scholarly journals Histopathological changes in the stomach wall of the European grayling Thymallus thymallus associated with severe infection by the nematode Cystidicoloides ephemeridarum

2017 ◽  
Vol 73 (11) ◽  
pp. 687-689
Author(s):  
Marek Kulikowski ◽  
Zenon Sołtysiak ◽  
Jerzy Rokicki
Keyword(s):  
Histological Examination ◽  
Developmental Stages ◽  
Severe Infection ◽  
Stomach Wall ◽  
Histopathological Changes ◽  
Thymallus Thymallus ◽  
Stomach Mucosa ◽  
European Grayling ◽  
Common Parasite

This study is a report of lesions associated with the nematode Cystidicoloides ephemeridarum (Linstow, 1972). It is a common parasite of the stomach mucosa of fish, mainly salmonids. In stomachs of 30 graylings were observed strong infection with C. ephemeridarum caught in July 2013 and February 2014 in the Dobrzyca River were examined. Adult nematodes, including females with mature eggs, and L3 and L4 larvae were recorded. Stomachs of graylings with intensive infection (146–261examples) were examined. The histological examination of a sample taken from the tissue surrounding nematodes revealed the presence of more or less confluent focal areas of destruction of gastric laminae. The numerous invasions of C. ephemeridarum are associated with intensive feeding of fish, but the different developmental stages of the parasite do not induce sufficiently strong histopathological changes in the stomach of graylings to be a cause of their death.

scholarly journals Genetic population structure of the monogenean parasite Gyrodactylus thymalli and its host European grayling (Thymallus thymallus) in a large Norwegian lake

Hydrobiologia ◽  
2020 ◽  
Author(s):  
Ruben Alexander Pettersen ◽  
Claudia Junge ◽  
Kjartan Østbye ◽  
Tor Atle Mo ◽  
Leif Asbjørn Vøllestad
Keyword(s):  
Genetic Structure ◽  
Evolutionary Biology ◽  
Isolation By Distance ◽  
Genetic Structuring ◽  
Thymallus Thymallus ◽  
Homing Behavior ◽  
Genetic Population ◽  
Monogenean Parasite ◽  
European Grayling ◽  
Genetic Clusters

Abstract Understanding how populations are structured in space and time is a central question in evolutionary biology. Parasites and their hosts are assumed to evolve together, however, detailed understanding of mechanisms leading to genetic structuring of parasites and their hosts are lacking. As a parasite depends on its host, studying the genetic structure of both parasite and host can reveal important insights into these mechanisms. Here, genetic structure of the monogenean parasite Gyrodactylus thymalli and its host the European grayling (Thymallus thymallus) was investigated in 10 tributaries draining into the large Lake Mjøsa in Norway. The population genetic structure of spawning grayling was studied using microsatellite genotyping, while G. thymalli was studied by sequencing a mitochondrial DNA gene (dehydrogenase subunit 5). Two main genetic clusters were revealed in grayling, one cluster comprising grayling from the largest spawning population, while the remaining tributaries formed the second cluster. For both taxa, some genetic differentiation was observed among tributaries, but there was no clear isolation-by-distance signature. The structuring was stronger for the host than for the parasite. These results imply that moderate to high levels of gene flow occur among the sub-populations of both taxa. The high parasite exchange among tributaries could result from a lack of strong homing behavior in grayling as well as interactions among individual fish outside of the spawning season, leading to frequent mixing of both host and parasite.

Heterochromatin Studies and Localization of NORs in European Grayling (Thymallus Thymallus, Pisces, Thymallidae)

Caryologia ◽  
1988 ◽  
Vol 41 (3-4) ◽  
pp. 245-249 ◽  
Author(s):  
M. Kalat ◽  
B. Mayr ◽  
P. Rab ◽  
W. Schleger
Keyword(s):  
Thymallus Thymallus ◽  
European Grayling

scholarly journals DIET OF EUROPEAN GRAYLING (THYMALLUS THYMALLUS L.) FROM RIVERS OF THE ZAKARPATTYA IN CURRENT CONDITIONS

2014 ◽  
pp. 22-30
Author(s):  
A. Khandozhivska ◽  
◽  
S. Krazhan ◽  
A. Mruk ◽  
S. Koba ◽  
...  
Keyword(s):  
Thymallus Thymallus ◽  
European Grayling

scholarly journals Histopathological changes in pigs infected with ileitis

2020 ◽  
Vol 10 (4) ◽  
pp. 72-77
Author(s):  
O.M. Yermolenko ◽  
O.Y. Ayshpur ◽  
I.Yu. Mushtuk
Keyword(s):  
Histological Examination ◽  
Severe Disease ◽  
Gastrointestinal Diseases ◽  
Pathological Changes ◽  
Histopathological Changes ◽  
Lawsonia Intracellularis ◽  
Early Diagnostics ◽  
Chronic Effect ◽  
Anatomical Changes ◽  
Proliferative Enteropathy

