New alien species recorded in the Polish Baltic


The latest issue of „Oceanologia” reports on records of a North American annelid Limnodrilus cervix i and Ponto-Caspian cladoceran Evadne anonyx.

A single individual of Limnodrilus cervix was recorded in a sample collected in 2010 in the Vistula Lagoon. Other European records are from Great Britain, the Netherlands, Belgium, Sweden and Romania. The species was probably accidentally introduced from one of these countries in ships’ ballast waters. Introduction directly from natrural range in North America is less likely. Except for Great Britain, where Limnodrilus cervix is abundant, there are no records of invasiveness of this species in Europe.

The earliest records of Evadne anonyx in Poland were in 2006 in the Gulf of Gdańsk, that is, 7 years after the first Baltic record of the species from the Gulf of Tallin. Since their discovery, the populations in the Gulf of Gdańsk were numerous and included all developmental stages.