Torbjorn Ekrem

Torbjorn Ekrem
Norwegian University of Science and Technology | NTNU · Department of Natural History

Dr. scient.

About

154
Publications
81,022
Reads
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2,918
Citations
Introduction
I am interested in evolution, systematics and biogeography, in particular of non-biting midges of the family Chironomidae (Diptera). My research focuses on taxonomy, biology, phylogeny, zoogeography and molecular systematics. The last few years I have been involved in various priojects testing and using DNA barcoding in biosystematics. I am also coordinating the Norwegian Barcode of Life network and project (NorBOL), and lead a project on environmental barcoding of aquatic invertebrates (EBAI).
Additional affiliations
August 2006 - February 2015
Norwegian University of Science and Technology
Position
  • Professor (Associate)
August 2003 - April 2004
University of Bergen
Position
  • Professor (Associate)
Description
  • Part time
February 1999 - June 2003
University of Bergen
Position
  • PhD Student

Publications

Publications (154)
Article
Full-text available
Initial analyses of DNA barcode data from Norwegian populations attributed to the water mite Lebertia porosa Thor, 1900 revealed large genetic divergence and potentially cryptic species-level diversity. We used one mitochondrial (COI) and two nuclear markers (18S and 28S) as well as comparative morphological analysis to redefine Lebertia porosa, an...
Poster
Full-text available
Background: Tardigrades are common in most habitats, however few studies have focused on large faunistic survey, specifically on tardigrade diversity in forests. Up to now, only 61 species have been recorded in different types of forest in Norway with an additional 25 found in limnic environments in forests. Although little is known about the ecolo...
Article
Full-text available
The botanical compound rotenone is extensively used to eradicate populations and reduce the negative impacts of freshwater invasive animals. The method is controversial as non-target organisms often are negatively affected, but these effects are highly variable among taxa and may be difficult to monitor on species-level as many invertebrates are ch...
Article
The non-biting midge subfamily Tanypodinae (Diptera: Chironomidae) is species-rich, ecologically diverse, and near-globally distributed. Within the subfamily, aspects of generic and species-level taxonomy remain poorly understood, in particular the validity of assignment of Australian and New Zealand taxa to genera erected for northern hemisphere (...
Article
Full-text available
Conservation strategies centered around species habitat protection rely on species’ dietary information. One species at the focal point of conservation efforts is the herbivorous grouse, the western capercaillie (Tetrao urogallus), which is an indicator species for forest biodiversity conservation. Non-molecular means used to study their diet are t...
Article
Full-text available
Over the last two decades, the use of DNA barcodes has transformed our ability to identify and assess life on our planet. Both strengths and weaknesses of the method have been exemplified through thousands of peer-reviewed scientific articles. Given the novel sequencing approaches, currently capable of generating millions of reads at low cost, we r...
Article
Full-text available
Background. Dragonflies and damselflies (Odonata) are important components in biomonitoring due to their amphibiotic lifecycle and specific habitat requirements. They are charismatic and popular insects, but can be challenging to identify despite large size and often distinct coloration, especially the immature stages. DNA-based assessment tools re...
Preprint
Full-text available
Conservation strategies centred around species habitat protection rely on species dietary information. One species at the focal point of conservation efforts is the herbivorous grouse, the western capercaillie ( Tetrao urogallus ). Traditional microhistological analysis of crop contents or faeces and/or direct observations are time-consuming and at...
Article
Full-text available
DNA barcoding and metabarcoding is increasingly used to effectively and precisely assess and monitor biodiversity in aquatic ecosystems. As these methods rely on data availability and quality of barcode reference libraries, it is important to develop and follow best practices to ensure optimal quality and traceability of the metadata associated wit...
Article
Full-text available
Like meiofauna in general, tardigrades are often neglected in ecological and environmental surveys. Tardigrades occur in all parts of the world, from deep marine sediments to alpine environments, and are present in most ecosystems. They are therefore potentially good candidates for biomonitoring programs. However, sampling of these minute animals i...
Article
Full-text available
As global biodiversity declines, there is an increasing need to create an educated and engaged society. Having people of all ages participate in measuring biodiversity where they live helps to create awareness. Recently, the use of environmental DNA (eDNA) for biodiversity surveys has gained momentum. Here, we explore whether sampling eDNA and sequ...
