Michael Heethoff

Michael Heethoff
Technische Universität Darmstadt | TU · Animal Evolutionary Ecology

Prof. Dr. rer.nat.

About

217
Publications
39,953
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2,091
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Introduction
I'm a zoologist interested in the evolution and ecology of insects and chelicerates.
Additional affiliations
November 2013 - present
Technische Universität Darmstadt
Position
  • Researcher
April 2012 - October 2013
University of Tuebingen
October 2010 - March 2012
Karl-Franzens-Universität Graz

Publications

Publications (217)
Article
Full-text available
Cyanogenesis denotes a chemical defensive strategy where hydrogen cyanide (HCN, hydrocyanic or prussic acid) is produced, stored, and released toward an attacking enemy. The high toxicity and volatility of HCN requires both chemical stabilization for storage and prevention of accidental self-poisoning. The few known cyanogenic animals are exclusive...
Article
Full-text available
Compositional data are commonly used in chemical ecology to describe the biological role of chemical compounds in communication, defense or other behavioral modifications. Statistical analyses of compositional data, however, are challenging due to several constraints (e.g., constant sum constraint). We use an ontogenetic series of defensive gland s...
Article
Full-text available
Morphological and chemical defences are widespread anti-predator mechanisms in most domains of life, and play an important role in understanding predator–prey interactions. Classical concepts of dynamical protection (‘inducible defence’) include the morphological changes in certain crustaceans or the production of chemicals in many plants. Permanen...
Article
Full-text available
There is a long-standing controversial about how parthenogenetic species can be defined in absence of a generally accepted species concept for this reproductive mode. An integrative approach was suggested, combining molecular and morphological data to identify distinct monophyletic entities. Using this approach, speciation of parthenogenetic lineag...
Article
Climate change is enhancing the annual mean temperature and the risk for droughts and natural disasters. Hot and dry summers not only have a negative impact on forest performance, but also affect fundamental ecosystem processes such as litter decomposition and nutrient cycling and the organisms involved. Oribatid mites are sexually or parthenogenet...
Article
Full-text available
Intensive land use has been shown to alter the composition and functioning of soil communities. Due to their low dispersal ability, oribatid mites are particularly vulnerable to land-use intensification and species which are not adjusted to management-related disturbances become less abundant. We investigated how different land-use parameters in fo...
Article
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We present Biomedisa, a free and easy-to-use open-source online platform developed for semi-automatic segmentation of large volumetric images. The segmentation is based on a smart interpolation of sparsely pre-segmented slices taking into account the complete underlying image data. Biomedisa is particularly valuable when little a priori knowledge i...
Article
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Temperature influences all biochemical and biophysiological processes within an organism. By extension, it also affects those ecological interactions that are mediated by gland-produced chemical compounds, such as reservoir-based chemical defense. Herein, we investigate how environmental temperature affects the regeneration of defensive secretions...
Article
Full-text available
The ability to synthesize simple aromatic compounds is well known from bacteria, fungi and plants, which all share an exclusive biosynthetic route—the shikimic acid pathway. Some of these organisms further evolved the polyketide pathway to form core benzenoids via a head-to-tail condensation of polyketide precursors. Arthropods supposedly lack the...
Article
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The fatty acid (FA) composition of lipids in animals is influenced by factors such as species, life stage, availability and type of food, as well as the ability to synthesize certain FAs de novo. We investigated the effect of starvation on the neutral lipid (NLFA) and phospholipid (PLFA) fatty acid patterns of the oribatid mite Archegozetes longise...
Article
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One of the largest species in its genus, Odontomachus davidsoni Hoenle, Lattke & Donoso, sp. nov. is described from workers and queens collected at lowland forests in the Chocó-Darién bioregion in coastal Ecuador. The workers are characterized by their uniform red coloration, their large size (16–18 mm body length), and their frontal head striation...
Article
Full-text available
Numerous animal species use defense mechanisms such as chemical secretion to defend against attacks of predators. Although defense mechanisms have the potential to considerably change the dynamics and stability of a system, few theoretical studies exist. In this paper, we focus on predator-prey systems with reservoir-based chemical defense, which i...
Article
Food webs in soil differ fundamentally from those above ground; they are based on inputs from both living plants via root exudates, and from detritus, which is a complex mixture of fungi, bacteria and dead plant remains. Trophic relationships are difficult to disentangle due to the cryptic lifestyle of soil animals and inevitable microbial contribu...
Conference Paper
The rove beetle genus Stenus has experienced a tremendous radiation, comprising > 3000 species widely distributed throughout the world. Its evolutionary success can be partly attributed to specific morphological features, two of which will be in the focus of this contribution: (1) the labium, or lower lip, is modified into a prey-capture apparatus...
Article
Full-text available
Background Trait based functional and community ecology is en vogue. Most studies, however, ignore phenotypical diversity by characterizing entire species considering only trait means rather than their variability. Phenotypical variability may arise from genotypical differences or from ecological factors (e.g., nutritionally imbalanced diet), and t...
Article
Full-text available
Size scaling phenomena occur on different levels, from organisms to ecosystems. In predictive ecology, empirical data on body size relation have been used for decades to explain large-scale temporal and spatial patterns. More recently, community ecologists have started to use abundance-weighted mean body sizes as a tool to predict changes in specie...
