with laboratory experiments the response of the pampean strain of B. plicatilis for two of its main stressors (conductivity and temperature).

First description of the soft part anatomy of Ilyocypris ramirezi Cusminsky & Whatley (Crustacea, Ostracoda) from Argentina, South America.

The anatomy of the soft parts of Ilyocypris ramirezi Cusminsky & Whatley, 1996 is described and illustrated for the first time, based on findings of this species from water bodies in the shallow areas of the Llancanelo basin, south-west of Mendoza Province, Argentina. This species is common in Quaternary and extant environments of the Pampa and Patagonian regions. Its distribution is now extending in Argentina to the Central-West area, locally named "Cuyo region".

Phytoplankton chlorophyte structure as related to ENSO events in a saline lowland river (Salado River, Buenos Aires, Argentina).

We analyzed the phytoplankton present in the lower sector of the Salado River (Buenos Aires, Argentina) for 10 years (1995-2005) and detected significant changes occurring in chlorophyte abundance and species richness during La Niña event (1998-1999), which period was analyzed throughout the entire basin (main stream and tributaries). We compared the physicochemical and biologic variables between two El Niño-La Niña-Southern Oscillation (ENSO) periods - El Niño (March 1997-January 1998) and La Niña (May 1998-May 1999) - to identify possible indicators of a relationship between climatic anomalies and chlorophyte performance. Chlorophyte density increased during the La Niña.

Hypotrichous ciliates (Protozoa: Ciliophora) from a temporary pond in Argentina, with redescription of Apoamphisiella hymenophora (Stokes, 1886) Berger, 1999.

Hypotrichous ciliates collected in the plankton and soil samples from a temporary pond in Buenos Aires province, Argentina, were characterized after live observations and protargol impregnation. Apoamphisiella hymenophora (Stokes) Berger is redescribed and the neotype material deposited. Apoamphisiella hymenophora differs from its congeners in having 2 macronuclear nodules, 1 contractile vacuole with anterior and posterior collecting canals, the absence of cortical granules, 2 cirri behind the rightmost frontal cirrus, 1 postoral cirrus, 6 dorsal rows of dikinetids along with scattered dikinetids on the right body margin, and 3-9 caudal cirri arranged in groups at the ends of dorsal rows 1, 2, and 4.

Morphology and notes on morphogenesis during cell division of Deviata polycirrata n. sp. and of Deviata bacilliformis (Gelei, 1954) Eigner, 1995 (Ciliophora: Kahliellidae) from Argentina.

Described herein are the morphology and certain morphogenetic stages of a new freshwater ciliate species, Deviata polycirrata n. sp., and of Deviata bacilliformis recorded in the soil of a dried temporary pond from Argentina.

Description of Deviata rositae n. sp., a new ciliate species (Ciliophora, Stichotrichia) from Argentina.

Soil samples were taken from a temporary pond located in Buenos Aires province, Argentina, during the dry phase in the summer of 2005. The ciliates were studied alive and after staining with protargol. Deviata rositae n.

Pelagostrobilidium wilberti n. sp. (Oligotrichea, Choreotrichida): morphology and morphogenesis.

Morphology, infraciliature, morphogenetic features, and some ecological data for Pelagostrobilidium wilberti n. sp. are described.