Permits
Orsinigobius croaticus is legally protected by law as an endangered taxon in Croatia (Official Gazette of the Republic of Croatia, 2016). In addition, it is an endemic species with very limited distribution. As a result, the number of individuals employed in the laboratory experiments was kept to a minimum (less than 15) to prevent possible effects on the natural population of this species. The sampling by electrofishing for scientific purposes in the natural habitat was approved by the Ministry of Agriculture (permit number 525-13/0545-19-2), while all laboratory experimental protocols were approved by the Bioethics and Animal Welfare Committee of the Faculty of Science, University of Zagreb (permit number 251-58-10617-21-147).