PD Dr. Alexander Kupfer

Herpetology

Integrative herpetology

Herpetology is a discipline of zoology focusing on amphibians (caecilians, frogs and salamanders) but also on “reptiles” (turtles, crocodilians, amphisbaenians, lizards, snakes and sphenodontids). Herpetology usually refers to existant species of amphibians and reptiles, whereas paleoherpetology focuses on fossil taxa.

Today’s research in herpetology is interdisciplinary and integrates ecology, morphology, evolutionary biology and phylogeny among other disciplines of zoology. Various approaches and methods such as scanning electron microscopy, CT-scanning, histochemistry, stable isotope analysis, determination of paternity using molecular tools and comparative phylogenetic analysis are applied.

Collections based research at the SMNS is a key to successfully run the research.

Evolutionary reproductive biology

No other group of tetrapods has evolved such an extraordinary diversity of reproductive modes and parental care as amphibians. Among them one particular group, caecilians show a fascinating and unique combination of biological characteristics that provide an excellent foundation for studies in evolutionary reproductive biology. Burrowing vertebartes such as caecilian amphibians inhabit leaf litter and soil ecosystems in forests in tropical environments but are also abundant in tropical agro-ecosystems. The reproductive biology of caecilians is especially fascinating, because they show a significant diversity of reproductive modes including oviparity and viviparity, associated with both parental care and a high degree of parental investment. Among the parental care strategies, skin feeding stands out as a novel system of parental investment. Mothers of certain caecilians, such as Boulengerula taitanus and Siphonops annulatus, nurse their offspring by feeding them their hypertrophied skin. The young bear a highly specialised dentition that makes it possible for them to tear off the skin successfully (for further details see e.g. Nature 440: 926-929 or watch a video on BBC). Important aspects of the research are the evolution of parental care and reproductive modes in caecilians. In a related project, Susanne Kühnel explored the evolutionary morphology of caecilian genitalia (see VolkswagenStiftung for details).

Amphibian systematics

Currently my research focus in amphibian systematics is on South-East-Asian caecilians (Ichthophiidae). Although Ichthyophiids are the second largest caecilian family  (> 50 species), species identification is based on a limited set of diagnostic characters. A serious validation of characters present in different ontogenetic stages including the larval forms (ichthyophiids have a biphasic life cycle) would help resolving the enigma of South-East-Asian caecilian biodiversity.

Evolution of life histories and sexual size dimorphism

How are morphology, life history and ecology connected in the evolution of amphibian mating systems? For example salamanders show a huge diversity of mating systems, i.e. favour either aquatic or terrestrial reproduction, breed either in lotic or in lentic waters, and exhibit various interspecific trade-offs between reproductive parameters. Several lineages show either a male- or a female-biased sexual size dimorphism (SSD). Both individual species and larger clades (and comparative phylogenetic analyses) are used to test several hypotheses regarding evolutionary transitions in reproductive biology. Sandy Reinhard analysed some evolutionary scenarios of SSD patterns in selected amphibian taxa such as salamandrids and caecilians. Currently Peter Pogoda investigates the evolutionary history of phylogenetically basal salamandrids with a special emphasis on SSD.