16 research outputs found
Monitoring of the Topmouth Gudgeon, <I>Pseudorasbora Parva</I> (Actinopterygii: Cypriniformes: Cyprinidae) in a Small Upland Ciemięga River, Poland
No full textBackground. The topmouth gudgeon, Pseudorasbora parva (Temminck et Schlegel, 1846) (known also as stone moroko), is an alien species of the fish fauna of many European freshwater ecosystems. In large quantities, its may affect negatively the fish fauna and the functioning of ecosystems. It competes for food with native fish species and they occupy their habitat. The knowledge about the invasion dynamics may help to find suitable control measures. The aim of this study was to find and observe the population of P. parva in a small river. Materials and methods. Inventory fishing on three sampling sites at the CiemiÄ™ga River was carried out from 2003 to 2007. The abundance and density of P. parva in the river were calculated. The size distribution of P. parva and its length–weight relation were determined. Abundance, density, length, and mass of the fish from all study sites were analyzed statistically. Results. P. parva was first recorded in the CiemiÄ™ga River in the autumn of 2005. The abundance of P. parva in relation to the structure of the local ichthyofauna was the smallest in the spring and the highest in autumn. The total length of P. parva ranged from 15 to 104 mm, and the mass from 0.2 to 10.4 g. Taking into account the number of the specimens, P. parva constituted between 0.9% and 57.2% of the local ichthyofauna, while its mass ranged from 0.0% to 35.1% depending on the study site and the season. The density of P. parva ranged from 72.9 to 6.5 CPUEN, while the mean value for the river was 30.6 CPUEN. Conclusion. In Polish waters P. parva is an alien species and there is still little information about its occurrence in the flowing waters. Since 2005, this species was present almost in all inventory catches in the CiemiÄ™ga River. Its presence was dependent on the kind of the habitat and the presence of predatory fish species (eg brown trout). P. parva occurring numerous may be a lot of competition for native fish species, and therefore an important problem is to understand his habitat preferences and interactions with native fish species
Age and growth rate of perch (Perca fluviatilis L.) from a special angling lake Skomielno
No full textDuring control fishing surveys carried out in the 2005 and 2006 on the special angling lake Skomielno, 56 perches were captured and their scales examined for determination of this species age and growth rate. There were performed individual measurements of fish, while its growth rate and body weight were established by the length-based methods and back-reading procedure. Perch condition was determined by calculating the Fulton coefficient. The age of perch from Skomielno fishing site ranged within I+ up to VIII+ age classes, while IV+ age group was a clear dominant (contributing 30.5% of all fish examined) as well as VI+ (22.2% of fish). The highest average perch length increment was recorded for juvenile fish of VII+ age-group (172 g) and slightly lower for V+ and VI+ ones, i.e. 91 g, 80 g, respectively. A condition coefficient calcu-lated for perches from Skomielno Lake averaged 2.3
Prisustvo i populacione karakteristike invazivne vrste amurski spavač (perccottus glenii) u mrtvajama u jugoistočnom delu Poljske
No full textAmur sleeper (Perccottus glenii, Dybowski 1877) is fish which in recent years has been regarded as an alien fish species in natural water ecosystems of Central Europe. In Poland, it was first recorded in 1993 in the middle part of the Vistula River. Because of its morphological and biological predispositions it is a threat to natural water ecosystems. This fish is characterized by high voracity, resistance to adverse environmental factors and a number of features conducive to invasion. The aim of this study was to determine the presence, abundance and percentage contribution of Amur sleeper in the fish fauna of oxbow lakes located in south-eastern Poland.
The study was conducted on two different terms (June and August) in 2012 in six oxbow lakes (No 1-6) located in the Wieprz River basin. Control fishing was carried out using electric fishing gear (IUP-12, 220-250V, 7A). All caught fish were identified to species and their total length (Lt; ± 1 mm) and weight were measured (W; ± 0.1 g). The species composition of the fish fauna of the oxbow lakes and the abundance of Amur sleeper were determined, as well as the size structure and density (in CPUE, i.e. ind.*100m-2*h-1 of fishing) of Amur sleeper.
A total of 14 fish species were found in the oxbow lakes. Amur sleeper was reported in four of the six surveyed oxbows. The total length of Amur sleeper ranged from 34 mm to 128 mm (on average 55 ± 26 mm) and varied depending on the study site. The average biomass of Amur sleeper was 5.4 g (± 7.3 g), ranging from 1.3 g to 11.8 g. The proportional contribution of Amur sleeper in the abundance of fish ranged from 40% in the oxbow in the vicinity of Latyczów (No 2) to 67.3% in the oxbow lake near the town of Wał (No 6). The density of this alien species ranged from 4.0 to 35.6 CPUE and depended on the study site. The size structure of the Amur sleeper population was clearly dominated by individuals with a total length of less than 50 mm.
