摘要:

AbstractThirty‐five species of protozoan parasites belonging to thirteen genera have now been recorded for British small rodents. These include species ofEntamoeba, Giardia, Spironucleus, Trichomonas, Chilomastix, EimeriaandCryptosporidiumin the gut;Trypanosoma, HepatozoonandBabesiain the blood; andToxoplasma, FrenkeliaandSarcocystisin the tissues. Recent advances have progressed along two lines, the elucidation of the life‐cycles of the species ofFrenkeliaandSarcocystis, which are now known to involve a carnivore as the final host, and laboratory studies on those parasites that can be maintained in laboratory animals. It is now possible to draw up a definitive list of hosts and parasites and this should serve as a basis for studies on the epidemiology of these parasites and their possible effects on their ho

ISSN:0305-1838    

DOI:10.1111/j.1365-2907.1987.tb00048.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractLittle is known of the biology of the majority of microparasites except for those of medical or veterinary importance. It is suggested that techniques already developed for identification and quantification of these important parasites should be modified as necessary and extended to the study of other microparasites. Isolation and maintenance of microparasites in laboratory‐maintained hosts will improve these diagnostic techniques and will also allow investigation of the biology of the parasites under controlled conditions. The value of laboratory‐based experiments as an adjunct to ecological studies is emphasized. Problems of interpretation are indica

ISSN:0305-1838    

DOI:10.1111/j.1365-2907.1987.tb00049.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

ISSN:0305-1838    

DOI:10.1111/j.1365-2907.1987.tb00050.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractBloodfilms were collected from 491 bats representing 12 of the 15 species of British bats, from a number of sites in England and Scotland, and examined for haematozoa.Trypanosoma (Schizotrypanum) sp. were found inPipistrelluspipistrellus, Nyctalus noctula, N. leisleri, Eptesicus serotinusandMyotis brandtii, andTrypanosoma (Megatrypanum) incertumwas found inP. pipistrellus.Both subgenera of trypanosomes appear to be transmitted by the bat bugCimex pipistrelli.Gametocytes of the haemoproteidPoly‐chromophilus murinuswere found in one‐third ofMyotis daubentoniiexamined, and stages of the parasite were found in the vector, the wingless blood‐sucking fly,Nycteribia kolenatii, collected from these bats. The piroplasmBabesia vesperuginiswas found in the blood ofP. pipistrellusandMyotis mystacinus, and was the only parasite to show evidence of pathogenicity to

ISSN:0305-1838    

DOI:10.1111/j.1365-2907.1987.tb00051.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractField and laboratory studies on the helminths of rodents have mainly involved direct life‐cycle nematodes (of the super families Rhabditoidea, Oxyuroidea, Trichuroidea and Trichostrongyloidea) and, to a lesser extent, indirect life‐cycle cyclophyllidean cestodes (of the families Catenotaeniidae and Hymenolepididae). In insectivores on the other hand, because of their different feeding habits, the composition of the helminth fauna largely comprises hymenolepid and dilepidid cestodes together with brachylaemid and dicrocoeliid digeneans, the life cycles of which are little known. The value of further studies on the biogeography of helminths of rodents and insectivores in the British Isles is emphasized. The role of rodent nematodes as laboratory models for chemotherapy is also discus

ISSN:0305-1838    

DOI:10.1111/j.1365-2907.1987.tb00052.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

ISSN:0305-1838    

DOI:10.1111/j.1365-2907.1987.tb00053.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractThis paper reviews the host‐helminth interactions that are of importance in regulating both the abundance of helminth parasites of rodents and the host population abundance. Parasite density has an effect on the ability of individual parasites to grow, reproduce and survive within the definitive host, and it also influences the ability of the infected host to survive and reproduce. The severity of the impact of such density‐dependent responses is related to the pattern of parasite distribution within the host population. The potential of helminth parasites to regulate the abundance of a small mammal population is illustrated using an experimental example. Areas identified for further research include (i) an investigation of the relative importance of parasite density‐dependent effects on parasite and host survival and reproduction for specific host‐helminth associations; (ii) more research into the impact of helminth density on host reproduction; and (iii) research into the impact of helminths on the population dynamics of small mammal populations using field and laboratory experiments designed to assess the relative importance of helminths in regulating the abundance of their host populations.SummaryIn this paper we have considered parasite density as an important determinant of parasite and host population dynamics. Because the relative impact of density on different population processes will differ for different helminths, researchers interested in accounting for temporal dynamics of a specific parasite will need to investigate the density‐dependent processes involved in the life cycle of that helminth.Although interactions between the population biology of both the host and helminth parasite are of fundamental importance to the population dynamics of the parasite, they also are important in determining the population dynamics of the infected host population. Because helminths, by definition, must have an impact on the ability of the host population to survive or reproduce they, therefore, also have the potential to regulate the abundance of the host population (Anderson&May, 1978; Anderson, 1979). More research is needed on the effect of parasite density on the rate of reproduction of infected hosts. Finally, given recent theoretical and experimental evidence that parasites can regulate mammal populations, much work is needed to determine conditions when this actually occurs in

ISSN:0305-1838    

DOI:10.1111/j.1365-2907.1987.tb00054.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

ISSN:0305-1838    

DOI:10.1111/j.1365-2907.1987.tb00055.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractA review of field data indicates the ubiquitous occurrence of parasites in small mammal communities, with the heligmosome nematodes in many cases dominant members of the helminth fauna. The population dynamics of the heligmosomes are discussed in relation to the interpretation of patterns of infection observed in the field. Laboratory data are then used to indicate ways in which the parasites might reflect or influence the population biology of their hosts. The aim of the paper is to suggest the potential significance of parasitism for the ecology of small mammal populations.

ISSN:0305-1838    

DOI:10.1111/j.1365-2907.1987.tb00056.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractChanges have been observed in the biology of protozoan and helminth parasites of small mammals during a variety of experimental nutritional manipulations ranging from deficiency in a specific nutrient to the general withholding of food from the host. Commonly observed effects include retardations in parasite growth rate, gametogenesis, fecundity, and asexual multiplication. The duration of patency and of the association of a parasite with its host have also been observed to be curtailed. The nutritional responses of parasites during host hibernation require investigation and much research will be needed to explain how perturbations in host dietary composition and intake may lead to the observed effects. Care should be exercised over applying the results from experimental studies to naturally occurring infections, but the experiments are justified because they indicate potential effects, if not their biological significance, and because causation can be determined.

ISSN:0305-1838    

DOI:10.1111/j.1365-2907.1987.tb00057.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY