Jan Heuschele

Jan Heuschele
University of Oslo · Department of Biosciences

PhD

About

57
Publications
8,422
Reads
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1,126
Citations
Introduction
I am currently working at the Department of Biosciences, University of Oslo. I do research in the intersection between Evolutionary, Marine and Behavioural ecology. Current projects include the influence of multiple stressors (LUMS), improving the communication between field, lab and modellers (FILAMO), and 'Sea lice control - a semiochemical approach'.
Additional affiliations
September 2015 - August 2018
University of Oslo
Position
  • PostDoc Position
September 2014 - present
Lund University
Position
  • Visiting Researcher
February 2012 - August 2014
Technical University of Denmark
Position
  • PostDoc Position
Description
  • Chemical ecology of copepods: Research on Crustacean pheromones
Education
August 1997 - May 2003
University of Münster
Field of study
  • Landscape Ecology

Publications

Publications (57)
Article
Copper is both an essential trace element and a potent pesticide. The use of copper as an antifoulant has increased in the last decades in line with the expanding aquaculture and shipping industries. In aquatic environments, it also affects non-target taxa. One of which are copepods, which constitute the central link in the marine food web. Despite...
Article
Full-text available
Harmful algae bloom (HAB) forecasting has developed rapidly over recent decades, but predicting harmful levels of marine biotoxins in shellfish is still a challenge. New discoveries suggest that predator‐prey interactions may be an important driver in the formation of HABs. Key species of harmful algae respond to copepod infochemicals with increase...
Article
Full-text available
Previous experimental studies suggest that the production of sound associated with expelling gas from an open swimbladder may play a role in communication. This would suggest non-random gas release. We used deployed echosounders to study patterns of gas release among a fjord population of sprat ( Sprattus sprattus ). The echosounder records concurr...
Article
Understanding growth and development over ontogeny, and the effects of stressors on life history, requires bioenergetic analysis, for example using models based on dynamic energy budget theory. Such analyses require precise and accurate determination of the animal's biomass or biovolume over time. Automated imaging offers great advantages by allowi...
Article
Traditional ecotoxicology methods involving copepods have focused on exposure of pooled individuals and averaged responses, but there is increasing awareness of the importance of individual variation. Many biological traits are density‐dependent, and decisions to use single‐individual or pooled exposure may affect responses to anthropogenic stresso...
Article
Natural biotic and anthropogenic stressors can interact to alter contaminant toxicity. Energetic restrictions are potential mechanisms causing this pattern. To identify processes underlying observed effects of predation risk and copper (Cu) on delayed copepod age at maturity, we examined how these two stressors affect respiration rates. We tested t...
Article
In ecotoxicology and aquatic ecology, we often ignore responses of individuals and focus on average responses. Yet, both terrestrial and aquatic animals display consistent behavioural differences between individuals. The distribution of behavioural differences within a population contains vital information for predicting population responses to nov...
Article
Copper (Cu) is an essential trace metal, but may also be toxic to aquatic organisms. While many studies have investigated the cytotoxicity of Cu, little is known about the in vivo genotoxic potential of Cu in marine invertebrates. We investigated the genotoxicity of Cu in two pelagic calanoid copepods Acartia tonsa and Temora longicornis and the in...
Article
Individual trait variation is essential for populations to cope with multiple stressors and continuously changing environments. The immense number of possible stressor combinations and the influence of phenotypic variation makes experimental testing for effects on organisms challenging. The acquisition of such data requires many replicates and is n...
Article
To examine whether natural stressors like predation risk affect responses to anthropogenic contaminants, we exposed nauplii of the copepod Tigriopus brevicornis to chemical cues from fish (kairomones) and copper (Cu). We tested effects of these treatments, singly and combined, on copepod age and size at maturity, and development stage sensitivity,...
Article
Full-text available
In the last decades, limnic water bodies in the Northern hemisphere have experienced a noticeable browning, i.e., increasing levels of dissolved organic matter (DOM). While the effects on primary producers is usually considered negative (light attenuation), zooplankton is thought to benefit from increased DOM, which absorbs harmful ultraviolet radi...
Article
The flow regime around a chemically baited trap is crucial for the trapping process and distribution of bait downstream of traps. We measured the flow field downstream of a trap prototype in flume experiments and mapped the distribution of bait using laser induced fluorescence. The trap produced a downstream wake, where flow recirculated towards th...
Article
Collaboration between modellers and experimentalists is essential in ecological research, however, different obstacles linking both camps often hinder scientific progress. In this commentary, we discuss several issues of the current state of affairs in this research loop. Backed by an online survey amongst fellow ecologists, modellers and experimen...
Article
Full-text available
The understanding of consistent individual differences in behavior, often termed “personality,” for adapting and coping with threats and novel environmental conditions has advanced considerably during the last decade. However, advancements are almost exclusively associated with higher-order animals, whereas studies focusing on smaller aquatic organ...
