scholarly journals Morphobiological characteristics of trematode cercariae of the families Opisthorchiidae and Notocotylidae

2020 ◽  
Vol 49 (6) ◽  
pp. 71-78
Author(s):  
О. M. Bonina ◽  
Е. А. Serbina

The results of studying the body structure of trematode cercariae of the families Opisthorchiidae and Notocotylidae and the features of their development in Western Siberia are presented. The data of long-term (1994–2019) studies on the spread of these pathogens of dangerous parasitic diseases in humans and animals are analyzed and summarized. The studies were conducted according to generally accepted methods in parasitology and hydrobiology. The species affi  liation of trematodes was determined in laboratory conditions on mature cercariae that independently left the shells of the host mollusks Bithynia tentaculata and B. troscheli. It was noted that the trematodes of the Opisthorchiidae and Notocotylidae families at the cercaria stage have the following similar features: a simple tail, pigmented eyes, and one oral sucking cup. Diagnosis of trematode cercariae of Opisthorchiidae and Notocotylidae families is possible by the following signs: the tail of the opisthorchis cercaria has a swimming membrane and is 2 times longer than the body, the tail of the notocotylid has no swimming membrane and is approximately equal in length to the body. Opisthor-chis cercariae have two pigment eyes, notocotilids – three. In the life cycle of opisthorchis, there are two intermediate hosts (bitinia and fi  sh), in the notocotylid cycle, one (bitinia). Opisthorchis cercariae have penetration glands, but notocotylids do not; the maximum daily emission of opisthorchis cercariae is ten times higher than that of notocotylids (6672 and 422 cercariae, respectively). The ability to diagnose opisthorchis and notocotilid at the cercaria stage allows the identifi cation of local foci of epidemiologically and epizootically dangerous diseases.

2019 ◽  
pp. 371-378 ◽  
Author(s):  
Moskvin

The characteristics of ethnological characteristics of cercaria trematodes Schistosoma turkestanica Skrjabin, 1913 are detailed with emission from naturally invasive intermediate hosts, Lymnaea auricularia mollusks L., 1758.The modern correct species name of the dioecious trematodes of the Schistosomatidae family, the parasitic circulatory system of cattle in the Central Asian region, should be considered Schistosoma turkestanica Skrjabin, 1913.Spontaneous emission of furcocercarium Sch. turkestanica from invasive L. auricularia, can occur in various parts of the mollusk's body surface. The process of the release of the larva into the environment proceeds according to the original algorithm, accompanied by its morpho- functional adaptations, taking 15–17 seconds. The active initial transient phase of piercing “from inside-out” in the first 2–3 seconds is ensured by the body of the larva, which is drawn in length, taking the shape of a needle. Then, the tail of the cercaria is released from the puncture site. Tissue damage in the area of release of the larvae was not visually marked.Fourcocarii Sch. turkestanica have positive photo– and negative geotaxis, which modulate continuous two-phase, mainly vertical mobility, ensuring their long-term stay in the plankton state in the surface layers of water. Features of cervary ethology increase the likelihood of targeted active contact and the effectiveness of the attack of definitive hosts of the trematodes.


