Facultative paedomorphosis in a population of Lissotriton vulgaris (Amphibia: Salamandridae) from the Danube Delta Biosphere Reserve (Romania)

Facultative paedomorphosis refers to the simultaneous expression of 2 different phenotypes (i.e. paedomorphic and metamorphic) within the same population. Over the last 6 decades, this phenomenon was reported from only 5 populations of smooth newt Lissotriton vulgaris (Linnaeus, 1758) in Romania. In the spring of 2011, we found a new facultative paedomorphic population. The sample was female-biased, thus suggesting a sex-dependent expression of the paedomorphic phenotype. Most of the populations recorded in Romania were found in permanent water bodies with abundant vegetation.