The current state and specifics of taxonomic structure of trematodes of freshwater molluscs in the Ukrainian Polissia

Geo&Bio ◽  
2021 ◽  
Vol 2021 (20) ◽  
pp. 27-33
Author(s):  
Olena Zhytova ◽  
◽  
Eleonora Korol ◽  

The paper presents results on the analysis of the taxonomic structure of the trematode fauna of the Ukrainian Polissia. It was found that the trematode fauna of freshwater molluscs in the Ukrainian Polissia is represented by 62 species. We supplemented the species composition of larvae of trematodes in the region with 23 species, 13 of which were first recorded in Ukraine. The results showed that the number of trematode species the definitive hosts of which are fishes have decreased. According to the obtained data, the most abundant trematode species of freshwater molluscs in the Ukrainian Polissia are those of the families Echinostomatidae, Plagiorchiidae, Diplostomidae, and Notocotylidae. The combined analysis of literature and original data revealed that in the basis of the regional trematode fauna of molluscs are species of the families Echinostomatidae (13 species) and Plagiorchiidae (10 species), which make up almost one-third of the total number of trematode larvae detected. A quite large portion of larvae belong to species of the families Notocotylidae (8 species), Strigeidae (7 species), Diplostomidae (5 species), and Haematolechidae (5 species). Most families (Diplodiscidae, Opisthorchiidae, Leucochloridiomorphidae, Prostogonimidae, Cathaemasiidae, Cyclocoelidae, Prohemistomatidae, and others) are represented only by 1–2 species. In freshwater molluscs of the studied region, we have found only 38 % of trematode species recorded in definitive hosts. Species found in vertebrate animals of the region potentially can also occur in intermediate hosts, but most of these species parasitize in birds that could be infected in other areas. When comparing the taxonomic structure of the trematode fauna of the Polissia with other well-studied regions of Ukraine (Northern Pryazovia and Crimea), some specifics were noted between them. In particular, it was found that the most abundant trematode species in the region as well as in the whole of Ukraine are those of the families Echinostomatidae, Plagiorchiidae, Diplostomidae, Notocotylidae, and Strigeidae. The obtained data allow considering that the trematode fauna of freshwater gastropods of the Ukrainian Polissia is an integral part of the Central European fauna of trematodes.

2019 ◽  
Vol 16 ◽  
pp. 00002
Author(s):  
Ekaterina Antipova ◽  
Olga Enulenko

Sidinskiy and Pribaitakskiy steppes are the part of the Minusinsk province of the Altai-Sayan mountain country. On the territory of steppes 12 local floras (LF) were marked and examined using the same method. Studies were carried out according to the recommendations of A.I. Tolmachev (1931): identification of different types of ecotypes of LF, the full species composition of ecotypes (flora inventory), tracking the completeness of detection in LF. In the Sidinskiy steppe the number of families in the LF varies from 25 (Syida) to 43 (v. Alha), in the Pribaitakskiy steppe there is a big difference in the number of families in the LF from 31 (Krasnoyarsk reservoir, Tuba) to 65 (Mayak, Idra). The leading families in the local steppe flora are Asteraceae, Poaceae, Fabaceae. The Fabaceae family ranks third in the top of ten families in 50 % of LF, determining the type of flora as the Mediterranean-Central Asian (Fabaceae-type). Different types of LF allow to determine the type of all steppe flora as mixed, combining features of boreal (Asteraceae-Poaceae- type) and steppes flora (Fabaceae-type) with close ties with Central European floras (Rosaceae-type). 4 distinct levels of species richness are determined: 1 − 496-544; 2 − 408-413; 3 − 319-374; 4 − 279-298 species.


Author(s):  
Mériame Gam ◽  
Hocein Bazaïri ◽  
K. Thomas Jensen ◽  
Xavier de Montaudouin

The metazoan parasite community of Cerastoderma edule was studied in the southern geographical range of the host (the coastal lagoon Merja Zerga, Morocco). A total of 11 metazoan species was found in cockles. Nine of these were trematodes using cockles as either first intermediate host (three species) or second intermediate host (six species). In addition, two other endo-metazoan species (Pinnotheres pisum and Paravortex cardii) were recorded from cockles in the studied lagoon. All the observed metazoans in cockles from Merja Zerga have previously been recorded at sites north of Africa.Up to 10% of the cockles in the studied size-groups were first intermediate hosts to castrating parasites (Gymnophallus choledochus, Labratrema minimus and Monorchis parvus). Among trematodes having metacercariae in cockles (second intermediate host) Meiogymnophallus minutus was the most widespread as it was observed in all cockles from all the examined habitats in the lagoon and it occurred in record high intensities. Different sub-communities of the trematode fauna using cockles as second intermediate host could be identified (subtidal vs intertidal associations).The richness and species composition of the macroparasite community in cockles from Morocco are discussed in relation to patterns seen in cockles from other sites along their geographical range. Migratory fish and waterbirds (final hosts) are generally responsible for the large scale spread (latitudinal spread) of trematodes. However, the distributional patterns of involved intermediate hosts in the life-cycles of the different trematode species in cockles are determining the richness and species composition patterns seen in cockles at shallow water sites along the east Atlantic shoreline.


