EN
This paper describes the current species composition of the genus Gammarus in Puck Bay (western Gulf of Gdańsk, Poland).Sa mples were taken at 9 shallow (ca 0.4 m deep) and 4 deeper (ca 10 m) stations from April 1997 to March 1998. Six Gammarus species were recorded. Gammarus salinus was the most numerous, making up 34.95% of the total of identified amphipod specimens. This species was common throughout the bay but rarely predominant. G. zaddachi (34.75%) was dominant in the northern part of the bay from January to April and was found in almost 2/3 of samples.Less numerous were G. oceanicus (19.15%), common in the southern and eastern parts of Puck Bay, and G. duebeni (9.85%), prevalent in shallow and rocky locations. G. inequicauda and G. locusta made up only 1.13% and 0.12% of the total amphipod material respectively. The species composition of the genus varied considerably not only from one sampling locality to another but also from season to season.I t is possible that two species (G. locusta and G. inequicauda) are currently withdrawing from Puck Bay.