Article
Full-text available
Background The use and partitioning of trophic resources is a central aspect of community function. On the ground of tropical forests, dozens of ant species may be found together and ecological mechanisms should act to allow such coexistence. One hypothesis states that niche specialization is higher in the tropics, compared to temperate regions. Ho...
Data
Table S3. Principal component analysis and Envfit of ant species × baits × NLFAs in Brazil and Germany.
Data
Fig. S1. Incidence of ant species in baits and pitfalls in Brazil (a) and Germany (b). Incidence means the number of sample points where a species was recorded using each method. The dashed lines indicate similar expected incidences, taking into account the total number of incidences for each method (mBR = 1.4, mGE = 0.8).
Data
Table S2. SIMPER analysis for ant fatty acids in Brazil and Germany. NLFAs are ordered by decreasing contribution towards dissimilarity between sites (Bray-Curtis). Asterisks indicate statistically significant differences.
Data
Table S1. Incidence of species recorded in this work and labels used in plots.
Article
Full-text available
Background Oribatid mites are among the primordial decomposer faunal elements and potential prey organisms in soil. Among their myriad morphological defenses are strong sclerotization and mineralization, cuticular tecta, and the “ptychoid” body-form, which allows to attain an encapsulated, seed-like appearance. Most oribatid mites possess a pair of...
Article
Full-text available
Oribatid mites are abundant and diverse decomposers in almost all terrestrial microhabitats, especially in temperate forests. Although their functional importance in the decomposition system in these forests has been investigated, spatio-temporal patterns of oribatid mite communities inhabiting different microhabitats have largely been neglected. T...
Data
Species abundances (individuals/kg dry weight) in the microhabitats moss, dead wood (dw) and litter from January to December 2016
Data
Humidity niche of 55 oribatid mite taxa Numbers in brackets indicate the months of occurrence. Symbols denote means, while error bars stand are the standard deviation (SD). Red line indicates the annual mean air temperature. Asterisks indicate different significant levels: *, P < 0.05, **, P < 0.01; ***, P < 0.001.
Data
Statistical results of the temperature occurrence niche analysis μi(ϑ), environmental occurrence niche for air temperature; SD, standard deviation of μi(ϑ).
Data
Statistical results of the humidity occurrence niche analysis μi (RH), environmental occurrence niche for air humidity; SD, standard deviation of μi (RH).
Data
Dry weights (gram) for ten replicates of dead wood, moss and litter from January to December 2016
Article
Full-text available
Digitization of natural history collections is a major challenge in archiving biodiversity. In recent years, several approaches have emerged, allowing either automated digitization, extended depth of field (EDOF) or multi-view imaging of insects. Here, we present DISC3D: a new digitization device for pinned insects and other small objects that comb...
Article
Full-text available
The parthenogenetic trhypochthoniid oribatid mite Archegozetes longisetosus serves as a model organism. Numerous studies have investigated different aspects of its life history and nutritional biology, yet several results remain contradictive. To clarify effects of nutrition on life history parameters, we set up a large scale experiment with ten fo...
Article
Full-text available
Most oribatid mites are opportunistic feeders with a broad variety of different food sources. However, preferences for certain food such as dark pigmented fungi, led to the 'choosy generalist'-hypothesis. The mechanisms behind this idea and whether oribatid mites have an innate or learned preference for food are unknown. We used Archegozetes longis...
Article
Full-text available
This study investigates sex ratios of oribatid mite species and oribatid mite assemblages in different forest microhabitats (dead wood, grass sod, moss, lichen litter, tree bark) to identify possible factors driving sex ratio dynamics. We considered 46,320 individuals belonging to 47 species, and analyzed data on numbers of sexual and parthenogenet...
Article
Full-text available
Diplo-diploid parthenogenesis (thelytoky) is a widespread phenomenon in the mite taxon Sarcoptiformes, and is unusually frequent in the suborder Oribatida, where it characterizes almost 10% of extant species, including whole genera and families. Based on molecular and cytological data, terminal fusion automixis with an inverted meiotic sequence bas...
Article
Full-text available
Reservoir-based chemical defense (= reducible defense) is a widespread mechanism to repel predators in many invertebrates. We investigated the influence of macronutrients on the availability and regeneration of defensive secretions and parametrize a theoretical functional response model for reducible defense to predict nutritional effects on predat...
Chapter
Modern applications for analysing 2D/3D data require complex visual output features which are often based on the multi-platform OpenGL® API for rendering vector graphics. Instead of providing classical workstations, the provision of powerful virtual machines (VMs) with GPU support in a scientific cloud with direct access to high performance storage...
Article
Full-text available
At the basis of a trophic web, coprophagous animals like dung beetles (Scarabaeoidea) utilize resources that may have advantages (easy gain and handling) as well as drawbacks (formerly processed food). Several studies have characterized the nutrients, e.g. C/N ratios and organic matter content, for specific types of dung. However, a comparative app...
Conference Paper
Full-text available
Beamtime and resulting SRμCT data are a valuable resource for researchers of a broad scientific community in life sciences. Most research groups, however, are only interested in a specific organ and use only a fraction of their data. The rest of the data usually remains untapped. By using a new collaborative approach, the NOVA project (Network for...
Article
Biomarkers (e.g. fatty acids, amino acids, stable isotopes, and molecular barcodes) have become increasingly important for investigating food web structure and nutrient flow in soil ecosystems. While the biomarker function of fatty acids has been investigated for some soil animal taxa (e.g. collembolans and nematodes), their role in soil-dwelling o...