Wyniki wyszukiwania - BazTech

1

The Signal Crayfish Pacifastacus leniusculus : Distribution and Invasion in the Southern Baltic Coastal River

Dobrzycka-Krahel A., Skóra M. E., Raczyński M., Szaniawska A.

Polish Journal of Ecology

|

2017

|

Vol. 65, nr 3

445--452

EN

The signal crayfish Pacifastacus leniusculus (Dana, 1852) of North American origin was introduced to Europe (to Scandinavia) in the 1960s. Since that time due to translocation to many countries, biological features and ecological plasticity, it became widespread, invasive and displaced native species. The paper reports first multi- point colonization of P. leniusculus in the Polish rivers. The aim of the study was to determine the current distribution of the signal crayfish in the coastal Baltic tributary (the River Wieprza) after 20 years of deliberate releases in its drainage area. During sampling at 28 sites with use of the “Pirate” crayfish traps and hand collection methods in spring and summer 2014, 127 P. leniusculus individuals were found at 8 sites in the Wieprza and its two tributaries, both away from and close to known sites of their introduction in 1995 and 1996 in the Wieprza River drainage area. The species spreads via the Wieprza River towards the Baltic brackish waters. With such expansion of this species, it is expected to be found in Polish coastal waters of the Baltic Sea and in other coastal rivers in the near future. The conflict between legal aspects of the signal crayfish farming, colonization by the species of the natural aquatic ecosystems and the expectations of consumers is discussed.

2

Is the body condition of the three-spined stickleback (Gasterosteus aculeatus) determined by the type of food consumed?

Pawelec A. J., Sapota M. R., Skóra M. E.

Oceanological and Hydrobiological Studies

|

2016

|

Vol. 45, No. 4

588--599

EN

The three spine stickleback Gasterosteus aculeatus is a small omnivorous, wildly distributed fish. In this study, food uptake and body condition of three spine stickleback, from the Gulf of Gdansk eulitoral was investigated. Samples were taken from three locations of the Gulf of Gdańsk: in vicinities of Sopot, Chałupy and Hel. Copepods were the most quantitive food components in the three spine stickleback stomachs. In spring, at Hel station -Harpacticoida and in Sopot, crustacean and fish eggs, were dominating as a fish prey. During summer, Calanoida were most abundant in stomachs collected from fish caught in Chałupy, fish eggs and Calanoida in those from Hel station. In stomachs of fish from Sopot location most common prey were Cladocera. Comparison of stomach content to food base and Fulton’s body condition index revealed that the three spine stickleback uses available food base in efficient way.

3

Diet of the twaite shad Alosa fallax (Lacépčde, 1803) (Clupeidae) in the Gulf of Gdansk, the Baltic Sea

Skóra M. E., Sapota M.R., Skóra K.E., Pawelec A.

Oceanological and Hydrobiological Studies

|

2012

|

Vol. 41, No. 3

24-32

EN

Twaite shad Alosa fallax (12 – 48 cm total length) from the Gulf of Gdansk feed on Mysids: Mysis mixta, Neomysis integer, and fish: Sprattus sprattus, Osmerus eperlanus, and Pomatoschistus sp.. In the stomachs of A. fallax there also occur Hydrobia sp., Diptera and small stones, particles of wood and plastic. The food of inshore twaite shad measured from 12 to 21 cm centered on M. mixta. Fish are the main prey for A. fallax from the class length 22 – 31 cm from the Vistula River mouth and for all shads longer than 32 cm.