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1

Wzrost płoci (Rutilus rutilus L.) z rzeki Brdy

Dąbrowski J., Gackowski G.

Ekologia i Technika

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2016

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R. 24, nr 1

38--40

PL

Materiał do badań w liczbie 200 osobników płoci, w tym 112 samic i 88 samców pozyskano z dolnego biegu rzeki Brdy na terenie miasta Bydgoszcz. Płoć poławiano na wędkę na początku kwietnia 2014 r. Na każdym osobniku przeprowadzano pomiary długości ciała z dokładnością do l mm. Masę ciała określano z dokładnością do l g. Wiek oznaczano na podstawie łusek. Współczynnik kondycji obliczano za pomocą wzoru podanego przez Fultona, biorąc pod uwagę długość ciała w cm i masę całkowitą ciała w g. Samice płoci w porównaniu z samcami w poszczególnych grupach wieku osiągały podobne rozmiary długości ciała. Osobniki obu badanych płci w analizowanych grupach wieku charakteryzowały się zbliżoną masą ciała i kondycją. Płocie z rzeki Brdy na tle płoci pochodzących z innych środowisk słodkowodnych charakteryzowały się przeciętnym wzrostem długości i masy ciała.

EN

The research material of 200 specimens of roach (Rutilus rutilus L.), including 112 female and 88 male specimens, was caught in the lower Brda River at the April 2014. Length of body of each specimen was measured with accuracy of l mm directly after the catch. Mass of body was measured with accuracy of 1 g. Age was established on the basis of scales. The condition of roach was calculated using the Fulton formula. Female specimens in comparison to males were similar body size of the age groups. Male and female specimens were achieved similar body mass and condition of the age groups. Roach from lower Brda River were of average growth in comparison to roach inhabiting other sweet water environments.

2

Towards the optimal foraging strategy : is seasonal shift in the diet of Cormorants Phalacrocorax carbo (L.) in a dam reservoir the effect of water temperature or size pattern in fish assemblages?

Gwiazda R., Amirowicz A.

Polish Journal of Ecology

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2010

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Vol. 58, nr 4

783-792

EN

According to optimal foraging theory the prey choice strongly affects the benefitcost ratios. Predators search prey giving the highest benefit and costs of all components of predation (i.e. prey search, encounter, pursuit, capture, and handling) may be considerably reduced if the prey is more available. The study on Cormorant diet and the species composition of prey fish assemblages in the Dobczyce Reservoir (area 985 ha, submontane, eutrophic reservoir in Southern Poland) in spring (May-June) and in autumn (Oct-Nov) showed differences in the food composition and the prey size affected by seasonal changes in fish availability. The diet of Cormorant included eleven fish species and the dominant species in the food was roach in spring (72%) and roach and perch in autumn (49% in total). Roach and perch had the highest share in prey assemblages too (56% in spring, and 53% in autumn). Significant preference toward roach in spring was found. The share of roach and perch did not changed seas seasonally and could not explain the change in the composition of Cormorant diet. The range of the total length (LT) of fish in Cormorant diet was 3.5-35.2 cm. Diet consisted of distinctly smaller fish in autumn. Relative number of small fish was ca 3 times greater in this period compared to spring. Weighted mean of fish TL in prey assemblage was 20.0 cm for roach and 12.5 cm for perch in spring, and 11.8 and 8.1 in autumn, respectively. The proportion of average weight of roach (W = 0.004074 LT[^3.334]) to that of perch (W = 0.005779 LT[^3.260]) was greater in spring (4.1:1) than in autumn (2.9:1). Probably it can explain the diet shift in autumn. The switch to smaller but more abundant fish in autumn was not related to temperature but to fish availability which reduced the cost of searching and the prey may be easily found.

3

Płodność płoci (Rutilus rutilus L.) z dolnego biegu rzeki Brdy

Dąbrowski J., Gackowski G., Hoffa D.

Ekologia i Technika

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2009

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R. 17, nr 5

240-242

PL

Płocie do badań poławiano za pomocą wędki z rzeki Brdy w czwartej dekadzie kwietnia 2008 r. Połowów dokonywano na terenie miasta Bydgoszczy (w pobliżu ulicy Iławskiej). Łącznie do badań pozyskano 130 samic. Płodność absolutną obliczano metodą wagową, a płodność względną wyrażano na l g masy ciała samicy. Płodność absolutna badanych płoci w przedziale długości ciała od 12,7 do 20,7 cm wahała się od 7,3 do 37,7 tyś. jaj. Stwierdzono wyraźne zwiększanie się płodności absolutnej wraz ze wzrostem długości i masy ciała oraz wiekiem. Płodność względna badanych płoci wahała się w granicach od 126 do 265 jaj. Płocie z rzeki Brdy w porównaniu z płociami zasiedlającymi inne rzeki i zbiorniki charakteryzowały się znaczną płodnością.

EN

Roaches to investigation were carried out from Brda river in Bydgoszcz near Iławska street fourth decade of April in 2008, used fishing rod. Total 130 females were investigated. Absolute fecundity was determined with the gravimetric method and relative fecundity was calculated to l g of female's body weight. Absolute fecundity of investigated roaches for the body length from 12,7 to 20,7 cm ranged from 7300 to 37700 eggs. A clear increase of absolute fecundity was observed which were accompanied with increase of body length, weight and age. The relative fecundity of investigated roach ranged from 126 to 265 eggs. Roaches from Brda river had relatively higher fecundity than roaches from other rivers and lakes.

