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1

Impact of diet on the fatty acids profile of European catfish (Silurus glanis L.)

100%
Jankowska B., Zakes Z., Zmijewski T., Ulikowski D., Kowalska A.
Archives of Polish Fisheries
|
2004
|
tom 12
|
nr 2
The aim of this study was to determine the impact of diet on the fatty acids profile in European catfish meat. The study material was comprised of fish reared in earthen ponds and fed with natural food and fish fed intensively with artificial feed in a recirculating system. The quality of the fatty acids profile in the meat of the two groups differed. A total of twenty-eight acids were identified in the catfish reared on natural food. The fish fed artificial feed contained an additional two acids – 22:1n-9 and 16:4, which were also detected in the artificial feed. The combined total share of saturated acids, MUFA, and PUFA was similar. However, the share of most of the fatty acids from these groups, including total PUFA n-6 and n-3 and HUFA n-3 and n-6, differed significantly. The catfish fed on artificial feed contained more n-3 acids and fewer n-6 acids. Above all, this was caused by the greater share of 20:5n-3 (eicosapentaenoic, EPA), 22:6n-3 (docosahexaenoic, DHA), and 20:3n-3 and 20:4n-3 acids and the lesser share of 18:3n-3 (a-linolenic, ALA) acid. The meat of the fish from this group also contained fewer 20:4n-6 (arachidonic, AA), 20:3n-6, and 22:5n-6 acids. Additionally, the n-3/n-6 acid ratio was significantly different at 2.31 (pond culture) and 3.93 (intensive culture on artificial feed).
2

European catfish (Silurus glanis L.) reproduction outside of the spawning season

100%
Ulikowski D.
Archives of Polish Fisheries
|
2004
|
tom 12
|
nr 2
The aim of this work was to develop methods of artificial European catfish reproduction outside of its natural spawning season using thermal and hormonal stimulation. Ovulation was induced with combined hormonal stimulation using a priming dose of Ovopel (0.3 granules in one dose or 0.2 and 0.3 granules in two doses per kg of female body weight) and a resolving dose of carp pituitary extract (CPE) (3 mg per kg of female body weight). The latency period between the doses was 24 hours. The males were stimulated with one dose of Ovopel (1 granule per kg of body weight). The results obtained indicated that the application of the appropriate thermal and hormonal stimulation, without light stimulation, can induce artificial spawning in the European catfish between January and August. It was revealed that the time between the injection of the resolving dose and egg collection decreased over this period. Thus, ovulation could be stimulated faster than in winter and spring. The number of eggs obtained in pre-season spawning was greater when the thermal treatment was longer. The results obtained indicate that the application of Ovopel in two stimulation doses instead of one was advantageous for the effectiveness of European catfish pre-season spawning, the number of eggs obtained as well as its survival. The results obtained during artificial European catfish reproduction conducted before, during, and after its natural spawning period were comparable.
3

Fatty acids profile in dorsal and ventral sections of fillets from European catfish (Silurus glanis L.) fed various feeds

84%
Jankowska B., Zakes Z., Zmijewski T., Ulikowski D., Kowalska A.
Archives of Polish Fisheries
|
2005
|
tom 13
|
nr 1
The aim of the research was to compare the basic composition and fatty acids profile from dorsal and ventral fillets of European catfish cultivated in earthen ponds on natural feed with those from fish fed artificial feed under intensive cultivation in recirculating systems. The lipid content in the dorsal and ventral fillets of catfish fed natural feed varied and were higher in the ventral fillets (P < 0.01). The lipid content of catfish fed artificial feed was equal (P > 0.01). The fatty acids profiles of dorsal and ventral fillets from catfish fed natural feed differed, while no such differences were noted in the fillets of fish fed artificial feed. It was revealed that the differences between the dorsal and ventral fillets of catfish cultivated on natural feed mainly regarded unsaturated; this led to different relationships between the amounts of MUFA and PUFA. This was due to the various amounts of oleic, palmitic, and mainly docosahexaenoic (DHA) acids. It was also determined that a 100 g ventral fillet from catfish cultivated on natural feed had an approximately two-fold higher content of various fatty acids, especially those from the valuable n-3 group, than did dorsal fillets. No such difference was noted in catfish cultivated with artificial feed in recirculating systems.
4

Impact of metabolic food rations on results of rearing of 2-year-old European catfish [Silurus glanis L.] in cooling water

84%
Filipiak J., Sadowski J., Trzebiatowski R.
Zeszyty Naukowe. Akademia Rolnicza w Szczecinie. Rybactwo Morskie i Technologia Żywności
|
1997
|
tom 23
5

Motility of European catfish Silurus glanis spermatozoa in testes and in milt

84%
Billard R., Linhart O., Fierville F., Cosson J.
Polskie Archiwum Hydrobiologii
|
1997
|
tom 44
|
nr 1-2
6

Sanitary and bacteriological studies of water and European catfish [Silurus glanis L.] during wintering

84%
Golas I., Lewandowska D., Zmyslowska I., Teodorowicz M.
Archives of Polish Fisheries
|
2002
|
tom 10
|
nr 2
Sanitary and bacteriological studies were conducted during European catfish (Silurus glanis L.) wintering from January 3, 2001 to March 7, 2001. Samples of water, skin and digestive tract contents were collected every two weeks. Qualitative analyses included culturing heterotrophic bacteria on a broth-agar medium at temperatures of 4ºC for 7 days of incubation (TVC 4ºC), 22°C for 72 hours of incubation (TVC 22°C) and 37°C for 24 hours of incubation (TVC 37° C). The total number of coliforms (TC), the total number of fecal coliforms (FC) and the total number of fecal streptococci (FS) were determined. The results obtained confirmed that the sanitary and bacteriological state of the water in the wintering pond was good. The number of microbes per cm² of skin varied from 10³ to 10⁴ , and in 1 g of digestive tract contents from 10³ to 10⁵ .
7

Evaluation of selected feeds differing in dietary lipids levels in feeding juveniles of wels catfish, Silurus glanis L.

