Archive

The chaetotaxy of the anal valve of ticks of the subfamily Amblyomminae Banks, 1907 was studied by means of microscopial preparations. Fifty two species of 9 genera were studied (there are 12 genera in the fauna of the world as a whole). The critical analisys of Pomeran-tzev's classifications of the subfamily Amblyomminae (Pomerantzev, 1936, 1947, 1950) based on the chaetotaxy of anal valve only was carried out. Evolutionary series of transformation of number and topography of chaetae were established. These series have confirmed the placement of genera in 2 tribes. They were substantiated earlier (Filippova, 1993) on the basis of peculiarities of the ventral skeleton of male idiosoma and a topography of the dorso-ventral musculature attached to it. The tribe Ambliommini Banks, 1907 has the complete set of chaetae (5 pairs) and primitive (even distribution) as well as displaced topography. The tribe Rhipicephalini Banks, 1907 has a reduced number of chaetae (3 or 4 pairs) and displaced topography. The subtribe Anomalohimalaini subtr. nov. has been substantiated. A new classification of the subfamily Ambliomminae on the basis of the ventral skeleton of male, and the chaetotaxy of the anal valve of mature ticks is given.

For the first time the detailed electron microscopical investigations of sequential steps of larval-protonymphal moulting of trombiculid mite Hirsutiella zachvatkini are carefully considered. In contrast with most other arthropods the hypodermis of larvae is destroyed by necrosis during the initial steps of moulting process (12h), and so the hypodermis of quiescent regressive protonymph is built up anew from small locuses of prospective hypodermal cells. That is why, the apolysis has the atypical form. The deposition of homogeneous procuticle take place at the outer surface of apical plasma membrane plaques of short microvillus-like projections of protonymphal hypodermal cells. The epicuticle, which is composed of cement, wax and cuticulin layers, is formed quickly during the short period at the beginning of deposition of new cuticle. The newly formed hypodermis of protonymph is characterized by mitosis of its cells, which usually have no any specialized organelles, so as Golgy complexes and specific granules in apical cytoplasm. Since the ecdysis of quiescent protonymph does not occur, the end of moulting process may be marked by deposition of new cuticle in all of its components (epi- and procuticle). This process is continued up to 4 days. The old larval cuticle is retained much more than this time, and is lost quite imperceptibly in external observations. Electron microscopical peculiarities and evolutionary meaning of such type of larval-protonymphal moulting in trombiculid mites are also discussed.

The relative growth of exoskeleton organs was investigated in 19 species of ticks. Geographical isolated populations of Ixodes persulcatus, 5 species of subgenus Ixodes, 3 species of subgenus Pholeoixodes, 1 species of subgenus Scaphixodes, 1 species of subgenus Ceratixodes, 3 species of two subgenus of Hyalomma, 2 species of two subgenus of Haemaphysalis, 4 species of two subgenus of Rhipicephalus has been compared. It has been shown that the character of allometry in the populations is similar of same species and in the species of same subgenus. The character of allometry differ in the different subgenus, and the distinctions of relative growth ratio between subgenus of Ixodes are more than between different genus of Amblyomminae. Growth gradients are similar in species of same subgenus. In most species growth centres during the 1st moulting is consistent with the length of gnathosoma, of II—III segment of palps and of length of hypostome. During the 2nd moulting the growth centres in females of most species are consistent with the width of gnathosoma, of palps and of length of hypostome. In males of all species the growth centre is consistent with the width of scutum and in most species it is consistent with the width of palps. In different subgenus the growth gradients have greatest difference.