To identify and determine the routes of dispersion of Amur sleeper into new areas, continuous fish fauna monitoring should be conducted. Moreover, it would be useful to find biological features of this species that would enable its elimination from freshwater ecosystems.Amurski spavač (Perccottus glenii, Dybowski 1877) je vrsta ribe koja se u toku poslednjih godina smatra alohtonom vrstom za prirodne vodene ekosistemime Centralne Evrope. U Poljskoj je prvi put zabeležena 1993. godine u srednjem delu reke Vistula. Zbog njenih morfoloških i bioloških predispozicija ona predstavlja pretnju za prirodne vodene ekosisteme. Ova vrsta ribe se karakteriše velikom proždrljivošću, otpornošću na nepovoljne faktore sredine i brojnim drugim odlikama karakterističnim za invazione vrste. Cilj ove studije je bio da se odredi prisustvo, abundanca i procentualni udeo amurskog spavača u fauni riba u mrtvajama koje se nalaze u jugoistočnom delu Poljske.
Istraživanja su obavljena u toku dva dana 2012. godine i obuhvatila su šest mrtvaja (No 1-6) koje se nalaze u basenu reke Wieprz. Izlov ribe je izvršen korišćenjem aparata za elektroribolov (IUP-12, 220-250V, 7A). Svi izlovljeni primerci riba su određeni do nivoa vrste i izmerena je njihova totalna dužina (Lt; ± 1 mm) i totalna težina (W; ± 1 g). Određen je ihtiofaunistički sastav mrtvaja i abundanca amurskog spavača, kao i dužinska i težinska struktura i gustina (kao CPUE, tj. ind.*100m-2*h-1 izlovaljavanja) ove vrste.
Ukupno je nađeno 14 vrsta riba u istraživanim mrtvajama. Amurski spavač je nađen u 4 od 6 ispitivanih mrtvaja. Totalna dužina amurskog spavača je bila u rangu od 34 mm do 128 mm. (u proseku 55 ± 26 mm) i varirala je u zavisnosti od istraživanog lokaliteta. Prosečna biomasa amurskog spavača je bila 5.4 ± 7.3 g i varirala je od 1 g to 12 g. Proporcionalni udeo amurskog spavača u abundanci riba je varirao od 40% u mrtvaji u blizini lokacije Latyczów (No 2) do 67.3% u mrtvaji u blizini grada Wał (No 6). Gustina ove alohtone vrste je varirala od 4.0 do 35.6 CPUE i zavisila je od istraživanog lokaliteta. U dužinskoj strukturi populacije amurskog spavača dominirale su jedinke sa totalnom dužinom manjom od 50 mm.
U cilju identifikacije i određivanja puteva širenja amurskog spavača u nove oblasti, potrebno je vršiti kontinualni monitoring ihtiofaune. Štaviše, bilo bi korisno pronaći biološke karakteristike ove vrste koje bi omogućile njenu eliminaciju iz slatkovodnih ekosistema
Changes in a Fish Community in a Small River Related to the Appearance of the Invasive Topmouth Gudgeon Pseudorasbora parva (Temminck & Schlegel, 1846)
No full textIn recent years, the topmouth gudgeon (Pseudorasbora parva) has been one of the most invasive fishes in Europe. Pseudorasbora parva can potentially affect ecosystems, fish communities, and particular fish species. Electrofishing was carried out over a five-year period at three study sites in the Ciemięga River (eastern Poland) before and after P. parva had been found in the river. Changes in the occurrence, abundance, and density of native fish species after the appearance of the invader were determined. Changes in the species’ richness were calculated, and correlations were estimated between the occurrence and density of P. parva and particular fish species and richness indices. The presence of P. parva has not affected the density of native species but coincides with a significant increase in estimated species richness and the total density of fish. There was a significant relationship between the presence of this invasive species and the fish community’s composition, though the PERMANOVA result was unclear with regards to site-specific effects. Moreover, tench and bleak were associated positively, whereas Eurasian perch and sunbleak were associated negatively with the occurrence of P. parva. Pseudorasbora parva density was highly correlated with Cyprinidae density (excluding P. parva), species richness, and the Margalef diversity index. Thise study has shown that the presence of predatory fish in the river (Salmo trutta L.) may reduce the numbers of invasive P. parva
Preliminary study of ichthyofauna in extensively exploited Głębokie Uścimowskie Lake with abnormal fish structure
No full textThe aim of research was to define the structure of ichthyofauna in a shallow, eutrophic lake where stocking and commercial catches were no conducted for over a dozen of years. In years 2008–2011 control fish catches were made with the use of gill nets. Based on this catches, 10 species of fish were found (in total) in this lake. During entire period of research 3 species of fish: Prussian carp, roach and brown bullhead were dominated in biomass and quality. During four years of research an upward trend in quantity and total biomass in Prussian carp population was observed. Caught fishes were got rather small and because of that they did not show any economic value. The ichthyofauna of Głębokie Uścimowskie Lake had untypical structure, with total absence of predator fish species. This abnormal in trophic structure probably had a significant impact on fish growth parameters such as small size and mass below 0.2 kg
Effect of water temperature and time since of administration of ascorbic acid (AA) on its contents in selected tissues of the common carp Cyprinus carpio (L.)