Article
Biodiversity studies greatly benefit from molecular tools, such as DNA metabarcoding, which provides an effective identification tool in biomonitoring and conservation programmes. The accuracy of species‐level assignment, and consequent taxonomic coverage, relies on comprehensive DNA barcode reference libraries. The role of these libraries is to su...
Preprint
Full-text available
Automated system to assess the quality and reliability of reference libraries
Preprint
Full-text available
Background: As global biodiversity declines, there is an increasing need to create an educated and engaged society. Having people from all ages participate in measuring biodiversity where they live helps to create awareness. Recently, the use of environmental DNA (eDNA) for biodiversity surveys has gained momentum. Here, we test whether sampling eD...
Article
Full-text available
Non-biting midges of the fly family Chironomidae are extremely abundant and diverse in Arctic regions and are essential components of Arctic ecosystems. Modern identification tools based on documented records of Arctic chironomid species are therefore important for ecological research and environmental monitoring in the region. Here, we provide an...
Article
Full-text available
Short, standardized gene fragments for species identification (DNA barcodes) have proven effective in delineating closely-related insect species, and can be critical characters to include in taxonomic studies. This is also the case for the species-rich and widely distributed fly family Chironomidae (non-biting midges). Inspired by observed genetic...
Article
Full-text available
Stormwater ponds are used to compensate for the adverse effects that road runoff might have on the natural environment. Depending on their design and placement, stormwater ponds can act as both refugia and traps for local biodiversity. To evaluate the impact of stormwater ponds on biodiversity, it is critical to use effective and precise methods fo...
Article
Full-text available
Modern high-throughput sequencing technologies are becoming a game changer in many fields of aquatic research and biomonitoring. To unfold their full potential, however, the independent development of approaches has to be streamlined. This discussion must be fuelled by stakeholders and practitioners and, scientific results collaboratively filtered...
Article
Full-text available
Colonisation and immigration history is often neglected as a factor when investigating community or species distribution patterns. However, for dynamic systems that are still reacting to large-scale environmental change, such as the retreat of the ice since the last glacial maximum, colonisation history may explain a large amount of the variation b...
Article
Full-text available
Effective identification of species using short DNA fragments (DNA barcoding and DNA metabarcoding)requires reliable sequence reference libraries of known taxa. Both taxonomically comprehensive coverage and content quality are important for sufficient accuracy. For aquatic ecosystems in Europe, reliable barcode reference libraries are particularly...
Preprint
Full-text available
Effective identification of species using short DNA fragments (DNA barcoding and DNA metabarcoding) requires reliable sequence reference libraries of known taxa. Both taxonomically comprehensive coverage and content quality are important for sufficient accuracy. For aquatic ecosystems in Europe, reliable barcode reference libraries are particularly...
Article
Full-text available
Insects have invaded marine habitats only rarely and secondarily. Recently, we discovered a flightless dipteran species skating rapidly on the surface of seawater ponds at the Pacific coast of eastern China. Morphological analyses initially suggested an isolated position of the non‐biting midge, suggesting the erection of a new genus within Chirono...
Article
Full-text available
Due to their small size and smooth body, members of the figitid genus Alloxysta can be notoriously difficult to identify based on morphology alone. Moreover, several species are suspected to contain brachypterous variants that previously have been described under separate names. We used gene sequences of the mitochondrial gene cytochrome c oxidase...
Article
Full-text available
Chironomid flies (non-biting midges) are among the most abundant and diverse animals in Arctic regions, but detailed analyses of species distributions and biogeographical patterns are hampered by challenging taxonomy and reliance on morphology for species-level identification. Here we take advantage of available DNA barcode data of Arctic Chironomi...
Article
Full-text available
Characterisation of freshwater benthic biodiversity using DNA metabarcoding may allow more cost-effective environmental assessments than the current morphological-based assessment methods. DNA metabarcoding methods where sorting or pre-sorting of samples are avoided altogether are especially interesting, since the time between sampling and taxonomi...