2016 ◽  
Vol 3 (3) ◽  
pp. 421-429 ◽  
Author(s):  
Сербина ◽  
E. Serbina

Objective of research: to perform the analysis of long-term (15 annum) dynamics of Bithyniidae snails infected by trematode parthenites from the Chany Lake, the biggest lake in the south of Western Siberia. Materials and methods: The Bithyniidae snails examined in the lake-river systems Chany Lake in 1994-2013 (in the middle reaches and in the estuary of the Kargat River) and in the Zolotye Rossypi Bay and the Malye Chany Lake. The Bithyniidae snails were collected from May to September (twice in any ten days) by hand from 4–6 plots of 0.25 m2 at a depth of 0.1–0.7 m. In total, 8,316 Bithynia troscheli (Paasch, 1842) and 766 В. tentaculata (L., 1758) were examined. Identification of parthenitae trematode was based on observation when mature cercariae were capable of leaving the shell of the host snail on their own. Results and discussion: In Bithyniidae snails, we found parthenites from trematodes from 12 families Cyathocotylidae Mühling, 1898 Poche, 1925; Prosthоgonimidae Luhe, 1909; Pleurogenetidae Looss, 1898; Lecithodendriidae Odhner, 1911; Microphallidae (Ward, 1901) Travassos, 1920; Plagiorchiidae Lühe, 1901 Echinostomatidae (Looss 1899) Dietz, 1909 Odhner 1910); Psilostomidae (Looss 1900) Odhner 1913; Notocotylidae Luhe, 1909; Monorchiidae Odhner, 1911; Cyclocoelidae Kossack, 1911 и Opisthorchidae (Lass, 1899) Braun, 1901. The prevalence of bithyniid snails infected by trematode parthenites varied from 1,6% to 24,1% in different years The double infection by trematode parthenites was found in 0,96% bithyniid snails from estuary of the Kargat River; 4,45% in the Malye Chany Lake, and 26,6%, in the Zolotye Rossypi Bay. The cercariae of Opisthorchidae family in four annum of the fifteen detected. The prevalence of bithyniid snails infected by trematode parthenites from Opisthorchis felineus (Rivolta, 1884) and Metorchis bilis (Braun, 1890) was observed in Chany Lake systems for the first time. Both species (O. felineus and M. bilis) of trematodes have danger to human health and causes very dangerous disease, opisthorchiasis and metorchiasis.


1989 ◽  
Vol 67 (6) ◽  
pp. 1421-1424 ◽  
Author(s):  
Cheryl A. Macdonald ◽  
Daniel R. Brooks

Pseudotelorchis compactus from the oviducts of Emydoidea blandingi is redescribed and its phylogenetic affinities examined. The Ochetosomatidae is considered the sister group of the Telorchiidae based on the shared presence of a well-developed glandular and muscular metraterm, and on the use of tadpoles as second intermediate hosts in the life cycle. The monophyly of the Ochetosomatidae is supported by the presence of relatively short caeca and testes located near the posterior ends of the caeca. The monophyly of the Telorchiidae is supported by the presence of postuterine testes located near the posterior end of the body. Orchidasma is excluded from the Telorchiidae because it possesses a spinose cirrus, spinose metraterm and distal portion of the uterus, and testes separated widely in the hind body by the uterus. Pseudotelorchis is considered monophyletic by virtue of having ovaries with irregular rather than smooth margins, testes that vary from side by side to tandem rather than being consistently tandem, and by inhabiting the oviducts rather than the intestine of the definitive hosts. Pseudotelorchis is the sister group of Loefgrenia plus Telorchis, the latter group diagnosed by having ovaries that are at least half an ovarian diameter posterior to the posterior margin of the ventral sucker rather than proximal to it. Loefgrenia is diagnosed by the absence of an esophagus, while Telorchis is diagnosed by strictly tandem testes with smooth margins and well-ordered ascending and descending uterine loops.


2020 ◽  
Vol 108 (4) ◽  
pp. 79-87
Author(s):  
E. Karatieieva ◽  
◽  
I. Lesik

The paper highlights the results of an analysis of the assessment of the main measurements of the heifers physique depending on their origin. Productive and breeding qualities of animals are determined by their exterior-constitutional type. Only well-developed, healthy animals are capable of high productivity and long-term use. And also constitutionally strong animals most fully correspond to the desired economic and biological indicators. Therefore, studies of the exterior of heifers of different breed combinations confirm that an increase in conditional blood count for the Red Danish and Angler breeds contributes to an improvement in the indicators of the exterior of the heifers towards a greater expression of the milky type of body structure, an increase in individual altitude and latitude measurements, the overall size and proportionality of the physique of animals. And the obtained results give grounds to assert that local heifers with 1/4 blood level in red Danish cattle significantly differ in the degree of development of linear measurements of the body structure from peers of the purebred and local group 3 / 4ES × 1/4 Ang. Keywords: exterior, body measurements, productive longevity, Angler breed, Danish red breed, conditional blood.


