I measured physico-chemical properties and phytoplankton in the small, shallow tropical reservoir of Oyun (Offa, Nigeria) between January 2002 and December 2003. I identified 25 phytoplankton genera in three sampling stations. Bacillariophyceae dominated (75.3%), followed by Chlorophyceae (12.2%), Cyanobacteria (11.1%) and Desmidiaceae (0.73%). The high amount of nutrients (e.g. nitrate, phosph...

The rare boreo-alpine, oligotraphenic diatom Planothidium distinctum (= Achnanthes distincta) was first described from the western Alps in 1954. Achnanthes hirta, a species described in 1970 from the Pyrenees, is regarded as a heterotypic synonym of Planothidium distinctum but almost all morphological details of P. distinctum are known from the type material of Achnanthes hirta. On the basis of...

The diatom family Rhaphoneidaceae is characterized by high generic diversity and low species diversity with most genera known to have long stratigraphic ranges. The genera within this family are neritic marine, and mostly epipsammic. A new modern and epipsammic genus, Meloneis gen. nov., is described herein and is compared to all genera within Rhaphoneidaceae and especially to Rhaphoneis Ehrenb...

Studies on the plankton communities and physico-chemical characteristics of Elechi Creek were carried out for six months, from January to June. Fourteen parameters evaluated, monthly alteration was investigated. Water quality samples analyses obtained simultaneously. temperature in range (29.4–35.5⁰C) across (3) study locations. The results revealed no spatial dissimilarity (P˃0.05) all physico...

A new Gomphosphenia species (Bacillariophyceae) was found during a diatom survey in the “Réserve Naturelle Nationale de la Vallée Chaudefour” (RNN VC), Massif Central (France). vallei sp. nov. is described from stone surfaces Pérouse Stream, Auvergne, France. detailed description of morphology G. presented, based on light and scanning electron microscopy. This small-sized characterized by linea...

Tropical shrimp aquaculture systems in New Caledonia regularly face major crises resulting from outbreaks of Vibrio infections. Ponds are highly dynamic and challenging environments and display a wide range of trophic conditions. In farms affected by vibriosis, phytoplankton biomass and composition are highly variable. These conditions may promote the development of harmful algae increasing shr...

A hydrobiological study conducted in nine different ponds of a rural area of Barak Valley, Assam, showed that the concentrations of chemical parameters like dissolved oxygen, free carbon dioxide, pH, conductivity alkalinity nitrate, phosphate, calcium, magnesium, copper and zinc are within the permissible levels of drinking water quality standard of WHO and ISI. However iron content was higher ...