4

Lead and cadmium content in the meat tissues of fish from water ecosystems in the vicinity of a pesticide tomb

Skibniewska K.A., Guziur J., Marzec Z., Zaręba S., Grzybowski M., Szarek J.

Oceanological and Hydrobiological Studies

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2008

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Vol. 37, No.3

79-86

EN

Lead and cadmium levels were determined in the meat tissues of roach, bream, and carp netted in a lake and in fish ponds threatened by a pesticide tomb and in control basins in northeastern Poland. Concentrations in roach ranged from 20 to 124 ěg kg-1 of Pb and from 1 to 19 ěg kg-1 of Cd. In bream they were from 4 to 280 ěg kg-1of Pb and 2 to 28 ěg kg-1 of Cd, while in carp they were from 9 to 82 ěg kg-1 of Pb and 2 to 260 ěg kg-1 of Cd. The metal concentrations were low; no result exceeded admissible residue levels set forth by Polish law, and no evident contamination of fish by leakage from the pesticide tomb was detected.

5

Accumulation of selected metals in roach (Rutilus rutilus L.) from West Pomeranian lakes

Rajkowska M., Wechterowicz Z., Lidwin-Kaźmierkiewicz Pokorska K., Protasowicki M.

Ecological Chemistry and Engineering. A

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2008

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Vol. 15, nr 1-2

119-123

EN

The aim of this study was to determine concentrations of Fe, Mn, Zn, Cu, Pb and Cd in the kidney, liver, gill and muscle of roach (Rutilus rutilus L.) from tour lakes of West Pomerania in Poland. Serious individual variability of metal accumulation in roach organs was observed within groups collected from each lake. For that reason, metal concentrations in organs of roach from different lakes in most cases did not differ considerably. Metal concentrations in roach tissues [{mu}g/g wet weight] were within the range of: 1.5-120 (Fe), 6-195 (Zn), 0.1-10.7 (Mn), 0.2-10.2 (Cu), 0.01-0.23 (Pb) and 0.002-0.085 (Cd). Metal concentrations in the muscle tissue were on a low level - similar or lower than reported for roach by other authors. In all the organs, the two most toxic metals (Cd and Pb) were found in the smallest concentrations. We assume, that no significant metal pollution impacted on the roach habitats.

PL

Celem badań było oznaczenie zawartości Fe, Mn, Zn, Cu, Pb i Cd w nerkach, wątrobach, skrzelach oraz mięśniach płoci (Rutilus rutilus L.) z czterech jezior zachodniopomorskich. Zaobserwowano dużą zmienność osobniczą w kumulowaniu metali w narządach wśród ryb pobranych z tego samego jeziora. Stąd zawartości metali w narządach płoci z różnych jezior zwykle nie różniły się istotnie. Stężenia metali w narządach płoci [{mu}g/g mokrej masy] mieściły się w zakresie: 1,5-120 (Fe), 6-195 (Zn), 0,1-10.7 (Mo), 0,2-10,2 (Cu), 0,01-0,23 (Pb ) i 0,002--0,085 (Cd). Mięśnie kumulowały niewiele metali - na poziomie podobnym lub niższym, niż podawany przez innych autorów u płoci. We wszystkich narządach najmniej było dwóch najbardziej toksycznych metali (Cd i Pb), co potwierdza, że na środowisko życia tych ryb nie oddziałują żadne znaczące zanieczyszczenia metalami.

6

Correlation between the occurrence of parasites and body length of roach, carp bream, European perch, zander, and ruffe in the Vistula Lagoon estuary

Rolbiecki L.

Oceanological and Hydrobiological Studies

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2006

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Vol. 35, No.3

257-267

EN

The abundance and composition of parasitic faunas change with fish size (age). The correlation between the occurrence of parasites and body length of cyprinids (carp bream and roach) and percids (European perch, zander, and ruffe) in the Vistula Lagoon was analysed, based on 1856 fish specimens caught between 1994-1997. Of the 63 parasitic taxa identified, the presence of 17 was found to correlate with fish size. Differences in parasitic infection between fish length classes could be caused by body size (fish body surface), volume of water swallowed during active breathing of the fish, type of food ingested, life history (migrations, aggregation of fish fry and spawning adults), and the degree of resistance as well as accumulation of parasites (particularly larvae), predation (elimination of infected fish), and commercial fisheries.

7

An attempt to determine the share of zooplankton in food consumed by fish in the limnetic zone of a eutrophic dam reservoir

Pociecha A., Amirowicz A.

Oceanological and Hydrobiological Studies

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2003

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Vol. 32, No. 2

15-31

EN

Zooplankton was the only food component of common bream and silver bream, and the main food component of roach and bleak in the pelagic zone of the Dobczyce Reservoir (southern Poland) from April to October 1994. Cladocera and Copepoda constituted 67.9% of the food consumed by the whole fish community. The average size of eaten individuals ranged from 0.62 to 1.43 mm. Planktivorous fishes selected phytoplankton-controlling filtrators, mainly large Daphnia species, which were eliminated most effectively in the summer.