SFB-TRR 212

Life history implications of the mother's choice for a larval habitat: niche choice and niche conformance in the Fire Salamander

Individual niches change over lifetime due to developmental, social or environmental changes. This is especially noticeable in species, in which developmental changes, such as metamorphosis, require the conformation to different niches during ontogeny. For example, the Fire Salamander (Salamandra salamandra) with its biphasic life cycle switches its habitat from completely aquatic to terrestrial once being metamorphosed. In addition to the niche change after metamorphosis, female Fire Salamander of our study population can choose between two different larval deposition habitats (stream and pond). Population genetic studies have shown that two genetic clusters exist, representing the two ecological habitats. Assortative mating is supposed to be the driving force for the maintenance of the two genetic (habitat specific) clusters, with females found at ponds being more likely to mate with genetic pond type males and females found at first-order streams to be more likely to mate with stream type males. Only females can be seen at the larval deposition habitats and mating occurs temporary as well as spatially separated from the time and habitat females use for larval deposition. This gives the unique possibility to investigate whether and how individuals choose a niche for their offspring and the consequences of that choice.

1. Using a classical match-mismatch design, in which larvae deposited into streams will be transferred into ponds and vice versa, I will investigate whether individual larvae conform to the given niche, which is chosen by their mothers and whether individuals differ in niche conformance.
2. Focussing on fitness relevant traits, such as skin colour pattern, skin microbes, the chemical phenotype and the immune function of individual larvae I will additionally investigate the impact of the larval habitat on the adult phenotype and
3. how information about the larval habitat is transferred onto the postmetamorphic phenotype. This will gain knowledge about the underlying mechanisms of the female's niche choice for their larvae.
4. Lastly this proposal aims to gain knowledge about the underlying mechanism of female mate choice and the cues by which females are able to distinguish between males of the two habitat specific genotypes.