|
Феномен филогенетической сингоспитальности у акариформных клещей (Acari: Acariformes) — постоянных паразитов позвоночных. С. 81-100.
Рассмотрены все наиболее значимые случаи сингоспитальности у акариформных клещей-постоянных эктопаразитов позвоночных, в которых несколько моноксенных видов паразитов образуют монофилетическую группу, возникшую в пределах вида хозяина. Дан анализ причин возникновения этого феномена, для которого введен специальный термин — «филогенетическая сингоспитальность» (ФС). Показано, что основными условиями возникновения феномена ФС могут выступать 2 независимых фактора или их комбинация: 1) сложный дизъюнктивный ареал хозяина, приводящий к аллопатрическому видообразованию у паразитирующих на нем клещей; 2) глубокая специализация клещей к обитанию на локальных участках тела хозяина, ведущая к симпатрическому (синксеническому) видообразованию.
in English
Bochkov A.V., Mironov S.V.
The phenomenon of phylogenetic synhospitality in acariform mites (Acari: Acariformes) — the permanent parasites of vertebrates. P. 81-100.
The term synhospitality means the association of two or more closely related parasite species with one host species (Eichler, 1966). The cases of two or three synhospitalic species are known from the same host species, and especially ones where parasites were recorded from different parts of the host range, are quite common. The most ordinary reason causing synhospitality in permanent parasites is the host switching. Nevertheless, there are a number of synhospitality cases, where the parasite complex is monophyletic because evolved on a single host species. The special term — "phylogenetic synhospitality" (FS) is proposed for these cases of synhospitality.
Most known cases of FS in acariform mites, permanent parasites of vertebrates, are analysed. It is found out that both astigmatan and prostigmatan parasite mites demonstrate a numbers of FS. The majority of these examples represent parasitism of two or three synhospitalic parasite species. Impressive examples of FS involving a number of synhospitalic species is shown by only astigmatan mites inhabiting the fur of mammals or plumage of birds. Most known examples involving four or more mite species are discussed: 51 mite species of the genus Schizocarpus (Chirodiscidae) parasitizing Castor fiber and C. canadensis (Castoridae); 6 species of Listrophorus spp. (Listrophoridae) from Ondatra zibethicus (Cricetidae); 23 species of Listrophoroides s. l. (Atopomelidae) from Maxomys surifer (Muridae); 21 species of Cytostethum (Atomelidae) from Potorous tridactylus (Potoridae); 4 species of Listrophoroides (Afrolistrophoroides) from Malacomys longipes (Muridae); 7 species of Fainalges (Xolalgidae) from Aratinga holochlora (Psittacidae); 4 species of Zygepigynia (Pteronyssidae) from Chrysocolaptes lucidus (Picidae).
The main reason of FS is that, in spite of the Fahrenholz's rule, the speciation of many parasites proceeds much more intensively than in their hosts because of the more rapid replacement of the parasitic generations.
The first factor causing FS is the mite speciation it temporary segregated populations of the host (allopatric speciation). In this case, the "multi-species complexes" appeared after the subsequent reintegration of the host populations formerly isolated. The second factor is the speciation due to the specialization of mites to local microhabitats in the fur or plumage of host (sympatric or synxenic speciation). The second way of speciation is most characteristic for mites with highly specialized attaching structures.
The phenomenon of FS more resides in ectoparasites of mammals rather than in feather mites in spite of much more structural complicacy of plumage rather than the fur. The high mobility of birds and wide dispersion of their new generations probably embarrass the process of sympatric speciation in their parasites. As a rule, only really significant geographical barriers play role for population isolation in birds.
Thus, it could be concluded that two independent factors or their combination lead to FS. (i) The complex and/or disjunctive host range giving a possibility for allopatric speciation in parasites, (ii) The deep mite specialization to local microhabitats on the host body causing sympatric (synxenic) speciation. Fur of mammals and plumage of birds are very complicated in structure and microconditions and provide a considerable number of different microhabitats for mites inhabiting them.
The prevalence of one of these two factors depends on the biological peculiarities of both parasites and their hosts. In mites with lesser specialized attaching organs, for example in atopomelids, allopatric speciation dominates. In mites with strongly specialized attaching organs, for example in listrophorids or chirodiscids, both pathways of speciation may take place. In feather mites, sympatric speciation should be more probable due to quite complicate and various structure of feathers in avian hosts. In fur mites, sympatric speciation is more likely in mites parasitizing hosts with peculiar ecology, for example in semiaquatic rodents possessing quite different fur structure in different parts of the body.
