Gammarus tigrinus was first recorded in the Netherlands in 1960 and has spread rapidly since. In 16 of 18 lakes sampled in the Frisian lake district, G. tigrinus was the dominant gammarid. G. pulex was found in 6 lakes, and G. duebeni in 1 lake. G. tigrinus has now largely replaced the former gammarid faunas of the Frisian lake district .