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The distribution of Proteocephalus exiguus in the gut of vendance was examined with regard to the age of parasites and infrapopulation density in individual hosts. The tapeworms can occupy the whole length of the intestine, but they are most abundant in its middle and posterior parts. The distribution of four age classes changed in relation to the infrapopulation density. In higher densities young specimens prevailed in the anterior part of the intestine, while the gravid ones were in its posterior part. The possible reasons of such an „age segregation" are discussed.
This work consisted in studying the frequency of deformations of the attachment organ in specimens representing the family Diplozoidae, occurring in roach, common bream, and white bream from live different water bodies. These water bodies differed in morphometric parameters, levels of eutrophication, and character of their pollution. The presence of three types of deformation was stated. The most common were deformations of type II (morphological changes of clamps, such as sclerite deformation, incomplete sclerite separation or sclerites missing altogether in a clamp), while less frequent were those of types I (chaoges in the size of clamps not associated with the structural changes) and III (missing clamps in a set). Most frequently anomalies of the attachment organ were stated in polluted Łyna River, polluted Wulpińskie Lake, and in dystrophic Warniak Lake. Less frequent were anomalies in less eutrophied lakes Dgał Wielki and Ukiel. Also the prevalence values of those parasites were the highest in the polluted water bodies. The present study suppons believes of other authors, that both infection parameters of Diplozoidae affecting fishes and deformations of monogeneans' attachment apparatus can be treated as indicators of environmental pollution.
The parasites of bream from the reclaimed Lake Kortowskie were comprised of 16 species belonging to Protozoa, Monogenea, Digenea, Cestoda, Acanthocephala, Nematoda, Crustacea and Molusca. Some parasites were found only on single host specimens (Trichodina sp., Gyrodactylus sp., Ichthyocotylurus platycephalus met., Glochidium larj. The other species (Dactylogyrus auriculatus, Phyllodistomum elongatum, Acanthocephalus lucii, Philometra sp.) occurred rarely and with low intensity. A comparative study of the infestation of bream from Lake Kortowskie in the 1984-1994 period indicated that while the number species in the parasite community remained unchanged (16 species), the set of parasites differed distinctly (seven species disappeared and seven others appeared). The frequency of four species, E. sieboldi, Myxobolus sp., Trichodina sp. and Philometra sp., decreased, that of Tylodelphys clavata increased, while four others, Gyrodactylus sp., Diplostomum sp., Caryophyllaeus laticeps, Glochidium lar., occurred at the same level.
The aim of the study was to determine leeches found on the lake fishes. From the lake Ukiel, 213 roaches (R. rutilus) and from the lake Wulpińskie 202 were examined between Nov. 1988 and Dec. 1999. From the Warniak 258 roaches and 9 tenches (Tinca tinca) were examined between May 1998 and Nov. 1999. Warniak on roach (R. rutilus) 4 Piscicola geometra and Hemiclepis marginata on the fish body were found, tench (Tinca tinca) P. geometra were found on gills. Ukiel on roach Piscicola pojmanskae on gills were found. Wulpińskie on roach P. pojmanskae and Piscicola sp. as well as 2 Caspiobdella fadejewi on gills were found. Prevalence and intensity of fish infection with leeches was low in all lakes. C. fadejewi and P. pojmanskae are the first recorded on the lake fishes. Further investigations are necessary since they can result in informations conceming inhabitation of new microhabitants with P. geometra gills.
A parasitological study of 68 fishes belonging to seven species was conducted in July 2009. The fish species included the following: bleak, Alburnus alburmus (L.); roach, Rutilus rutilus (L.); rudd, Scardinius erythrophthalmus (L.); bream, Abramis brama (L.); ruffe, Gymnocephalus cernuus (L.); bullhead, Abramis bjoerkna (L.); gudgeon, Gobio gobio (L.). The aim of the study was to analyze the parasites of fish from Lake Wymój. A total of 16 parasites species belonging to the following taxa were identified: Monogenea (Dactylogyrus minor, Gyrodactylus sp., Paradipiozoon homoion homoion), Digenea (Diplostomum sp., Ichthyocotylurus platycephalus, Posthodiplostomum cuticola, Rhipidocotyle sp., Tylodelphys clavata), Cestoda (Caryophyllaceus laticeps, Paradilepis scolecina, Protocephalus sp.), Nematoda (Camallanus lacustris), Crustacea (Argulus foliaceus, Caligus lacutris, Ergasilus sieboldi), Mollusca (glochidia). Of all the parasites collected, the most frequent group was the metacercaria Diplostomum sp., the pleurocercus Paradilepis scolecina occurred less frequently, and the rest of the parasite species occurred rarely.
The studies were carried out during the period April 1982 - July 1984. The statistical analysis of the dependence between the temperature and the intensity of occurrence of 4 species of the genus Dactylogyrus in bream (Abramis brama L.) was made in two variants (tab. 1, 2). In both cascs correlation coefficients between the variables, as well as regression coefficients, estimating the linear dependence according to the equation: y = a±bx (cf. fig. 1a-d). The correlation coefficient was verified using the t Student test. The statistical analysis has not revealed any statistically significant dependence between mean month temperatures during the whole investigation period, and the intensity of occurrence of particular of the genus Dactylogyrus species. However, a highly significant (+ +) and significant (+) correlation has been found between the temperature differences in consecutive months of investigations, and the intensity of occurrence of particular species. This confirms the previous suggestion that the studied species of the genus Dactylogyrus react to the temperature changes in the environment. In agreement with calculated coefficients, the higher the temperature difference within a short period, the greater the changes of the density in the population. The density of all the species was the highest in March when the temperature increased by ca. 4°C within a month, and the lowest in October or November at the temperature decrease by ca. 4.5°C. It can be assumed that a rapid temperature increase enhances the reproductive activity of the parasites and their expansion to the hosts, white a rapid decrease inhibits their reproduction and possibly increases also the mortality of adult individuals.
During the parasitological studies in Dgał Wielki Lake 32 specimens of Trichodina pediculus were collected from roaches (Rutilus rutilus). T. pediculus were subjected to the metric and meristic measurements. High correlation factors significance was obtained between the following data: body diameter and adhesive disc diameter with border membrane, adhesive disc diameter without border membrane, denticulate ring diameter, height of denticle. However no correlation significance between body diameter and number of denticles was found.
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