Research
Full-text available
Poster for the "A New Age of Discovery for Aquatic Microeukaryotes" Symposium held at EMBL Heidelberg (26-29 Jan 2016)
Article
Full-text available
The purpose of this dataset was to compile adult and offspring size estimates for marine organisms. Adult and offspring size estimates of 408 species were compiled from the literature covering >17 orders of magnitude in body mass and including Cephalopoda (ink fish), Cnidaria (“jelly” fish), Crustaceans, Ctenophora (comb jellies), Elasmobranchii (c...
Article
Full-text available
Diatoms are highly abundant unicellular algae that often dominate pelagic as well as benthic primary production in the oceans and inland waters. Being strictly dependent on silica to build their biomineralized cell walls, marine diatoms precipitate 240 × 10e12 mol Si per year, which makes them the major sink in the global Si cycle. Dissolved silici...
Data
Diatoms are highly abundant unicellular algae that often dominate pelagic as well as benthic primary production in the oceans and inland waters. Being strictly dependent on silica to build their biomineralized cell walls, marine diatoms precipitate 240 × 10e12 mol Si per year, which makes them the major sink in the global Si cycle. Dissolved silici...
Data
The movie shows the characteristic back and forth movement of Seminavis robusta (strain F2-31B) synonymous to the run-reverse movement of marine bacteria. Movie was accelerated 10x. Time labels denote min:s.
Data
Supplementary Figures 1-4 and Supplementary Tables 1-7.
Data
The movie shows the response of S. robusta (strain F2-31B) to a control bead (no dSi). dSi-starved cells move randomly around the area and show no response towards the bead. The video speed was accelerated 50 times and the scale bar indicates 50 μm. Time labels denote min:s.
Data
The movie shows the attraction and accumulation of Navicula sp. to a dSi-loaded bead for 20 min. Like S. robusta, this pennate diatom also has a back and forth movement. dSi-starved cells also accumulated towards the bead in less than 300s. The video speed was accelerated 50 times and the scale bar indicates 100 μm. Time labels denote min:s
Data
The movie shows the attraction and accumulation of S. robusta (strain F2-31B) to a dSi-loaded bead. dSi-starved cells began to move towards the bead in less than 300s, indicating that they perceived a gradient of dSi diffusing from the bead. The video speed was accelerated 50 times and the scale bar indicates 50 μm. Time labels denote min:s.
Data
The movie shows S. robusta (strain P36 MT+) starved and exposed to a control bead for 1h. No response towards the bead was observed for the whole observation area. The video speed was accelerated 50 times and the scale bar indicates 100 μm. Time labels denote min:s.
Data
The movie shows S. robusta (strain P36 MT+) starved and exposed to a dSi-loaded bead for 1h. Attraction towards the bead for the whole observation time was evident indicating that the created diffusion gradient was stable for 1h. Furthermore, cells were observed to stop moving around ~25 min which was also observed for dSi-starved cells after bulk...
Article
The purpose of this dataset was to compile adult and offspring size estimates for marine organisms. Adult and offspring size estimates of 408 species were compiled from the literature covering >17 orders of magnitude in body mass and including Cephalopoda (ink fish), Cnidaria (“jelly” fish), Crustaceans, Ctenophora (comb jellies), Elasmobranchii (c...
Article
Full-text available
Copepods are ubiquitous in aquatic habitats. They exude bioactive compounds that mediate mate finding or induce defensive traits in prey organisms. However, little is known about the chemical nature of the copepod exometabolome that contributes to the chemical landscape in pelagic habitats. Here we describe the development of a closed loop solid ph...
Data
Alligned peak list showing intensities (peak area) of all measured compounds Alligned peak list from mass spec data. Peak ID in column A, Compound specific mass@retentiontime in column B, and intensities of each compound for each sample in the following columns. below threshold entries denoted as “1”.
Article
Full-text available
Explaining variability in offspring vs. adult size among groups is a necessary step to determine the evolutionary and environmental constraints shaping variability in life history strategies. This is of particularly interest for life in the ocean where a diversity of offspring development strategies is observed along with variability in physical an...
Article
Most animals, including aquatic crustacean zooplankton, perform strong avoidance movements when exposed to a threat, such as ultraviolet radiation (UVR). We here show that the genera Daphnia and Bosmina instantly adjust their vertical position in the water in accordance with the present UVR threat, i.e., seek refuge in deeper waters, whereas other...
Article
Full-text available
Copepods are ubiquitous in aquatic habitats. They exude bioactive compounds that mediate mate finding and induce defensive traits in prey organisms. Little is, however, known about the chemical nature of the copepod exometabolome that contributes to the chemical landscape in pelagic habitats. Here we describe the development of a closed loop solid...
Article
Full-text available
Copepods are ubiquitous in aquatic habitats. They exude bioactive compounds that mediate mate finding and induce defensive traits in prey organisms. Little is, however, known about the chemical nature of the copepod exometabolome that contributes to the chemical landscape in pelagic habitats. Here we describe the development of a closed loop solid...
Article
Full-text available