2006 ◽  
Vol 80 (4) ◽  
pp. 327-332 ◽  
Author(s):  
K. Umadevi ◽  
R. Madhavi

AbstractThe life cycle of the heterophyid fluke, Haplorchis pumilio is elucidated for the first time from the Indian region. Various stages in the life cycle were established based on observations made on natural infections found in snails and fish in a freshwater stream at Visakhapatnam, India and experimental infections carried out in the laboratory. The thiarid snail, Thiara tuberculata served as the first intermediate host and a wide range of freshwater fish as second intermediate hosts. Natural infections with adult flukes were found in the piscivorous birds Ardeola grayii and Bubulcus ibis. Adults were raised experimentally in day-old chicks. Distinguishing features of the cercaria of H. pumilio are: a large body size (200–224×92–96 μm), body–tail ratio of 1:2.1 and densely distributed pigment granules in the parenchyma imparting a brownish tinge to the body. Natural infections with metacercariae were found in the freshwater fish Channa punctatus, C. orientalis, Puntius sophore, Gambusia affinis and fingerlings of Cyprinus carpio and Liza macrolepis. Additionally, experimental infections were established in Therapon jarbua, Esomus danricus and Oreochromis mossambica. Metacercariae were embedded in the caudal muscles of fish and heavy infections induced mortality. Metacercariae were infective at about 15 days of age.


2007 ◽  
Vol 44 (3) ◽  
pp. 95-102 ◽  
Author(s):  
J. Dziekońska-Rynko ◽  
J. Rokicki

AbstractThe study was aimed at following, under laboratory conditions, embryogenesis of the nematode Contracaecum rudolphii, and at identifying its intermediate hosts in northeastern Poland. Nematode eggs, isolated from the terminal part of the female uterus, were placed in 0.9 and 3% NaCl solutions, 1% formalin, and in tap water. Each solution batch was divided into 3 parts kept at 4, 15, and 23°C. Regardless of the temperature they were exposed to, the eggs placed in 1% formalin showed numerous deformations; as few as 5% of those eggs produced larvae. Embryogenesis was at its fastest in the eggs kept at 23°C. While still within the eggs, the larvae underwent two moults. The eggs hatched to produce the stage 3 larvae, which emerged surrounded by the cuticle of the preceding larval stage. Experimental infestations of zooplankton collected from Lake Kortowskie showed that only cyclopoid copepods could serve as the intermediate hosts. No differences in the infestation intensity were found between the guppies infested by the invasive larvae and those fed the infested cyclopoids.


1957 ◽  
Vol 31 (4) ◽  
pp. 203-224 ◽  
Author(s):  
Roy C. Anderson

The evolution of the life cycles of the members of the family Dipetalonematiidae Wehr, 1935 (Filarioidea) is considered in the light of existing knowledge of spirurid nematodes. The hypothesis that the life cycles of the dipetalonematids originated from life cycles similar to those of Draschia megastoma, Habronema muscae and H. microstoma is considered to be incorrect. Alternatively, it is pointed out that in the primitive subfamily Thelaziinae Baylis and Daubney, 1926 there are forms with typical spiruroid life cycles (Rhabdochona ovifilamenta), forms with life cycles approaching those of the dipetalonematids (Thelazia spp.), and forms with life cycles intermediate between these two (Oxyspirura spp.). It is suggested that intestinal species similar to Rhabdochona gave rise to the more specialized spiruroids and forms that left the gut (Oxyspirura, Thelazia) gave rise to the dipetalonematids.The dipetalonematids are believed to have originated from nematodes resembling the species of Thelazia and having life cycles like those of T. rhodesii, T. skrjabini and T. gulosa. Some of these worms established themselves in subcutaneous tissues. Like Parafilaria multipapillosa, they released their eggs through a break in the skin of the definitive host, thus causing a skin lesion that attracted various haematophagous arthropods which finally became involved as intermediate hosts in the life cycle. Certain species like the members of Parafilaria and Stephanofilaria (?) came to rely upon intermediate hosts that were unable to break the skin of the definitive host (Musca) and cutaneous lesions became permanent features of their life cycles. Other species became dependent upon intermediate hosts that could puncture the skin (mosquitoes, simuliids etc.) and skin lesions became unnecessary to the life cycle. The larvae of these worms then began to spread into the tissues of the skin, as found in Stephanofilaria, Onchocerca, and some species of Dipetalonema, and the infective larvae developed the ability to penetrate into the wound made by the intermediate host and perhaps, in some cases, the intact skin. Ultimately the larvae of some species habitually entered, or were deposited into, the blood stream and the adult worms were then free to colonize the vertebrate body as their larvae would then be available to the intermediate host no matter where the latter fed on the body of the definitive host; this group of worms gave rise to the many members of the family Dipetalonematidae.The family Filariidae Claus, 1883 is briefly reviewed in the light of the above hypothesis. It is pointed out that many species, e.g. Diplotriaeninae Skrjabin, 1916, live in the air sacs of reptiles and birds and probably have life cycles similar to that of Diplotriaenoides translucidus, i.e. the eggs pass through the lungs, up the trachea and out in the faeces. It is thought that these forms may represent a separate line of evolution from that which gave rise to the Dipetalonematidae. Certain genera (Lissonema, Aprocta), occurring in the orbits of birds, probably have life cycles like Thelazia or Oxyspirura. Many other genera occurring in superficial muscles and subcutaneous tissues (Squamofilaria, Ularofilaria, Tetracheilonema, Pelecitus, Monopetalonema) may release their eggs through some sort of skin lesion. Studies on these forms are urgently needed as the details of their life cycles may shed fresh light on the origins of the more specialized filarioids.