2019 ◽  
pp. 61-72
Author(s):  
T. V. Belich ◽  
S. Ye. Sadogurskiy ◽  
S. A. Sadogurskaya

The results of nomenclature-taxonomic revision of the flora marine macrophytes of the Kazantip Nature Reserve (KNR) are presented. Currently, with the new data the species composition includes 73 species and intraspecific taxon (IST) of macroalgae and sea grasses. Taxonomic structure of flora of the macrophytes of the KNR includes 4 phylums, 7 classes, 19 orders, 28 families, (F), 37 genera. Chlorophyta - 33 species, Ochrophyta - 11, Rhodophyta - 25, Tracheophyta - 4. In the flora prevail mesosaprobic (44%), annuae (58%), brackish-sea (51%), warm-water (40%) species. The category of rare fraction includes 14 species.


Koedoe ◽  
1998 ◽  
Vol 41 (1) ◽  
Author(s):  
K.N. De Kock ◽  
C.T. Wolmarans

Most of the previous records of the freshwater molluscs from the Kruger National Park date back prior to and up to 1966. On account of several droughts between 1966 and 1995 it was decided to do a survey of the freshwater mollusc population in 1995 to evaluate the effect of these droughts. The traditional mollusc intermediate hosts were also screened for trematode parasites to establish whether or not they were infected. No infected molluscs were found. Eight of the 19 species reported up to 1966 were not found during the 1995 survey. Three new mollusc species were collected in 1995. The consequences of the drought are clearly visible when the species diversity found in the dams in the 1995 survey, is compared to what was previously recorded.


Parasitology ◽  
2005 ◽  
Vol 132 (1) ◽  
pp. 143-151 ◽  
Author(s):  
R. POULIN

Global warming can affect the world's biota and the functioning of ecosystems in many indirect ways. Recent evidence indicates that climate change can alter the geographical distribution of parasitic diseases, with potentially drastic consequences for their hosts. It is also possible that warmer conditions could promote the transmission of parasites and raise their local abundance. Here I have compiled experimental data on the effect of temperature on the emergence of infective stages (cercariae) of trematode parasites from their snail intermediate hosts. Temperature-mediated changes in cercarial output varied widely among trematode species, from small reductions to 200-fold increases in response to a 10 °C rise in temperature, with a geometric mean suggesting an almost 8-fold increase. Overall, the observed temperature-mediated increases in cercarial output are much more substantial than those expected from basic physiological processes, for which 2- to 3-fold increases are normally seen. Some of the most extreme increases in cercarial output may be artefacts of the methods used in the original studies; however, exclusion of these extreme values has little impact on the preceding conclusion. Across both species values and phylogenetically independent contrasts, neither the magnitude of the initial cercarial output nor the shell size of the snail host correlated with the relative increase in cercarial production mediated by rising temperature. In contrast, the latitude from which the snail-trematode association originated correlated negatively with temperature-mediated increases in cercarial production: within the 20 ° to 55 ° latitude range, trematodes from lower latitudes showed more pronounced temperature-driven increases in cercarial output than those from higher latitudes. These results suggest that the small increases in air and water temperature forecast by many climate models will not only influence the geographical distribution of some diseases, but may also promote the proliferation of their infective stages in many ecosystems.


2008 ◽  
Vol 3 (3) ◽  
pp. 307-319 ◽  
Author(s):  
Rimantas Rakauskas

AbstractInformation on the Aphis species that feed on evening primroses (Oenothera spp.) has been summarized in the catalogue of the aphid species inhabiting herbaceous plants of the world (Blackman & Eastop, 2006). Recent descriptions of the European species, A. holoenotherae (Rakauskas, 2007), that appeared to be a sibling of the American A. oenotherae, demonstrated the need of reexamining the current state of knowledge of the Aphis species inhabiting evening primroses in Europe. The present study, based on published original data, revealed nine aphid species of the genus Aphis which are capable of living on Oenothera plants in Europe. Only two of them are really dependent on Oenothera species during their life cycle: A. oenotherae Oestlund and A. holoenotherae Rakauskas. They have different life cycles and host plant spectrum, although they are very close in their morphology. Processus terminalis length appeared to be the most reliable morphological character in distinguishing between apterous and alate viviparous females, and males of A. oenotherae and A. holoenotherae at the present time. A. grossulariae is not a typical Oenothera-feeder in Europe, occurring on evening primroses only by chance. Other Aphis species (epilobiaria, fabae, sambuci, praeterita, frangulae, nasturtii), are opportunistic inhabitants of Oenothera plants. Information about host specificity and morphology of the Oenothera-inhabiting European Aphis species is summarized, and a key for the entire range of species found living on European Oenothera is provided.


