Search results for "perch"
showing 10 items of 1084 documents
Ergasilid copepods as parasites of perch Perca fluviatilis and roach Rutilus rutilus in Central Finland: seasonality, maturity and environmental infl…
1992
A total of 1255 roach Rutilus rutilus (L.) and 866 perch Perca fluviatilis (L.) from four interconnected lakes in Central Finland differing in trophic status and pollution level were studied for parasitic ergasilid copepods between August 1985 and December 1988. In addition, 109 whitefish (Coregonus sp.) were studied from one of the lakes. Four ergasilid species were found: (the prevalence and intensity/fish, respectively, for the whole material are given in parentheses) Ergasilus briani (16·9%, 0·5), Neoergasilus japonicus (15·6%, 0·4) and Paraergasilus longidigitus (2·1%, 0·02) on the roach and Ergasilus sieboldi (9·9%, 0·1) and P. longidigitus (4·9%, 0·05) on the perch. Logit analysis wa…
Gastric evacuation rate of burbot fed single-fish meals at different temperatures
1997
The gastric evacuation rates of burbot Lota lota, fed a single meal of vendace, Coregonus albula, were measured in the laboratory at five temperatures (1·3, 2·6, 4·8, 9·4 and 12·6° C). Gastric evacuation rate increased exponentially with increasing temperatrure, but the results suggest that gastric evacuation rates of burbot at low temperatures are lower than those of other freshwater fish species. Temperature and the ratio of meal weight to burbot weight were the most important factors affecting gastric evacuation rate. There was no significant difference in gastric evacuation rate between three different prey species: vendace, perch Perca fluviatilis, and smelt Osmerus eperlanus.
Occurrence and pathogenicity of Yersinia ruckeri at fish farms in northern and central Finland
1992
. Salmonid fish at fish farms in northern and central Finland and perch, Perca fluviatilis L., roach, Rutilus rutilus (L.), and whitefish, Coregonus sp., from four lakes in central Finland were studied between 1985 and 1990 for the occurrence of Yersinia ruckeri. The bacteria were found in fish from both areas, but in most cases, only single diseased salmon, Salmo salar L., brown trout, S. trutta L., rainbow trout, Oncorhynchus mykiss (Walbaum), whitefish and perch were encountered and were always connected with stress conditions. One clinical outbreak occured in salmon fingerlings in northern Finland, and the fish were successfully treated with trimethoprim-sulpha. Monthly monitoring of la…
Temperature effects on anaesthesia with clove oil in six temperate-zone fishes
2004
The potential use of clove oil (eugenol) as an anaesthetic for Atlantic salmon Salmo salar, brown trout Salmo trutta, rainbow trout Oncohynchus mykiss, whitefish Coregonus lavaretus, perch Perca fluviatilis and roach Rutilus rutilus was examined at 5, 10, 15 and 20°C using three anaesthetic concentrations (varying from 20 to 200 mg l -1 ) at each temperature. Substantial species differences in sensitivity to clove oil were observed, even amongst congeners, and there may be some disadvantages (slow recovery and possibly mortality) with using clove oil for 0+ year whitefish and at low temperatures for perch and roach.