No full textThe effect of water temperature and time after administration of ascorbic acid (AA) on its content in selected tissues of carp kept in different thermal conditions (15oC and 25oC) wasdetermined. The concentration of AA in the kidney, liver and muscle of common carp before the experiment (control) and on 1, 3, 7 and 14 days after per os its administration was determined. The greatest content of AA was found in the kidney, while being smaller in the liver and the smallest in muscles, the average being 14.1 µg kg-1, 12.2 µg kg-1
and 8.3 µg kg-1, respectively. On the first day after administration of AA its quantity in the kidney was 2.5 times higher and in the liver, twice as high as in the control sample. During the experiment, the AA content significantly decreased and after 14 days after dosing it fell to the value defined in the control sample. The water temperature did not significantly affect the decline of AA in all tissues, but a two-way analysis of variance revealed significant effects of temperature on the changes of AA content only in the liver
Morphological differences between lake and river populations of roach – Rutilus rutilus (L.)
No full textFour populations (two from rivers and two from lakes) of roach Rutilus rutilus (L.) were tested for a variation of morphological features depending on the given habitat. 23 biometricand 11 meristic variables were analysed. The compared fish populations showed little variability as regards the meristic features. Lake roaches were characterised by higher values of biometric characteristics than the river populations. The habitat affected the selected biometric variables. The following features: eye diameter, length of the caudal peduncle and head depth were the least changeable. The greatest differences between the fish populations were identified in the case of head and body width. River roaches had higher fins and a greater predorsal length. The lake roach populations were showed greater pectoral – pelvic fin distances. Moreover, the fish from lakes were characterized by lower variability of countable traits as compared with the river fish
Indirect effect of environmental factors on interactions between microbial and classical food webs in freshwater ecosystems
No full textThe role of environmental factors in aquatic ecosystems results from basic lake characteristics, human disturbances (‘cultural eutrophication’) and climate-related trends in the physical and chemical components of lakes. Although the influence of environmental factors on the abundance of aquatic animals is fairly well documented, less has been done to research their influence on food web interactions. The aim of the study was to evaluate microbial and classical food webs in lakes, with special emphasis placed on the role of environmental factors as influencing strengths. Variation partitioning, based on redundancy analysis, revealed that environmental factors played the most important role in structuring aquatic communities by accounting for 87.5% of their variation. Among all the factors measured, total solids (TS), transparency (Secchi disc) and temperature were most closely related to the variation in trophic communities. The analyses of food web interactions under low and high levels of those factors revealed that they differently influenced strengths among food web components. The strongest relations among distinct trophic levels were found under conditions of low TS, the lowest number of relations was found under conditions of low temperature. Only in low TS did bacteria correlate significantly with biogenes. Under high TS, bacteria positively influenced plenty of higher trophic levels. Top-down control was observed under conditions of high temperature. Conditions of low and high transparency did not diversify food web interactions. The obtained results can broaden our knowledge of the response of food webs to environmental factors in advanced stages of global eutrophication of water bodies and in the early stage of projected trends of global climate change.While the influence of environmental factors on the abundance of aquatic animals is fairly well documented, less has been done to research their influence on food web interactions. Among a plenty of environmental factors measured, total solids, transparency and temperature were most closely related to the variation in trophic communities. The analyses of food web interactions under low and high levels of those factors revealed that they differently influenced strengths among food web components
