For the purpose of reproduction most amphibians require fresh wateralthough some lay their eggs on land and have developed various means of keeping them moist. A few (e.g. Fejervarya raja) can inhabit brackish water, but there are no true marine amphibians.[66] There are reports, however, of particular amphibian populations unexpectedly invading marine waters. Such was the case with the Black Sea invasion of the natural hybrid Pelophylax esculentus reported in 2010.[67]