Article
Full-text available
For over a decade, DNA barcoding has proven an effective modern tool in taxonomy, evolutionary biology and biodiversity research. Many new species have been discovered and described with DNA barcodes as part of their diagnostic features. Using DNA barcodes, we uncovered a number of potential species within the Tanytarsus curticornis and Tanytarsus...
Article
Tanytarsus van der Wulp, with 355 currently known valid species, is a comparatively large genus of nonbiting midges (Diptera: Chironomidae). Relationships among Tanytarsus and associated genera and among species in the genus have been exceptionally difficult to resolve using morphology or single gene genealogies. Here, the phylogeny of Tanytarsus s...
Article
Full-text available
Freshwater metazoan biodiversity assessment using environmental DNA (eDNA) captured on filters offers new opportunities for water quality management. Filtering of water in the field is a logistical advantage compared to transport of water to the nearest lab, and thus, appropriate filter preservation becomes crucial for maximum DNA recovery. Here, t...
Article
Full-text available
Taxonomy is a scientific discipline that has provided the universal naming and classification system of biodiversity for centuries and continues effectively to accommodate new knowledge. A recent publication by Garnett and Christidis [1] expressed concerns regarding the difficulty that taxonomic changes represent for conservation efforts and propos...
Article
Full-text available
Over the past decade, molecular approaches to species delimitation have seen rapid development. However, species delimitation based on a single locus, for example, DNA barcodes, can lead to inaccurate results in cases of recent speciation and incomplete lineage sorting. Here, we compare the performance of Automatic Barcode Gap Discovery (ABGD), Bay...
Article
Aquatic biomonitoring has become an essential task in Europe and many other regions as a consequence of strong anthropogenic pressures affecting the health of lakes, rivers, oceans and groundwater. A typical assessment of the environmental quality status, such as it is required by European but also North American and other legislation, relies on ma...
Book
Full-text available
Aquatic biomonitoring has become an essential task in Europe and many other regions as a consequence of strong anthropogenic pressures affecting the health of lakes, rivers, oceans and groundwater. A typical assessment of the environmental quality status, such as it is required by European but also North American and other legislation, relies on ma...
Article
Full-text available
Chironomidae (Diptera) pupal exuviae samples are commonly used for biological monitoring of aquatic habitats. DNA barcoding has proved useful for species identification of chironomid life stages containing cellular tissue, but the barcoding success of chironomid pupal exuviae is unknown. We assessed whether standard DNA barcoding could be efficient...
Article
Full-text available
Micromoths can be challenging to identify based on morphology and are frequently omitted in assessments of moth diversity. However, their species richness and biology make them important components of terrestrial ecosystems. In this study we identified 1227 micromoths from a suburban garden at 63° north using DNA barcoding of Malaise trap samples....
Article
Full-text available
The protection, preservation and restoration of aquatic ecosystems and their functions are of global importance. For European states it became legally binding mainly through the EU-Water Framework Directive (WFD). In order to assess the ecological status of a given water body, aquatic biodiversity data are obtained and compared to a reference water...
Article
Full-text available
During our work on the Chironomidae chapter of the forthcoming Manual of Afrotropical Diptera we examined type material of the four Chironomini species Chironomus (Endochironomus) hamatus, Chironomus (E.) pruinosus, Chironomus (E.) woodi and Chironomus (Cryptochironomus) inflexus described by Paul Freeman. We provide photos of the types and associa...
Article
Full-text available
The chiefly Holarctic Hydrobius species complex (Coleoptera, Hydrophilidae) currently consists of H. arcticus Kuwert, 1890, and three morphological variants of H. fuscipes (Linnaeus, 1758): var. fuscipes, var. rottenbergii and var. subrotundus in northern Europe. Here molecular and morphological data are used to test the species boundaries in this...
Article
Maternal inheritance via the female-specific W chromosome was long ago proposed as a potential solution to the evolutionary enigma of co-existing host-specific races (or 'gentes') in avian brood parasites. Here we report the first unambiguous evidence for maternal inheritance of egg colouration in the brood-parasitic common cuckoo Cuculus canorus....
Data
Supplementary Figures 1-2, Supplementary Tables 1-10 and Supplementary References