Claudia Earp

• Dr.
• Project Manager at Goethe University Frankfurt

Divergent selection between ecologically dissimilar habitats promotes local adaptation, which can lead to reproductive isolation (RI). Populations in the Poecilia mexicana species complex have independently adapted to toxic hydrogen sulfide and show varying degrees of RI. Here, we examined the variation in the mate choice component of prezygotic RI...

Stream ecosystems show gradual variation of various selection factors, which can result in a zonation of species distributions and gradient evolution of morphological and life-history traits within species. Identifying the selective agents underlying such phenotypic evolution is challenging as different species could show shared and/or unique (spec...

The teleost brain is an energetically costly organ, which raises the question of how brain anatomy is shaped by divergent ecological factors in contrasting (extreme/resource-limited vs. benign) environments. A previous study compared different ecotypes of the teleost Poecilia mexicana in the Tacotalpa drainage system and found that cave fish had a...

Cavefishes typically evolve sensory adaptations to compensate for the loss of visual orientation and communication in their naturally dark habitats. We compared the response to chemical cues from conspecifics between surface- and cave-dwelling populations of Atlantic mollies (Poecilia mexicana) using dichotomous association preference tests. In one...

Background One aspect of premating isolation between diverging, locally-adapted population pairs is female mate choice for resident over alien male phenotypes. Mating preferences often show considerable individual variation, and whether or not certain individuals are more likely to contribute to population interbreeding remains to be studied. In th...

In the presence of predators, many prey species exhibit immediate behavioral responses like the avoidance of risky areas, which imposes opportunity costs, for instance, in the form of reduced foraging. Thus, prey species should be able to discriminate between different predator types and adjust their response to the imminent predation risk. In our...

Organismen, die vom Menschen geschaffene urbane Lebensräume nutzen können, müssen häufig gesteigerten Stress und hohe Licht-, Lärm-und Luftverschmutzung in Kauf nehmen. Die nötigen Anpassungen, um dennoch als Kulturfolger zu leben, finden sich in der Morphologie und im Verhalten, bei Vögeln insbesondere auch in der akustischen Kommunikation. Anthro...

Artificially heated water bodies represent unusual habitats in temperate regions and form a refuge for exceptional fish communities. The Gillbach, a tributary of the river Erft in Germany, receives thermally polluted cooling water from a power plant. Here, we present data on the composition of the fish community in the Gillbach and found a high abu...

The Cueva del Azufre in Tabasco,Mexico, is a nutrient-rich cave and its inhabitants need to cope with high levels of dissolved hydrogen sulfide and extreme hypoxia. One of the successful colonizers of this cave is the poeciliid fish Poecilia mexicana, which has received considerable attention as a model organism to examine evolutionary adaptations...

Extreme habitats are often characterized by reduced predation pressures, thus representing refuges for the inhabiting species. The present study was designed to investigate predator avoidance of extremophile populations of Poecilia mexicana and P. sulphuraria that either live in hydrogen sulfide-rich (sulfidic) springs or cave habitats, both of whi...

Mate choice copying was mostly described as a strategy employed by females to assess the quality of potential mates, but also males can copy other males’ mate choice. In both cases, focal individuals show an increased propensity to copulate with a potential mating partner they could observe interact sexually with another individual (the ‘model’). S...

Socially influenced mate choice behavior is currently a growing field in the study of sexual selection and evolu-tion. Here, we provide the first description of male Gri-jalva mosquitofish (Heterophallus milleri) courtship behav-ior, and further report on an unparalleled "audience effect" in that species. Lab-reared male Grijalva mosquitofish sig-n...

Mate choice as one element of sexual selection can be sensitive to public information from neighbouring individuals. Here, we demonstrate that males of the livebearing fish Poecilia mexicana gather complex social information when given a chance to familiarize themselves with rivals prior to mate choice. Focal males ceased to show mating preferences...

Extreme environments are often considered a predation refuge for organisms living in them. In southern Mexico several species of poeciliid fishes are undergoing incipient speciation in a variety of extreme (i.e. permanently dark and/or sulphidic) freshwater systems, and previous research has demonstrated reproductive isolation between populations f...

Adaptation to ecologically heterogeneous environments can drive speciation. But what mechanisms maintain reproductive isolation among locally adapted populations? Using poeciliid fishes in a system with naturally occurring toxic hydrogen sulfide, we show that (a) fish from non-sulfidic sites (Poecilia mexicana) show high mortality (95 %) after 24 h...