Research

Project Details:
Oophaga pumilio, better known as the strawberry frog, belongs to the family of poison dart frogs (Dendrobatidae). These tiny tropical frogs are immediately recognizable by their intense coloration. Within the species O. pumilio, there is pronounced color polymorphism, expressed in a wide range of skin colors and patterns. Cryptic individuals usually have a green, inconspicuous coloration, while aposematic individuals are characterized by bright colors ranging from intense red to brilliant yellow. The color intensity of O. pumilio thus plays a central role in predator defense, and further studies have shown different colors to play a role in mate selection. It is also known that the color receptors in the retina enable the frogs to distinguish between the color morphs and that carotenoid pigments play a central role in the expression of coloration. Carotenoids are fat-soluble pigments that are responsible for pink, red, orange, and yellow coloration. Since O. pumilio cannot produce carotenoids itself, it must obtain them from animal prey. After ingestion, the carotenoids are absorbed in the gastrointestinal tract, metabolized, and then stored in the skin and other organs, such as the eyes. As part of a feeding experiment, the frogs will be supplemented with carotenoids to determine the influence of these pigments on skin coloration and to gain a better understanding of color development in O. pumilio.
The natural range of O. pumilio includes western Panama, the Caribbean coast of Costa Rica, and parts of Nicaragua. The species inhabits tropical rainforests with dense vegetation and is often observed at forest edges near the coast. Given their average body weight of around half a gram, the question remains as to how these small animals orient themselves in the complex structures of dense rainforests in their territories of several square meters. To answer this question, two independent behavioral experiments will be conducted to investigate the spatial learning behavior of Oophaga pumilio using visual signals that differ in coloration.

Funding: Alexander-von-Humbold-Stiftung, 9.200 EUR

Project Details:
Our study will align with the high priority topics for research identified by WHO in 2023. It will shed light on alternative treatment options for Salmonella infections, address the global challenge of antimicrobial resistance, and provide valuable insights for future research and advancements in the field.
The outcome of this study will be a phage-based treatment strategy, comprising product that I can evaluate through animal trials on chickens in Iran.

Results:

Nutrient-media dependent antimicrobial effects of Limosilactobacillus reuteri and Lactobacillus casei against Salmonella Enteritidis Shakeri G., Batman S.G. , Peh E. , Plötz M. , Kittler S., VAAM 2026, 22.3.-25.3.2026, Berlin, Germany (Poster)

Funding: Fritz-Ahrberg-Stiftung, 15.000 EUR

Project Details:
Embryonic muscle formation (myogenesis) gives rise to the various skeletal muscles of the body. Depending on their function, these muscles have different proportions of the various muscle fibre types after the animals are born. This also means that, as studies on pigs, for example, show, the muscles undergo different biochemical changes during meat maturation after the animals have been slaughtered. Research often focuses on the back muscle (Musculus (M). longissimus dorsi), which, however, is not representative of the entire musculature of the slaughtered animal, as has been shown in pigs. For this reason, in addition to the longissimus muscle, other muscles from the front and hindquarters of cattle are obtained in this project and characterised in terms of their physicochemical properties (e.g. pH, colour) before being packaged as fresh meat in a modified atmosphere. At the end of the storage period, this meat is examined physicochemically and microbiologically and then processed into raw sausages. The latter are also analysed physicochemically and microbiologically during the storage period. For comparison, these tests are also carried out on various turkey muscles, as poultry meat is also very important in meat consumption.

Funding: Nationalparkverwaltung Niedersächsisches Wattenmeer, Wilhelmshaven , 45.063 EUR

Project Details:
The aim of the project is a survey of the local grey seal population in the entire Lower Saxony and Hamburg Wadden Sea during the birthing season (November-December) 2025 and at the time of the fur change (March-April) 2026.
On five trilaterally coordinated dates (three during the birthing season; two during the fur-change period), airborne surveys will be conducted with a single-engine aircraft. During the aerial surveys of the tidal flats, a high-resolution SLR camera will be used to photograph the haul-outs. In order to determine the number of young born as well as the total population, the photos taken are subsequently analyzed on the computer.

Project Details:
Preclinical investigations of the anticonvulsant efficacy range of azetukalner

Funding: Evangelisches Studienwerk Villigst, 44.500 EUR

Project Details:
Pre-clinical investigations of the anticonvulsant efficacy of a specific MAGL inhibitor

Project Details:
Blutchemische SDMA-Bestimmungen

Cooperation Partners:

LABOKLIN - Fachlabor für veterinärmedizinische Diagnostik

Project Details:
Few standardized studies are available on the effect of slow-release GnRH agonists in avian patients. With this background, the aim of this study is to examine the influence of deslorelin, a slow-release GnRH agonist, on the gonadal activity of female and male budgerigars in order to optimize the clinical use of this drug. The activity of the gonads will be examined, for example, by determining the sex hormones and by radiographic assessment of the reproductive organs.

Funding: University of Glasgow, 8.400 EUR

Project Details:
The ears of 15 long-finned pilot whales (Globicephala melas) that mass stranded on July 2023 and on July 2024 in Scotland were collected and fixed during the comprehensive post-mortem examination. They were subsequently sent to ITAW for inner ear analysis. Several complementary analysis techniques will be used to evaluate the ears, depending on the preservation status of the sample. Specifically, techniques optimized in cetaceans such as scanning electron microscopy or immunofluorescence (and histopathology for the less fresh individuals) will be performed to determine whether an animal suffered a hearing loss. With scanning electron microscopy it is possible to observe evidence of lesions within the sensory cells at very high resolution, which can be distinguished from post-mortem decomposition artifacts. On the other hand, with the immunofluorescence technique that we have implemented for ears of marine mammals, we can use a combination of several markers to label the sensory cells and associated neurons at the same time. In addition, we can distinguish between newly formed lesions (that could be associated to the stranding) from old ones. Finally, histopathology is ideal to detect hemorrhages and infections that could have impaired the hearing of the animal, as well as the evaluation of the spiral ganglion neurons, which are the neurons that bring the auditory information from the inner ear to the brain. Hearing impairment can be caused by several factors, including noise exposure, age, ototoxic drugs exposure, pollutants, infections, and congenital disorders. If cases of hearing loss are found, we will evaluate which could be the most likely causes. Including the inner ear collections and analysis within the post-mortem examination protocol in stranded cetaceans (and mass stranded, even if the logistics associated are even more challenging) is essential to detect potential cases of hearing loss, which is particularly relevant in cetaceans that use hearing for all their vital activities.

Project Details:
Overall statistics covering the last 20 breeding years to investigate influences and correlations between maternal, paternal, gender health, genetic and environmental factors and their impact on reproductive performance.

Cooperation Partners:

Deutscher Galopp e.V., Köln