Nowadays, the ileitis (proliferative enteropathy of pigs) is one of the most common gastrointestinal diseases. The intracellular bacterium Lawsonia intracelluaris causes several forms of the disease. Histological examinations are the important stages in diagnosing and detecting profound pathological changes in sick pig organs, decreasing their productivity and causing the deaths. Swine proliferative enteropathy (SPE) has reported for the Ukraine since 2008. For SPE the early diagnostics with different test systems is relevant. We evaluated the sick, forcibly killed and dead piglets of different ages in Ukrainian pig farms during 2018-2019 in animal fattening groups. Materials were taken from piglets aged 120-150 days in farms where the ileitis was diagnosed. To assess the complex of pathological and anatomical changes detected during autopsies of piglets, V.P. Shishkov’s methods were used. Thus, we revealed a characteristic morphology of proliferative lesions. We believed that the histological examination can serve as an important diagnostic method and an alternative to direct isolation of Lawsonia intracellularis, which is very difficult to cultivate. We determined that the histopathological changes in pig organs indicated a chronic effect caused by animal pathogen. We revealed that Lawsonia intracellularis caused the profound pathological changes in pig digestive tracts, which affected the functioning of all organs and tissues of animals and lead to severe disease and possible animal death. We suggested that the histological examination is an important step in diagnosing and detecting profound pathological changes in the organs of sick pigs, which caused the decrease in their productivity and deaths.

Amyloodinium sp. (Brown, 1931) (Dinoflagellida) infestation in captive stock of silver moony, Monodactylus argenteus (Linnaeus, 1758)

2020 ◽  
Vol 67 (4) ◽  
Author(s):  
Dani Thomas ◽  
A. Navaneeth Krishnan ◽  
P. Ezhil Praveena ◽  
J. Raymond Jani Angel ◽  
M. Kailasam ◽  
...  
Keyword(s):  
Severe Infection ◽  
Source Water ◽  
Histopathological Changes ◽  
Cell Hyperplasia ◽  
Potential Sources ◽  
Triggering Factor ◽  
Gill Lamellae ◽  
Infectious Form ◽  
Scanning Electron ◽  
Water Borne

This study was undertaken to investigate the cause of mortality in the captive stock of silver moony Monodactylus argenteus. The fishes showed severe infection of dinoflagellate protozoan Amyloodinium sp. (Blastodinida, Oodiniaceae) on gills and skin with complete mortality of the stock within a week. Histopathological changes were evident in the gill tissues with severe lamellar epithelial cell hyperplasia and lamellar fusions with the presence of trophonts of Amyloodinium sp. Scanning electron microscopy (SEM) also revealed trophonts of Amyloodinium sp. of varying sizes in groups consisting of 3 to 5 trophonts tightly attached to gill lamellae. Source water contaminated with the tiny infectious form of the parasite (dinospores) favoured by higher salinity and low water temperature in the rearing tank could be the triggering factor for the spurt of infections. Proper quarantine and biosecurity protocols to prevent the potential sources of water-borne infection sources are likely to be far more effective than treatment.

Ontogeny of the Electroreceptive System of The Platypus.

1998 ◽  
Vol 20 (2) ◽  
pp. 309
Author(s):  
P.R. Manger ◽  
R. Collins ◽  
J.D. Pettigrew
Keyword(s):  
Histological Examination ◽  
Developmental Stages ◽  
Developmental Profile ◽  
Adult Pattern ◽  
Poorly Differentiated ◽  
Sensory Structures

A series of developmental stages of the platypus were examined in order to obtain an anatomical description of the development of the periphery of the electroreceptive system. Putative electroreceptors, composed of modified mucous glands, were observed to appear at I0 days post hatching (p.h.). The typical striped arrangement of peripheral electroreceptors in the platypus was seen at 12 days p.h. The arrangement of the stripes was modified during development with a range of additions and divisions of stripes occurring until the adult pattern is obtained, approximately 6 months p.h. After appearing at 10 days p.h. the number of electroreceptors increases rapidly until sometime between 24 and 28 days p.h. when there is massive death of electroreceptors, the number present at 28 days p.h. being 60% of the number present at 24 days p.h. This massive death of receptors is coincident with the appearance of other sensory structures in the epidermis of the bill skin, the push-rod mechanoreceptors and the sensory serous glands. Histological examination of a range of developmental stages demonstrated poorly differentiated innervation at 28 days p.h. which became differentiated and reached the adult configuration between 11 weeks p.h. and 6 months p.h. Lamination of the cells lining the duct of the electroreceptors showed a similar developmental profile. This study indicates that the electroreceptive system of the developing platypus is not functional, in a similar manner to the adult, until around the time the platypus leaves the nesting burrow. However, the system may be functional in the developing platypus, and speculatively may be used in the location o f the mammary region for suckling.

Optimisation of a fuzzy physical habitat model for spawning European grayling (Thymallus thymallus L.) in the Aare river (Thun, Switzerland)

2008 ◽  
Vol 215 (1-3) ◽  
pp. 122-132 ◽  
Author(s):  
Ans M. Mouton ◽  
Matthias Schneider ◽  
Armin Peter ◽  
Georg Holzer ◽  
Rudolf Müller ◽  
...  
Keyword(s):  
Habitat Model ◽  
Physical Habitat ◽  
Thymallus Thymallus ◽  
European Grayling
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