Comparison of systems of biological indication approved during the course of the joint Anglo-Soviet investigations held under the auspices of the Institute of Hydrobiology of the Academy of Sciences of the Ukrainian SSR

In accordance with the plan for joint Anglo-Soviet scientific and technical collaboration on environmental problems, the comparative evaluation of systems of hydrobiological analysis of the surface water quality started in 1977 at the Regional Laboratory of the Severn-Trent Water Authority in Nottingham were continued in the spring of 1978. The investigations were carried out under the auspices of the Institute of Hydrobiology of the Academy of Sciences of the Ukrainian SSR. Hydrobiological and hydrochemical samples were collected by Soviet and British specialists from the Kiev reservoir and the rivers Dnieper, Sozh, Desna and Snov. The samples were processed on the expedition ships and in the Laboratory for the Hydrobiology of Small Water Bodies of the Institute of Hydrobiology of the Academy of Sciences of the Ukrainian SSR. The possible approved methods to be adopted were evaluated from the samples using the phytoperiphyton, phytoplankton, zooplankton and zoobenthos against a background of hydrochemical characteristics. The study concludes that weather conditions complicated the work on testing the systems of biological indication of water quality and made it inadvisable to use those methods of comparison which were used when similar work was carried out in Nottingham

Ultrastructural Alterations in Lepocinclis acus (Euglenophyta) Induced by Medium with High Organic Matter Content

Ultrastructural changes induced by exposure to excess of organic matter were studied in Lepocinclis acus (ex Euglena acus). The cells isolated from the Matanza River, Buenos Aires, Argentina, were grown in soil water medium (SWM). When transferred to medium enriched with Bacteriological Peptone OXOID®, marked body deformation and a significant shortening and widening of the cells was observed. These changes were unexpected in a species with quite rigid cells, a condition previously shown in studies of the pellicle fine structure. Transmission electron microscopy observations suggest that cellular deformation might be facilitated by an increase in strip number, whereas in the original strips normal ultrastructure was maintained. An increase in number and volume of paramylon grains and vacuoles, as well as the presence of membrane whorls in vacuoles was observed. The fine structure of organisms grown in medium with and without organic matter enrichment was compared, and the systematic and ecological importance of morphological changes triggered by cell deformation was discussed.Fil: Conforti, Visitacion Teresa D.. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; ArgentinaFil: Ruiz, Laura Beatriz. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Leonardi, Patricia Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; Argentin

Dieta de Pomacea canaliculata (gastropoda: ampullariidae) en su hábitat natural basada en análisis de contenidos digestivos e isótopos estables

Pomacea canaliculata es una especie nativa de la Cuenca del Río de la Plata, actualmente considerada invasora en el Sur y Este de Asia donde fue introducida con fines comerciales y se ha convertido en la principal plaga de los cultivos de arroz de la región.Realizar más investigaciones en el hábitat natural de este organismo es necesario debido a que características fundamentales de su ecología trófica permanecen aún desconocidas. El objetivo de este trabajo fue estudiar la dieta de P. canaliculata en su hábitat natural mediante los análisis de contenidos digestivos e isótopos estables de 13C y 15N. Las muestras biológicas fueron tomadas desde noviembre de 2009 hasta diciembre de 2010 en el arroyo Carnaval, un arroyo pampeano característico. Las muestras para análisis de isótopos estables y posterior aplicación de modelos de mezcla fueron colectadas en noviembre de 2011. La aplicación de un diagrama de estrategia trófica permitió establecer una dieta generalista con elevado consumo de detritos, seguidos por plantas vasculares y algas. Los resultados del modelo de mezcla, sin embargo, indicaron que la contribución relativa a la dieta de todos los recursos basales evaluados (materia orgánica particulada fina y gruesa, epipelon y macrófitas acuáticas) fue similar (aproximadamente 40 %). Estos resultados evidenciaron una fuerte plasticidad dietaria para la especie.Pomacea canaliculata is native to Rio de la Plata basin, and it is invasive in most of South and Southeast Asia after accidental introduction during unsuccessful attempts to establish commercial aquaculture of this species, and being present, the number one pest of rice crops in the region. Investigations in its native habitat are still needed because fundamental issues of its trophic ecology remain unknown. The aim of this research was to study the diet of P. canaliculata in its natural habitat through gut content techniques and stable isotopes of 13C and 15N. Biological samples were taken from November 2009 to December 2010 in Carnaval stream, a characteristic Pampean stream. Samples for stable isotopes of 13C and 15N using of a mixing model were collected in November 2011. The trophic strategy diagram evinced a generalist diet with high consumption of detritus followed by the vascular plants and algae. The mixing model results indicated that the relative contribution to the diet was similar for all basal resources: fine and coarse particulate organic matter, epipelon and aquatic macrophytes (approximately 40 %). These results evidenced a strong dietary plasticity for the species.Fil: López Van Oosterom, Maria Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Limnología "Dr. Raúl A. Ringuelet". Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Limnología; ArgentinaFil: Ocon, Carolina Silvia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Limnología "Dr. Raúl A. Ringuelet". Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Limnología; ArgentinaFil: Ferreira, Ana Clara. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Limnología "Dr. Raúl A. Ringuelet". Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Limnología; ArgentinaFil: Rodrigues Capitulo, Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Limnología "Dr. Raúl A. Ringuelet". Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Limnología; Argentin

Seasonal and regional distribution of phytoplankton in the southern Caspian Sea

Seasonal distribution of species composition, cell abundance and biomass of phytoplankton of the Caspian Sea were investigated in 2005. This survey were fulfilled in 6 transects and 26 stations A total of 260 samples were collected during winter to autumn in the southern part of Caspian Sea. Totally, 163 species of phytoplankton were identified (71 species Bacillariophyta, 31 species Chlorophyta, 27 species Cyanophyta, 21 species Pyrrophyta, and 13 species Euglenophyta). Cell abundance and biomass of Bacillariophyta were high in centre, while biomass and cell abundance of Pyrrophyta were dominant in the middle as well as parts of the Sea, respectively. The overall total average of cell abundance and biomass of phytoplankton were 56.30± 30.97 ×106cells/m3 and 221.70±75.87 mg/m3, respectively. Bacillariophyta accounted for 47% in cell abundance, and Pyrrophyta consisted of 53% of the phytoplankton biomass. Maximum phytoplankton population was recorded in winter due to Bacillariophyta and the maximum biomass in spring due to Pyrrophyta. The maximum density of Bacillariophyta was in winter and autumn while maximum biomass was observed in spring due to bigger size of Bacillariophyta such as Rhizosolenia calcar avis and Nitzschia sigmoidea followed by Pyrrophyta with high cell abundance throughout the year

Таксономическое разнообразие водорослевых сообществ р.Тетерев (Украина)

Представлены результаты исследований таксономического разнообразия фитопланктона, фитомикроэпифитона и фитомикроепилитона р.Тетерев от истока до впадения в Киевское водохранилище, включая зарегулированные участки реки и некоторые притоки