2020 ◽  
pp. 1520-1528
Author(s):  
Richard Knight

Adult tapeworms maintain anchorage to the host small-gut mucosa by means the scolex, a holdfast structure. The rest of the body forms the strobila and consists of a chain of flattened proglottids, which proliferate just behind the scolex. The life cycle then includes larval stages in one or more intermediate hosts. Many species of tapeworm, all zoonoses, infect humans as adult worms or larval stages. Serious disease can result when larval stages occur accidentally in humans, whereas infections by the adult stages often cause little harm. Two groups of cestode infect humans: the Cyclophyllidea and the Pseudophyllidea. The former have a terrestrial life cycle and cystic larvae; the latter have an aquatic cycle and worm-like larvae.


1997 ◽  
Vol 2 (4) ◽  
pp. 293-300 ◽  
Author(s):  
Ype H. Poortinga ◽  
Ingrid Lunt

In national codes of ethics the practice of psychology is presented as rooted in scientific knowledge, professional skills, and experience. However, it is not self-evident that the body of scientific knowledge in psychology provides an adequate basis for current professional practice. Professional training and experience are seen as necessary for the application of psychological knowledge, but they appear insufficient to defend the soundness of one's practices when challenged in judicial proceedings of a kind that may be faced by psychologists in the European Union in the not too distant future. In seeking to define the basis for the professional competence of psychologists, this article recommends taking a position of modesty concerning the scope and effectiveness of psychological interventions. In many circumstances, psychologists can only provide partial advice, narrowing down the range of possible courses of action more by eliminating unpromising ones than by pointing out the most correct or most favorable one. By emphasizing rigorous evaluation, the profession should gain in accountability and, in the long term, in respectability.


2017 ◽  
Vol 1 (1) ◽  
pp. 115
Author(s):  
Sudar Kajin

Growth and development of the child have the nature of a thorough and intertwined relationships between components (health, nutrition, and environment). In general, child development can be grouped into three areas, namely cognitive, affective, and psychomotor, whereas biological growth which includes a change in the body structure. Body structure regarding the changes in bone structure, especially the long bones that have an impact on changes in body size, whereas changes in bodily functions is a result of hormonal changes that affect the physiological function .. The purpose of this development are: 1) Describe the product feasibility study التربية الجسمية for grade XI IPA at MAN I Mojokerto 2) Describe the development of learning tools using process skills can improve learning outcomes subjects التربية الجسمية class XI IPA at MAN I Mojokerto From the results of this development can be concluded: 1) results of expert validation and testing, the model approach process skills is fit for use for subjects of Physical Education, Sport and Health, because the products developed are not revised by experts but from the results of questionnaire of students stated that require revision are: (a) Improve the look model or change the learning strategy, and (b) improve the use of resources in implementing the model. 2) Product development learning tools using process skills can improve learning outcomes subjects التربية الجسمية class XI IPA at MAN I Mojokerto. From the class of the test increased learning completeness of Pre and Post Tests Tests are respectively 77.78% increase to 91.67%.


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