Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 21

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych:  non-indigenous species
help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
The present paper reports on the occurrence of Hemimysis anomala G.O. Sars, 1907 (Crustacea, Mysidacea) in the coastal waters of the Gulf of Gdańsk in the years 2002–2005.
Oceanologia
|
2010
|
tom 52
|
nr 1
147-151
New data on the distribution of the invasive Ponto-Caspian species, Cercopagis pengoi, in the Gulf of Gdańsk are presented. The species, recorded in 2006, for the first time occurred continuously throughout the summer (July–August) at stations situated in the eastern and western parts of the gulf.
Exotic species of acipenserid fishes have been frequently encountered in the commercial catches of the Baltic Sea, since the early 1990s. Such sightings are rarely reflected as published records. The present paper provides detailed descriptions of two specimens of Russian sturgeons, Acipenser gueldenstaedtii caught in the Exclusive Polish Economic Zone of the Baltic Sea.
Oceanologia
|
2010
|
tom 52
|
nr 2
281-297
Until recently only two palaemonid species inhabited the southern Baltic: Palae- mon adspersus and Palaemonetes varians. Soon after the year 2000 a new species – Palaemon elegans – arrived and quickly established itself as a new component in the trophic web. The objects of this research were to define the energy value and energy resources of P. elegans and to compare them with the corresponding values for the native P. adspersus. These parameters will supply information about this new link in the trophic web and may help to explain the part played by the new prawn and its population in the energy flow. This work demonstrated that the energy values of both prawn species were very much the same: the average energy value of P. elegans was 16.5±2.1 J mg−1 DW (19.3 ± 2.5 J mg−1 AFDW) (N = 150), that of P. adspersus was 16.7 ± 2.1 J mg−1 DW (19.5 ± 2.5 J mg−1 AFDW) (N= 71). No statistically significant differences in energy value were found between the two species with respect to sex, size or season. The results show that P. elegans is an energetically valuable food item for predators. Its energy resources in Polish brackish coastal waters can be as high as 150 kJ m−2; the highest among the palaemonid species in this area, they constitute a rich supply of food for other organisms.
In 2007–2008 the pink salmon, Oncorhynchus gorbuscha, was observed to attempt spawning migration up the Revelva River. The possibility of natural spawning of this alien species in rivers and lakes of Spitsbergen, as well as the risk of its natural hybridization with the native Arctic charr, Salvelinus alpinus, are discussed.
This communication reports on the occurrence of non-indigenous gammarid species of Ponto-Caspian and of North American origin – in the lower course of the River Vistula, in its Delta and in the Vistula Lagoon.
A second record of the small Indo-Pacific fish Tylerius spinosissimus (Tetraodontidae) (known as spiny blaasop) was documented at the beginning of 2009 in the waters of Rhodes Island (south-eastern Aegean Sea, Greece). The finding shows the putative establishment of a population of this alien fish in the Mediterranean with a centre the Dodecanese plateau.
The barred knifejaw, Oplegnathus fasciatus (Temminck et Schlegel, 1844), a species native to the North Western and Eastern Central Pacific, is recorded from the central Mediterranean for the first time. Two individuals were photographed within a month of each other in Grand Harbour and in Marsamxett Harbour, Malta. It seems likely that the fish were introduced by shipping and different scenarios how this may have happened are discussed.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.