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Renata Swiergosz 《Biometals》1998,11(2):139-143
Mercury concentrations were determined in muscles and feathers of 58 cock pheasants. Birds were collected from seven different polluted sites in southern Poland in 1987. The mercury concentrations in the muscle ranged from 0.010 to 0.026 mug g dry mass. The significantly highest values were found in muscle samples from Przylasek and Przemysl. The levels found in the flight feathers were higher than in breast feathers. Average concentrations in flight feathers ranged from 0.050 mug g (Przemysl) to 0.240 mug g dry mass (Przylasek). © Rapid Science 1998 相似文献
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Pinto RM dos Santos LC Tortelly R Menezes RC de Moraes W Juvenal JC Gomes DC 《Memórias do Instituto Oswaldo Cruz》2005,100(6):579-583
The avian eye trematode Philophthalmus lachrymosus Braun, 1902 is for the first time referred naturally occurring in a non-human mammalian host. Previously, natural infections with P. lachrymosus and other species of Philophthalmus have been occasionally reported from man, with few data on experimental infections of non-human mammals. Results presented here are related to the report of two cases of philophthalmosis due to natural infections of wild Brazilian capybaras, Hydrochaeris hydrochaeris L., 1766 with P. lachrymosus and associated pathology. Clinical signs, gross and microscopic lesions as well as new morphometric data on the parasite are presented. 相似文献
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The eye-fluke Philophthalmus gralli (Philophthalmidae Looss, 1899) was found in six birds known as great tinamous (Tinamus major) reared in a wild animal shelter located in Alajuela, Costa Rica. The birds presented conjunctival hyperemia, blepharitis, anorexia and weakness. Some of them suffered from unilateral blindness and ocular loss. After morphometric analysis, the specimens showed characteristics compatible with the digenean trematode P. gralli. The clinical signs of infection were resolved by manual removal of the adults, treatment with praziquantel and relocation into an environment without a natural water source. In order to determine if an ongoing cycle of this pathogen was present in the shelter, the habitat of the birds was inspected for the presence of infected intermediate hosts and contaminated water and objects. It was found that the snails Melanoides tuberculata acted as the intermediate host, and reared the infectious stages toward other animals, as shown by the reproduction of ocular philophthalmiasis in chickens artificially infected with excysted metacercaria. Moreover, three out of every ten snails found in the place were infected with rediae of P. gralli, raising the possibility of the dispersion of the parasite into new environments as well as the imminent zoonotic risk. The finding of P. gralli in Costa Rica is the first official report in Central America. 相似文献
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The activity rhythm of emerging grayling, Thymallus thymallus , fry was studied under semi-natural rearing conditions, using special traps buried in the gravel. Emergence was mainly diurnal with a maximum in the first hours of daylight. Fry rested at the emergence site during the daylight and moved downstream at night, particularly during the first 3 hours of darkness. These results are compared with the known activity patterns of other salmonids. 相似文献
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Rodney A. Bray 《Systematic parasitology》1996,33(2):135-141
Merlucciotrema praeclarum (Manter, 1934) is redescribed from the deep-sea benthic fishes Bathysaurus mollis, B. ferox and Cataetyx laticeps from various localities in the northern Atlantic Ocean. The genus is close to Plerurus Looss, 1907, but is retained on the basis of the presence of a muscular sinus-organ and, possibly, a rudimentary or degenerate sinus-sac. The subfamily Plerurinae Gibson & Bray, 1979 and the genus Merlucciotrema are redefined. 相似文献
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Wee Nicholas Q.-X. Crouch Kristine Cutmore Scott C. Cribb Thomas H. 《Systematic parasitology》2020,97(5):491-500
Systematic Parasitology - Prior to the present study, species of the trematode family Monorchiidae Odhner, 1911 had been reported from four of the ten families of tetraodontiform fishes: the... 相似文献
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Tormopsolus orientalis Yamaguti, 1934, is redescribed from Seriola dumerili from off Corsica, Majorca and Águilas, SE Spain. The vitellarium is interrupted at the level of the ovary and both testes, and a bipartite seminal vesicle is found in many specimens. Oral sucker papillae are always seen. Type-specimens and voucher specimens from off Japan, Bermuda, Panama, Curaçao and the Great Barrier Reef have been compared with the Mediterranean species. Specimens of T. medius Reimer, 1983, from Mozambique have been studied and this species is synonymised with T. orientalis. 相似文献
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The Eurasian Badger occurs throughout the Palaearctic, and in all states of Europe west of the border with the former Soviet Union. Within this area it is absent only from the arctic zones, high-altitude areas, and some islands. The Badger is currently a protected species in the UK, the Irish Republic, Spain, Portugal, Italy, Belgium, the Netherlands, Albania, Greece, Estonia, Luxembourg and Hungary, but Luxembourg and Hungary are to reconsider protected status. Elsewhere, the species is either considered as small-game or as a pest, hunting being regulated by closed seasons. At present Finland and Burgenland (Austria) afford protection to breeding females, whilst Bulgaria, Macedonia and the Austrian Bundesländer of Steiermark and Salzburg permit Badger hunting throughout the year. Where the species is protected, provisions usually exist for the removal or culling of ‘pest’ individuals. The official European game-bag currently totals about 118,000 Badgers, but poaching is common, particularly in the UK and Ireland. Published population estimates, coupled with national population minima obtained by extrapolation from game-bag statistics, indicate a minimum European Badger population of 1,220,000; the true figure may exceed this considerably. Badger populations appear to be either stable or increasing throughout much of Europe, although no data are currently available for the populations of Greece, Italy, Spain, Croatia, Bosnia-Hercegovina and Portugal. Badgers are uncommon in the Netherlands, Estonia, Belgium, the Slovak Republic, and possibly Poland. Only the populations of Albania and possibly of some parts of the former Yugoslavia appear to be decreasing. The Dutch population remains at considerable risk, despite modest recent increases. The population status of the endemic sub-species of Crete and Rhodes remain uncertain and require urgent clarification. A series of management recommendations are proposed to improve the status of the Badger in Europe. 相似文献
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Social organization in the pheasant (Phasianus colchicus): harem formation, mate selection and the role of mate guarding 总被引:4,自引:0,他引:4
Harem formation and mate selection were studied in the pheasant in order to determine the advantages of territorial harem defence polygyny to the two sexes. We investigated the factors affecting harem size and the advantage to a female in remaining with one territorial male during breeding.