The size of an individual organism is a key trait to characterize its physiology and feeding ecology. Size-based scaling laws may have a limited size range of validity or undergo a transition from one scaling exponent to another at some characteristic size. We collate and review data on size-based scaling laws for resource acquisition, mobility, se...
Article
The size of an individual organism is a key trait to characterize its physiology and feeding ecology. Size-based scaling laws may have a limited size range of validity or undergo a transition from one scaling exponent to another at some characteristic size. We collate and review data on size-based scaling laws for resource acquisition, mobility, se...
Article
Full-text available
Diel vertical migration (DVM) is a common behavior adopted by zooplankton species. DVM is a prominent adaptation for avoiding visual predation during daylight hours and still being able to feed on surface phytoplankton blooms during night. Here, we report on a DVM study using a Video Plankton Recorder (VPR), a tool that allows mapping of vertical z...
Article
Full-text available
An increasing number of studies show the importance of chemical interactions in the aquatic environment. Our understanding of the role of chemical cues and signals in larger crustaceans has advanced in the last decades. However, for copepods, the most abundant metazoan zooplankton and essential for the functioning of the marine food web, much is st...
Data
Phytoplankton composition in the beginning and the end of the experiment with each taxonomic group presented in μg C L−1. Note the different scale of the y axis between sampling dates
Data
The physical environment in the mesocosms during the experiment, if not otherwise indicate lines indicate the average value over the water column and grey areas indicate confidence limits. O2 concentration measured in µM, PAR in µmol s−1W−1
Article
Full-text available
We studied female fertilization status in North Sea summer populations and labora-tory cultures of the marine copepod Temora longicornis and found fractions of fertilized females in both field and laboratory populations that were much smaller (,50%) than predicted by a theoretical model that assumes random mating. Such low fertil-ization rates are...
Article
Full-text available
Reproduction in planktonic animals depends on numerous biotic and abiotic factors. One of them is predation pressure, which can have both direct consumptive effects on population density and sex ratio, and non-consumptive effects, for example on mating and migration behaviour. In copepods, predator vulnerability depends on their sex, motility patte...
Article
Full-text available
The importance of sexual selection for the evolution, dynamics and adaptation of organisms is well known for many species. However, the topic is rarely studied in marine plankton, the basis of the marine food web. Copepods show behaviors that suggest the existence of sexually selected traits, and recent laboratory experiments identified some select...
Article
Full-text available
Many copepod species rely on pheromone cues to find partners. Some parasitic and benthic copepod males are able to distinguish between females of different reproductive states. Here, we demonstrate that the swimming activity and velocity of males of a pelagic copepod, Oithona davisae, increases in the presence of virgin when compared with mated fem...
Article
Full-text available
Mate choice is one of the main mechanisms of sexual selection, with profound implications for individual fitness. Changes in environmental conditions can cause individuals to alter their mate search behaviour, with consequences for mate choice. Human-induced eutrophication of water bodies is a global problem that alters habitat structure and visibi...
Article
Full-text available
Sexual selection is often assumed to increase the viability of populations by increasing the quality of offspring produced. Presently, human-induced environmental changes are altering the process of sexual selection by influencing male–male interactions and female mate choice. Here, we show that increased density of filamentous algae due to eutroph...
Article
Sexual selection can explain major micro- and macro-evolutionary patterns. Much of current theory predicts that the strength of sexual selection (i) is driven by the relative abundance of males and females prepared to mate (i.e. the operational sex ratio, OSR) and (ii) can be generally estimated by calculating intra-sexual variation in mating succe...
Article
Full-text available
Human-induced environmental changes alter terrestrial and aquatic ecosystems worldwide. This influences also evolutionary processes, such as sexual selection, by constraining mate choice and mate competition. Organisms often use multiple cues in mate choice, with different cues indicating the same or different benefits. Because the assessment and i...
Article
Full-text available
Jordens ekologiska system undergår för tillfället stora förändringar pga. människans aktiviteter. Ett växande antal studier visar att dessa förändringar påverkar naturliga och sexuella urvalet och därmed evolutiva processer. Målet med detta arbete var att undersöka effekterna av omgivningsförändringar på sexuella urvalet genom att använda den ökade...
Article
Full-text available
The role of sexual selection in adaptation is disputed. A balance between sexual and viability selection can be achieved in stable environments, but environmental perturbations could change the costs and benefits arising from sexual selection and influence the rate of adaptation. Here we synthesise theoretical and empirical work on the role of sexu...
Article
Full-text available
Human-induced eutrophication is a serious environmental problem that constrains visual communication and influences the mate choice process in fishes. Eutrophication also changes the chemical environment and the pH of the water, which could influence the use of olfactory cues in mate choice. Here, we show that an increase in pH enhances the use of...