AIM To identify pathogen of diseased yellow perch and determine their virulence. METHODS AND RESULTS Fifteen Gram-negative bacterial isolates were recovered from the skin lesions of diseased yellow perch (Perca flavescens). Based on API 20NE test, ten isolates were found to share 67.2-99.9% homologies with Chryseobactertium indologenes. Based on fatty acid methyl ester analysis, 13 isolates w...

Rainbow trout (Oncorhynchus mykiss) and yellow perch (Perca flavescens) have a different sensitivity to cadmium (Cd) in vivo (trout < LC50 < perch). Metals and particularly Cd impair cortisol secretion by adrenocortical cells in both species. The purpose of the present study was to assess in vitro the effect of Cd on cortisol secretion by adrenocortical cells of trout and perch, to compare the ...

The Pneumonia Etiology Research for Child Health (PERCH) project is a 7-country, standardized, comprehensive evaluation of the etiologic agents causing severe pneumonia in children from developing countries. During previous etiology studies, between one-quarter and one-third of patients failed to yield an obvious etiology; PERCH will employ and evaluate previously unavailable innovative, more s...

In most settings, sputum is not routinely collected for microbiological diagnosis from children with lower respiratory disease. To evaluate whether it is feasible and diagnostically useful to collect sputum in the Pneumonia Etiology Research for Child Health (PERCH) study, we reviewed the literature on induced sputum procedures. Protocols for induced sputum in children were collated from publis...

Intraguild predation interactions make fish communities prone to exhibit alternative stable states with either piscivore or prey fish dominance. In the Baltic Sea, local declines of coastal piscivores like perch (Perca fluviatilis) have been observed to coincide with high densities of sticklebacks (Gasterosteus aculeatus). Mechanisms behind this shift between piscivore and stickleback dominance...

Free-living hens roost on branches in trees at night, and laying hens in aviary systems or cages provided with perches also make extensive use of these for night-time roosting. It is therefore suggested that roosting on perches is important to the hens and that domestic hens should be provided with perches in order to promote welfare. However, no study has addressed the question of motivation f...

Dwarf individuals are observed in many species of freshwater fish. This paper studies the potential causes of such stunted growth. We present a model which describes the effect of growth conditions on the ageand size-structure of fish populations. The model parameters are chosen to characterize a Eurasian perch population. Two possible causes of stunting are identified: resource limitation and ...

A wide range of factors can be attributed to the syndrome of fatty liver observed in some cultured fish species. The objective of the study was therefore to quantify different hepatocyte ultrastructural features as potentially influenced by twelve nutritional and husbandry factors, in order to discriminate the most influent factors in Eurasian perch (Perca fluviatilis), a typical carnivorous te...

Previous microsatellite analysis showed that two subpopulations of perch (Perca fluviatilis L) exist in Lake Constance. This raises questions of whether (i). Lake Constance was colonized by two populations that diverged in allopatry, or (ii). the two subpopulations diverged in sympatry. Sequence analysis of a 365 bp mtDNA fragment (5'-end of the D-loop) of perch from Lake Constance and adjacent...

ers when feeding on nectar, and this assists cross-pollination if they then visit other plants. Here we investigate the curious sterile inflorescence axis of the South African Cape endemic ‘rat’s tail’ plant (Babiana ringens, Iridaceae), whose function — unlike in other bird-pollinated plants — is exclusively to provide a perch for foraging birds. We find that this structure promotes the plant’...