1. In nature, food conditions change temporally and force consumers into trade-offs during resource allocation. In particular, under poor food conditions, for example during cyanobacterial blooms, herbivores have to optimize their resource allocation to maximize fitness, and face two decisions: (i) an individual might attempt to allocate acquired essential resources to reproductive tissues or u...

Activity of lactate dehydrogenase (LDH) was used as an effect criterion in toxicity tests with Daphnia magna. In the first part of the work, the conditions for the use of LDH activity in toxicity tests with juveniles and adults of D. magna, were optimized. The influence of parameters such as the number of animals per sample, nutritional status, age and the presence of eggs in the brood chamber ...

Adaptive evolution can occur over similar timescales as ecological processes such as community assembly, but its particular effects on community assembly and structure and their magnitude are poorly understood. In experimental evolution trials, Daphnia magna were exposed to varying environments (presence and absence of fish and artificial macrophytes) for 2 months. Then, in a common gardening e...

Alcoholic beverage is any fermented liquor such as wine, beer, or distilled spirit that contains ethyl alcohol or ethanol as intoxicating agent. Daphnia ( Daphnia magna) or water flea is a planktonic crustacean commonly found in canals and other waterways. It has been used as a standard organism for toxicity testing and toxicological reaction to environmental pollutants. The study is concerned ...

The use of in vitro (fish cell lines) is a cost-effective, very rapid, and informative tool for toxicological assessments. Using the neutral red (NR) assay, we compared acute toxicity (20hEC50) twenty-six chemical substances on rainbow trout gonad line (RTG-2) with their vivo to Barbados Millions Poecilia reticulata (48hLC50, OECD 203) crustacean Daphnia magna (48hEC50, 202). 20hEC50 values obt...

A cell-free extract of Daphnia magna was found to lyse Escherichia coli cells as shown by leakage of the enzymes alkaline phosphatase and beta-galactosidase from the bacteria. The cell-free extract was separated on Sephadex G-200, and the fractions showing an ability to lyse E. coli cels were isolated. The factor which was responsible for the lysis of the bacterial cells was probably a protein ...

Estimating parasite fitness is central to studies aiming to understand parasite evolution. Theoretical models generally use the basic reproductive rate R(0) to express fitness, yet it is very difficult to quantify R(0) empirically and experimental studies often use fitness components such as infection intensity or infectivity as substitutes. These surrogate measures may be biased in several way...

Insect resistance is the second most common trait globally in cultivated genetically modified (GM) plants. Resistance is usually obtained by introducing into the plant's genome genes from the bacterium Bacillus thuringiensis (Bt) coding for insecticidal proteins (Cry proteins or toxins) that target insect pests. The aim of this study was to examine the hypothesis that a chronic, high-dose dieta...

considering the crucial importance of daphnia species in aquaculture, in particular for artificially- cultured sturgeon fry, a comprehensive study on the hatching requirements of their diapausing eggs seemed to be inevitable in order to obtain the ideal hatching technique. to do so, the ephippial eggs were collected from live food ponds in the cultivation and breeding centre of gorgan and after...