Observations were made through examination of thin blood films which were prepared at appropriate intervals from citrated fresh blood of infected birds. The comparative description of gametogenesis, zygote and ookinete formation of Haemoproteus balmorali, H. dolniki, H. majoris under the light microscope is given. The most informative signs, which can be used for haemoproteid systematics, were determined and compared with such signs of H. belopolskyi, H. fringillae, H. pallidus, H. tartakovskyi (Валькюнас, Ежова, 1993). Among them the micro-gamete length, zygote structure, morphological peculiarities of developing ookinete as well as the rate of ookinete formation can be pointed out first of all. H. pallidus microgametes are nearly twice shorter than the microgametes of other species. A large clear vacuole is formed in zygote of H. balmorali and H. fringillae only. The majority of diagnostic features have the developing ookinetes. Three types of initial stages in ookinete formation were distinguished. The first type is characteristic of Haemoproteus balmorali, H. belopolskyi, H. dolniki, H. majoris and H. tartakovskyi. Ookinete formation in these species starts with the appearance of thin long digital growth. In the course of development this growth increases in size and gives the beginning to the apical end of ookinete. The second type is characteristic of H. fringillae. In this species a short blunt growth appears in the middle part of the parasite. The growth stretches itself and the forming ookinete is put into the shape of a pear. The third type is observed in H. pallidus. Ookinete formation in H. pallidus occurs without the development of any expressed growths. In the process of transformation the ookinete of this species acquires a triangle form. One side of the "triangle" accumulates some pigment and the opposite angle becomes prolonged, thus giving the beginning of ookinete. There were clear differences between haemoproteid species on the rate of ookinete formation. The ookinetes of H. balmorali, H. belopolskyi, H. fringillae, H. majoris are formed for about 12 times more slowly than H. pallidus ones, and for about 6 times more rapidly than H. dolniki and H. tartakovskyi ones. The peculiarities of gametogenesis, zygote and ookinete formation under the stable conditions in vitro can be used as usefull additional sings for determination of haemoproteid species.

Microsporidium fluviatilis sp. n., a parasite of a fat body of Eucyclops serrulatus (Fisch.) in Russia, is described basing on light microscopic and ultrastructural characteristics. Vegetative stages were not observed in the infected cyclope. The fresh and fixed spores are permanently joined into doublets by an electron-dense substance. The monokaryotic, fresh spores are elongate pyriform, measuring 16—18 X 2.8—3.0 µm. The polaroplast has four parts together occupying about 2/3 of the spore. The two anterior parts are composed of irregular chambers: loosely arranged compartments anteriorly and closely arranged compartments posteriorly. The next polaroplast part has large ball-like compartments of the complex structure. The last, fourth polaroplast part is composed of lamellae. The thin isofilar polar filament has 23—24 coils which are arranged in one layer in the posterior third of the spore. The spore wall consists of a plasmalemma, a thin endospore and a layered exospore having fine electron-dense granular coat. There is no sporophorous vesicle or parasitophorous vacuole. The unusual polaroplast construction of Microsporidium fluviatilis sp. n. is discussed.

A cytomorphology of capsule, teguments of metasoma, presoma, thorns, proboscis hooks, a subtegumental muscles of metasoma have been studied in the cystacanthe Polymorphus magnus. An ultrastructure of tegument of cystacanthes is similar in general features to one of adult acanthocephalates; certain differences in the tegument structure of presoma are quantitative and caused by peculiarities of parasitism in final hosts. The phenomenon looking like nucleus secretion was observed in the nucleus of cells of subtegumental muscles.

Population variability of the adhesive apparatus and copulatory organ of Tetraonchus monenteron from young and adult pikes (Esox lucius) from Rybinsk reservoir (Volga river system) and adult pikes from lake Baikal has been studied. Comparison analysis of seven plastic and one meristic characters allowed to discover differences between the groups of monogeneans from young and adult pikes from "rybinsk" population by frequently of the variations of number of the tight coils of copulatory organ support bar. Differences between "rybinsk" and "baikal" populations of T. monenteron were found. The "baikal" monogeneans differ from the "rybinsk" ones by frequently of the copulatory organ phenes and also more large sizes of the chitinoid formations.

A review of Hymenolepidides from australian Marsupialia is given. These cestodes are transmitted out of the genus Hymenolepis, into which they were previously included. 3 species of them are transmitted to the genus Rodentolepis, and 7 species are arranged as a new genus Potorolepis. The diagnosis of Potorolepis and a list of species included are given. Possible phylogenetic relations of the genus Potorolepis with nearest groups of cestodes are discussed.

Some methodics and methodological problems, which could appear in earring out populationary and populationary-genetics studies of host-parasite systems, are considereded with an example of the system Digramma interrupta — bream.

A description, figures and a differential diagnosis of the new species Reniforma squamata from gills of the moon fish of north-eastern part of the Pacific Ocean are given.

The paper describes new genus Megalobenedenia and type species M. derzhavini separated from the genus Benedenia by the septate haptor. M. helicoleni (Woolcock, 1936) is the member of this genus too.

Summary is absent.