2017 ◽  
Vol 26 (11) ◽  
pp. 973 ◽  
Author(s):  
Miguel G. Cruz ◽  
Martin E. Alexander ◽  
Andrew L. Sullivan

Generalised statements about the state of fire science are often used to provide a simplified context for new work. This paper explores the validity of five frequently repeated statements regarding empirical and physical models for predicting wildland fire behaviour. For empirical models, these include statements that they: (1) work well over the range of their original data; and (2) are not appropriate for and should not be applied to conditions outside the range of the original data. For physical models, common statements include that they: (3) provide insight into the mechanisms that drive wildland fire spread and other aspects of fire behaviour; (4) give a better understanding of how fuel treatments modify fire behaviour; and (5) can be used to derive simplified models to predict fire behaviour operationally. The first statement was judged to be true only under certain conditions, whereas the second was shown not to be necessarily correct if valid data and appropriate modelling forms are used. Statements three through five, although theoretically valid, were considered not to be true given the current state of knowledge regarding fundamental wildland fire processes.


2017 ◽  
Vol 38 (s2) ◽  
pp. 7-23 ◽  
Author(s):  
Filip Láb ◽  
Sandra Štefaniková

Abstract The adoption of digital technologies, along with current economic realities, has affected the entire process of visual news production. It has also influenced the traditional concept of photojournalism. As a result, news photographers face multiple new challenges. Although visual news material is becoming ever more important, news organizations have cut back on employment, leaving those few who remain employed with additional workload and responsibilities. Based on interviews with photojournalists and photo editors, this article examines the current state of photojournalism and editorial processes in three Central European countries – the Czech Republic, Poland and Slovakia. Findings indicate that photojournalists and photo editors face ongoing developments in the photographic medium that significantly affect their working practices and routines. At the same time, they must deal with increasing workload, new responsibilities, competition and the challenges of maintaining quality in the digital age.


Parasitology ◽  
1929 ◽  
Vol 21 (1-2) ◽  
pp. 189-219 ◽  
Author(s):  
W. F. Harper

A large number of fresh-water Invertebrates has been examined and the parasites obtained from them include examples of the commoner groups to be met with in any area surveyed. Six larval Trematodes have been described in detail, and by means of direct animal experiment two of them have been definitely related to known adults. Of these two one is the larva of Notocotylus seineti Fuhr., and is doubtfully Cercaria monostomi v. Linst., while the other is the larva of Echinoparyphium recurvatum v. Linst., and is described here in detail for the first time. The four xiphidiocercariae described are new. Data relating to the activity, duration of free life, and process of encystment of cercariae within the bodies of secondary intermediate hosts is also given.Effect of the parasite on the host. The disruption of the tissues brought about by the presence of sporocysts or rediae in the liver of a mollusc injures the host, and in many cases brings about its death. The gonads also are often attacked and completely destroyed. This latter feature of parasitic castration has been observed by Giard (1888) among certain species of Limnaea, Planorbis and Paludina attacked by sporocysts. Brown (1926) states that the gonads are rarely infected. As regards the encysted stages of cercariae these appear to do very little harm to their hosts even when present in large numbers. These observations are in agreement with those of Lebour (1912) for the sporocyst, rediae, and encysted stages of marine Trematodes.Double infection. I have found no instance of a double infection among the species described. In the literature, several records show the parasitism of two or more species of cercariae, within one and the same host. The occurrence of two species is most commonly met with, and as a rule one is in predominance. Sewell (1922) states that double infection is not common in India. Faust (1917), on the other hand, has found as many as four trematode species within the same host individual (Planorbis trivolis). Hesse (1923) states that “every large Limnaea peregra examined was heavily infected with sporocysts of either of the two species, but it was rare to find both together.” Brown (1926) in the neighbourhood of Birmingham has found three examples of associated xiphidiocercariae and furcocercariae, one example of xiphidiocercariae and echinostome cercariae, and two examples of echinostome cercaria, all from Limnaea stagnalis L.


2019 ◽  
Vol 437 ◽  
pp. 49-58 ◽  
Author(s):  
Frank M. Thomas ◽  
Katharina Krug ◽  
Jörg Zoldan ◽  
Hans-Werner Schröck

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