Female group size declined during late March and early April as females moved from large overlapping ranges into smaller, more widely dispersed breeding ranges. The proportion of female groups accompanied by males increased during this period.
Some males had a disproportionate share of females. Settled females were monogamous but, because a female's nest was generally outside the male's territory, her home range was larger than his territory.
Harem members were usually from the same winter group. Harem size was not related to territory quality in terms of food supply or nesting cover. Females were loyal to one male in more than one year even if his territory position changed. Older, territory-owning males had more females, both adult and immature, than males with newly-established territories. Harem size was not correlated with territory size.
We conclude that the mating system of the pheasant is based on mate guarding which protects females not only from the risk of predation or injury, but also from excessive energy expenditure incurred through being chased by other males. When escorted by a territorial male, females spent three times as much time feeding, one-fifth as much time running, and one-tenth as much time alert, as they did when not guarded. 相似文献
Female group size declined during late March and early April as females moved from large overlapping ranges into smaller, more widely dispersed breeding ranges. The proportion of female groups accompanied by males increased during this period.
Some males had a disproportionate share of females. Settled females were monogamous but, because a female's nest was generally outside the male's territory, her home range was larger than his territory.
Harem members were usually from the same winter group. Harem size was not related to territory quality in terms of food supply or nesting cover. Females were loyal to one male in more than one year even if his territory position changed. Older, territory-owning males had more females, both adult and immature, than males with newly-established territories. Harem size was not correlated with territory size.
We conclude that the mating system of the pheasant is based on mate guarding which protects females not only from the risk of predation or injury, but also from excessive energy expenditure incurred through being chased by other males. When escorted by a territorial male, females spent three times as much time feeding, one-fifth as much time running, and one-tenth as much time alert, as they did when not guarded. 相似文献
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Populations of the colonial hydroid Obelia geniculata in the White Sea reproduce asexually by frustule formation. Young medusae appear in the plankton during July and August.
The number of medusae rarely exceeds 36 per m3, and the average number varies every year from 0.4 to 10 per m3. The size of medusae is smaller than reported from other regions. The umbrella of the largest recorded medusa was only 0.57 mm
in diameter and the specimen had just 35 tentacles. Only a few mature medusae were found during the study. The colonies in
the White Sea are epiphytic and grow only on laminarian thalli. At the beginning of July there are no colonies on thalli from
the upper subtidal zone. By the end of August, colonies of O.␣geniculata had increased in density to 30 per m2. Hydroid recruitment was attributed to active frustule production by colonies living below that zone. The frustules detach
from the stems of the hydroids and are found in plankton. Production of frustules on branches occurs continuously during colony
growth until water temperatures climb above 0 °C. We found that water temperature in this Arctic environment is generally
too low for medusa maturation and planula development in the species. Propagation by frustule formation is the principal means
of reproduction in Obelia geniculata within the White Sea, and this phenomenon accounts for the species being a dominant epiphyte on laminarian thalli there. 相似文献
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Huchen Hucho hucho from the Drina River (Serbia) revealed recently the decrease in breakpoint values for both standard length (Sl) and weight (w) in relation to the values recorded in 1999 from 110 cm to 98.4 cm and from 16.5 kg to 10.5 kg, respectively. That might
indicate to the change in certain population parameters that could have an influence to the growth in the adult period of
life. 相似文献
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N A Evans 《Journal of helminthology》1977,51(3):189-196
Two hundred roach (Rutilus rutilus) were examined over a twelve-month period to provide information concerning the occurrence of Sphaerostoma bramae. Infection levels were high during the autumn and winter and at this time of year the parasite population was composed almost exclusively of immature parasites. Maturation was rapid in the spring but was accompanied by a decrease in the infection level. In late summer, after egg-laying, losses due to the death of spent parasites began to be replaced by the recruitment of immature parasites and this recruitment reached its peak in the autumn and winter. The annual cycle of occurrence and maturation is discussed in relation to fluctuating environmental variables and the feeding behavior of the roach. 相似文献