Reproductive, biochemical, physiological, and population responses in perch (Perca fluviatilisL.) and roach (Rutilus rutilusL.) downstream of two ele…
2001
Perch (Perca fluviatilis L.) and roach (Rutilus rutilus L.) populations in a state of late vitellogenesis were studied downstream of two pulp and paper mills and at upstream references in southern Lake Saimaa, Finland. The mills used elemental chlorine-free bleaching and activated sludge effluent treatment technologies. The exposure of fish to pulp mill effluents, as measured by concentrations of chlorophenolics in the bile and liver ethoxyresorufin-O-deethylase (EROD) activity, was low and almost similar to the references. Nevertheless, bile resin acid concentrations in exposed perch and roach (260-320 micrograms/ml) and bile beta-sitosterol concentrations in exposed roach (1.5-3.5 microgr…
Morphological variation of perchPerca fluviatilisin humic lakes: the effect of predator density, competition and prey abundance
2010
Between and within-lake variations in morphology of perch Perca fluviatilis were studied in four humic lakes in eastern Finland. Perca fluviatilis were more streamlined and smaller headed in a lake with the highest abundance of cyprinids, but lowest abundance of predators (Lake Tuopanjarvi), indicating adaptation to planktivorous feeding and low predator density. Highest bodied fish were found from a lake with the lowest cyprinid but highest predator abundance (Lake Koppelojarvi), which conversely indicates adaptation to more effective predator avoidance. Furthermore, the length of the paired fins was longest in Lake Kinnasjarvi and Lake Tuopanjarvi, where the abundance of benthic macroinve…
Diet composition and seasonal feeding patterns of a freshwater ringed seal (Pusa hispida saimensis)
2014
The Saimaa ringed seal (Pusa hispida saimensis) is one of the few freshwater seal populations worldwide. The major conservation issue of this critically endangered population is bycatch mortality. We used digestive tract content and stable isotopes (d 13 Ca ndd 15 N) to estimate the diet and seasonal feeding patterns for gaining better understanding of the seals feeding habits and potential conservation implications. The diet was similar across age groups. Altogether 15 fish species were identified and the most important were smelt (Osmerus eperlanus), ruff (Gymnocephalus cernuus), perch (Perca fluviatilis), vendace (Coregonus albula )a nd cyprinids. The high d 15 N values suggested that th…
Complex formation of Tb3+ with glycolate, D-gluconate and α-isosaccharinate in neutral aqueous perchlorate solutions
2003
Summary An electromigration technique was used for measurements of metal-ligand formation constants of non-carrier-free 160Tb3+ with glycolate, D-gluconate and α-isosaccharinate ligands. The overall ion mobilities of Tb at different concentrations of the ligands were measured in chemically inert perchlorate solutions (pH 7 and T= 298.1K) with an overall ionic strength μ = 0.1. The stepwise stoichiometric stability constants are: Tb3+/glycolate: log K 1=2.72(18), log K 2=1.73(19), log K 3= 1.12(17), Tb3+/D-gluconate: log K 1=2.96(11), log K 2=2.60(11), log K 3=1.13(9), Tb3+/α-ISA: log K 1=3.07(8), log K 2 = 2.69(11), log K 3 = 1.80(12).
Corrigendum to “Polyvascular subclinical atherosclerosis in familial hypercholesterolemia: The role of cholesterol burden and gender” [Nutr Metab Car…
2019
International audience; Background and aim: Heterozygous familial hypercholesterolemia (HeFH) is a genetic disease characterized by a heterogeneous phenotype. The assessment of cardiovascular (CV) risk is challenging for HeFH. Cholesterol burden (CB) allows to estimate the lifelong exposure to high levels of cholesterol. The aim of this study was to analyze the distribution of subclinical athero-sclerosis and the relationship between atherosclerosis and the CB in a sample of HeFH patients, focusing on sex-related differences. Methods and Results: 154 asymptomatic HeFH subjects underwent coronary-artery-calcium score (CACs) and Doppler ultrasound of carotid and femoral arteries. Yearly lipid…
Innovations in endodontic filling materials
2012
One of the goals of endodontic treatment is to achieve a complete, tridimensional, hermetic sealing of the root canal system to prevent the entry of microorganisms or their products through both the coronal and apical pathways. Gutta-percha is the most widely used material for root canal filling and despite its numerous properties, such as biocompatibility and thermoplasticity, it has however an important limit: the lack of adhesion to the canal walls. Attempts to address this problem have been made over the years by using endodontic cements capable of bonding to canal dentine but their tendency to resorption in time can compromise the quality of treatment. The first step towards a real adh…