The main aim of this proposal is to further develop Nordic collaborative efforts and exchange of ideas in the study of evolutionary ecology of gobies. Several species of Nordic gobies have proven to be very successful as models in studying questions in be havioural and evolutionary ecology. Notably, several of the internationally leading labs using gobiid fishes as models in this field currently reside within the Nordic countries. This network consists of these research groups - five labs from Norway, Swed en and Finland. These labs have contributed significantly at the forefront of international science in research on mating systems and reproductive ecology. The project include organisation of a Nordic goby meeting, facilitation of the mobility of research ers, post docs and students within the network, as well as planning and collection of basic data on the reproductive ecology of some of our most common gobies from the Baltic to Norway. This will give important information and serve as a basis for future focussed studies and experiments making use of the unique opportunities provided by natural environmental variation in Nordic marine habitats.