67%
Mazurkiewicz J., Przybyl A., Golski J.
Acta Ichthyologica et Piscatoria
|
2008
|
tom 38
|
nr 2
91-96
Background. Development of modern aquaculture and the increasing consumer demand provoke improvements in the complex breeding technologies of economically valuable fish species. Wels catfish, Silurus glanis L. (known also as the European catfish), because of its breeding and consumption values, becomes an increasingly common object of breeding. The objective of the presented work was the evaluation of selected feeds differing in dietary lipids levels applied in rearing the wels catfish fry under controlled conditions. Materials and Methods. The feeding trial (60 days) was carried out with the wels catfish fry, weighing on average 55 g. The experiment was conducted under controlled conditions in an aquarium hall in 60-L flow-through tanks. During the growth test, the fish were given four commercial feeds of the same protein amount (45%) and graded fat levels (15%, 20%, 25%, and 30%). In the final evaluation of the feeding tests, the following rearing effectiveness indices were used: food conversion ratio (FCR), specific growth rate (SGR), protein efficiency ratio (PER), protein retention (PR), lipid retention (LR), and survival rate (SR). Conclusions were drawn on the basis of statistical analysis using Statistica computer software. Results. The wels catfish fed 20%-fat-content feed attained the highest individual weights. The other treatments yielded statistically significantly lower (P < 0.05) body weights. No statistically significant differences were found between the mean values of the specific growth rate (SGR). The values of feed conversion ratio (FCR) and protein efficiency ratio (PER) were approximately equal in the individual groups. The protein retention attained values from 28.2% to 33.0%, while fat retention ranged from 11.8% to 24.2%. No mortalities were recorded. The amount of fat in all groups increased significantly after the termination of the growth. The increase of fat amount in the feed was not correlated with the growth of fat amount in the fish body. The levels of the other body components increased, but no differences between the groups were found. Conclusion. Differentiated amounts of dietary lipids in the diet did not exert any effect on the rate of fish growth or on the proper utilization of the nutritive components in feeds.
8

Freshwater fish - an important source of n-3 polyunsaturated fatty acids: a review

67%
Steffens W., Wirth M.
Archives of Polish Fisheries
|
2005
|
tom 13
|
nr 1
In addition to n-6 fatty acids, n-3 polyunsaturated fatty acids are essential ingredients of the human diet. Many marine fish contain high levels of these fatty acids; however, freshwater fish are also an important source of n-3 fatty acids, especially eicosapentaenoic and docosahexaenoic acids. Generally, there is a balanced relation between n-3 and n-6 fatty acids in freshwater fish. Just as other animals and humans, fish cannot synthesize the essential fatty acids of the n-6 and n-3 series. Thus, these fatty acids must be supplied by the diet, and their original source is plants, particularly phytoplankton. The fatty acid composition of fish is strongly influenced by the lipid pattern of their food. Feeding high energy diets containing high amounts of fish oil in aquaculture results in marketable fish with substantial levels of n-3 polyunsaturated fatty acids. Several investigations have shown that the consumption of freshwater fish has beneficial effects on human health, especially for persons suffering from cardiovascular diseases. This is why freshwater fish is recommended as wholesome food for humans.
9

The microbiological state of fish feed, water, and Silurus glanis L. skin of fry during intensive rearing

67%
Golas I., Zmyslowska I., Harnisz M., Teodorowicz M., Lewandowska D., Szarek J.
Bulletin of the Sea Fisheries Institute
|
2004
|
nr 1
10

Artificial insemination and gamete management in European catfish, Silurus glanis L.

67%
Linhart O., Billard R., Kouril J., Hamackova J.
Polskie Archiwum Hydrobiologii
|
1997
|
tom 44
|
nr 1-2
11

Controlled reproduction of European catfish [Silurus glanis L.] in small ponds without artificial nests

67%
Stevic I., Opacak A., Bogut I.
Polskie Archiwum Hydrobiologii
|
1997
|
tom 44
|
nr 1-2
12

Changes in contents of zinc and copper in organs and blood of nickel-exposed European catfish, Silurus glanis L.

67%
Sobecka E., Protasowicki M.
Acta Ichthyologica et Piscatoria
|
2002
|
tom 32
|
nr 1
Effects of nickel, administered as aqueous solutions of nickel (II) nitrate (V), on European catfish, Silurus glanis L. were studied. The fish were at first exposed for 24 h (short-term exposure). The results obtained during the short-term exposure were used to determine the amount of nickel to be used during a 60-d (long-term) exposure. A significant effect of nickel on the distribution of zinc and copper in the fish blood and organs was found. The changes may have produced disturbed metabolism of the microelements under study during biochemical and energetic processes in the fish. Neither the short- nor the long-term exposure of the fish to nickel resulted in a significant accumulation of the metal in muscles; nor were changes in the microelement concentration in muscles observed.
13

Fatty acids and cholesterol in some freshwater fish species in Poland

67%
Bieniarz K., Koldras M., Kaminski J., Mejza T.
Folia Universitatis Agriculturae Stetinensis. Piscaria
|
2000
|
tom 27
14

Active bacteria in transitions of nitrogen compounds in pond water during the wintering of European catfish [Silurus glanis L.] fry

67%
Lewandowska D., Golas I., Zmyslowska I., Teodorowicz M.
Polish Journal of Natural Sciences
|
2003
|
tom 14
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