Зависимость структуры компонентных сообществ паразитов от возраста хозяина. С. 101-113.
На примере сообществ паразитов гольяна и хариуса из бассейнов рек Северная Двина и Печора показано, что паразитарные сообщества с младших возрастных групп хозяев отличаются от таковых с рыб старшего возраста меньшим количеством особей и биомассы паразитов, числа их групп, выделенных по соотношению биомасс, часто меньшим набором видов. Значения же индексов видового разнообразия, описывающих сообщества паразитов от хозяина разного возраста в пределах участка сбора материала, почти всегда одинаковы. Это наблюдение требует проверки, так как у сообществ паразитов хариуса разного возраста из р. Пинега и гольяна из р. Човью (Доровских, 2002) величины индексов, характеризующих паразитарные сообщества разновозрастных рыб, различны.
in English
Dorovskikh G.N., Stepanov V.G.
Dependence of the structure of component parasite
communities on host age. P. 101-113.
Dependence of the structure of component parasite communities on host age is studied by the example of parasite communities in minnow and grayling from the North Dvina and Pechora rivers basins. Parasite communities from immature host groups are revealed to be different from those in mature fishes by lesser number of parasite individuals and biomass, number of groups discriminated by the ratio of biomasses, and frequently by lesser number of species. Indices of diversity describing parasite communities from hosts of different ages are nearly always the same in the area examined. This observation needs in verification because values of the indices characterizing parasite communities from fishes of different ages are not equal in the parasite communities from grayling of different age from the Pinega river and minnow from the Chovju river (Dorovskikh, 2002).
Таксономическое разнообразие паразитов бесчелюстных и рыб бассейна Волги. V. Нематоды (Nematoda) и волосатики (Gordiacea). С. 114-128.
Приводится список нематод и волосатиков рыб бассейна р. Волги с указанием хозяев и распространением в различных районах бассейна. Приведены данные по нематодам 51 вида рыб. Список включает 39 видов и 11 не определенных до вида форм нематод. У 5 видов рыб найдены личинки волосатика Gordius sp. Sinoichthyonema amuri занесена в бассейн р. Волги случайно в процессе интродукции амурских видов рыб.
in English
Zhokhov A.E., Molodozhnikova N.M.
Taxonomic diversity of parasites in agnathans
and fishes from the Volga River basin. V. Nematoda and Gordiacea. P. 114-128.
The checklist of Nematoda and Gordiacea parasitizing agnathans and fishes in the Volga River basin is presented. Hosts and areas of distribution are indicated for each parasite species. The checklist includes 39 species and 11 nonidentified larval forms of nematodes from 51 fish species. Larvae of Gordius sp. are found in 5 fish species. The nemadote species Sinoichthyonema amuri have been introduced into the Volga basin occasionally during the process on introduction of fish species from Amur River.
Взаимодействие Steinernema carpocapsae с фауной членистоногих и природными опуляциями энтомопатогенных нематод в биотопе плодового сада. С. 129-138.
Изучено влияние нематод S. carpocapsae штамм «agriotos» (Rhabditida: Steinernematidae) на численность членистоногих плодового сада, а также получены данные об особенностях экологии природных популяций энтомопатогенных нематод в присутствии нового для данного биотопа вида этих паразитов. При внесении нового вида нематод в дозе 500 тыс. инвазионных личинок на 1 м2 поверхности почвы наблюдается максимальное снижение (до 50%) общей численности насекомых фитофагов на обработанном участке, при этом не установлено отрицательного воздействия нематод на полезных членистоногих. Увеличение и уменьшение дозы нематод ведет к повышению численности фитофагов. Снижение эффективности воздействия нематод на численность вредных насекомых с увеличением дозы внесения инвазионных личинок указывает на существование регуляторных механизмов, определяющих оптимальные соотношения численности этих паразитов на микро- и макропопуляционных уровнях. Внесение нового для данного биотопа вида энтомопатогенных нематод сопровождается заметной активизацией природных популяций энтомопатогенных нематод в поверхностном слое почвы.
in English
Danilov L. G., Makhotkin A.G., Vasiliev S.V., Turitsyn V.S.
Interaction between Steinernema carpocapsae with the Arthropode fauna and natural populations of entomopathigenic nematodes in orchard biotope. P. 129-138.
The introduction of a novel entomopathogenis nematode Steinernema carpocapsae strain «agriotos» (Rhabditida: Steinernematidae) into the soil of an orchard resulted in the reduction (up to 50%) of total amount of phytophagous insects. No negative effect on the groups of beneficial arthropods, caused by the nematode, has been found. Recommended optimal application rate is 500 thousand invasive nematode larvae per 1 m2 of the soil. Increase or decrease of the application rate resulted in the rise of the abundance of phytophagous insects. This fact proved the existence of regulating factors determining optimal ratios of the amounts of parasites at micro- and macro-levels. Activation of native populations of entomopathogenic nematodes in soil surface layer has been observed after the introduction of the novel parasite species.
Экология и эпизоотология микроспоридий малярийных комаров (Diptera: Culicidae) юга Западной Сибири. С. 139-150.
Изучены сезонное и многолетнее распространение микроспоридий в природных популяциях малярийных комаров. Описаны симптомы, хозяинная специфичность микроспоридий и локализация паразита в тканях хозяина.
in English
Simakova A.V., Pankova T.F.
Ecology and epizootology of Microsporidia in malarial mosquitoes (Diptera: Culicidae) from the South of Western Siberia. P. 139-150.
The ecology and epizootology of Microsporidia were studied in the natural population of malarial mosquitoes from Western Siberia over a 30-year period. Symptoms of the disease, host specificity and character of parasite localization in host tissues were investigated. Microsporidia of 9 species from 4 genera, namely Amblyospora, Crepidulospora, Senoma, and Parathelohania, were found in the malarial mosquito larvae from the territory examined. The mosquito species Anopheles messeae was infested by larger number of the microsporidian species, than A. beklemishevi.
Spores and active stages of the microsporidian Senoma sp. from mosquito larvae are localized in epithelial cells of the host's intestine. There are no external signs of the infestation. The infested larvae do not die, and the infection proceeds to the pupal stage. Microsporidians of the genus Parathelohania infest larvae of both male and female mosquitoes. The parasites localized in the fat body cells. Body of the infested host gets an opaque white color in the period of spore maturation. The infested larvae perish at 4th stage.
Microsporidian spores are formed in the mosquito larvae of both sexes. However, infection rate is much higher in the male larvae (77.8%), than that in the female larvae (22.2%). Symptoms of the disease under the infestation by the genera Crepidulospora and Amblyospora are similar to those under the infestation by Parathelohania sp. There are no external signs of the infestation in the adult mosquito females. In these hosts microsporidians form large two-nuclear spores with a thin capsule accounted for transovarial transmission. An about two times decrease of fertility in the Anopheles messeae females infested by the Parathelohania microsporidians is revealed. Mean number of eggs laid by the infested females was 121, while that of the noninfested ones was 232. Thus, the cause of the decrease in the mosquito abundance is both the elimination of male larvae and the decrease of fertility in females.
In Siberia malarial mosquitoes yield 2 or 3 generations per year. Infested larvae are rarely occurred in the beginning of summer. Maximal extensiveness of the invasion may be observed in the end of summer, because of the accumulation of the infection in water bodies. Number of the peaks of infestation coincides with the peaks of abundance of mosquito larvae of 4th stage. Peaks of infestation are delayed as compared with the peaks of mosquito abundance. It is an evidence of the development delay in the infested larvae.
Long-term dynamics of the infestation by microsporidians is studied. The epizooty caused by Parathelohania was observed in the malarial mosquitoes in the eighties (with the infestation rate up to 62%). In the last ten years the infestation rate was low (from 0.1 to 2.6%).
Зональные особенности фауны трематод гусеобразных птиц европейского Северо-Востока России. С. 151-158.
Исследовано и проанализировано зональное разнообразие трематод гусеобразных птиц региона. Показан характер изменения разнообразия, обилия, структуры и распределения трематод птиц по подзонам тундры и лесной зоны региона. Установлено закономерное снижение общего обилия трематод с севера на юг.
in English
Jushkov V.F.
Zonal peculiarities of the nematode fauna in Anseriformes from the
North-East of European Russia. P. 151-158.
Zonal diversity of trematodes from anseriform birds in the North-East of the European part of Russia is investigated and analyzed. Characteristics of the differences in the diversity, abundance, faunistic structure, and distribution of the bird-infesting trematodes between the tundra subzones and forest zone of the studied region are shown. Regular southward decrease of the total abundance of trematodes in birds is recorded.
Павел Абрамович Чиров. С. 159-161.
Реферат отсутствует.
in English
----------
Obituary 1. P. 159-161.
Summary is absent.
Иван Семенович Худяков. С. 162-164.
Реферат отсутствует.
in English
----------
Obituary 2. P. 161-164.
Summary is absent.
|
|