evengar

• Eliassen, Lasse Krøger; Garvang, Even Sletteng; Andersen, Tom; Riemann, Lasse & Titelman, Josefin (2026). Metabarcoding and biomass quantification reveal seasonal parasite associations in copepods. Limnology and Oceanography. ISSN 0024-3590. 71(2). doi: 10.1002/lno.70327. Fulltekst i vitenarkiv Vis sammendrag

  Abstract Parasites are important members of ecosystems, and recent metabarcoding efforts have revealed an abundance of microbial eukaryotic parasites in copepods. However, a putative linkage to host community biomass and composition has not been addressed. We performed zooplankton tows monthly for 2 yr at five stations in the Oslofjord, Norway. The samples were cleared of larger, non‐copepod zooplankton and contained mainly copepods and are henceforth referred to as copepod community samples. Metabarcoding was used to detect microbial eukaryotic parasites in the copepod community samples. We also metabarcoded water samples from one of the stations. Copepods were identified and their biomasses were estimated at three of the stations for 1 yr. Calanus spp. dominated biomass in winter, whereas Temora longicornis and other smaller, short‐lived coastal copepods prevailed during summer. Seasonality in the copepod community was less apparent in the deep waters (200 m) where larger, long‐lived copepods abound. The alveolate parasites Hematodinium and Chromidina were detected at most stations throughout the year and occupied a large proportion of the total reads. Although the microbial eukaryotic community in the copepod community samples reflected the seasonal copepod dynamics, common alveolate parasites (e.g., Syndinium , Blastodinium , and apostome ciliates) appeared year‐round. Co‐occurrence analysis suggested several pair‐wise associations between taxa of microbial eukaryotes and copepods. Parasites are a universal component of copepods in this fjord system and seem well‐adapted to seasonal fluctuations in host community composition. We hypothesize that the parasites may have host ranges that incorporate perennial copepods to maintain their presence in seasonally fluctuating environments.

• Garvang, Even Sletteng; Heuschele, Jan David; Konestabo, Heidi Sjursen; Andersen, Tom; Riemann, Lasse & Titelman, Josefin (2025). Parasite infection shapes the pathobiome and behavior of marine zooplankton. Limnology and Oceanography Letters. 11(1). doi: 10.1002/lol2.70078. Fulltekst i vitenarkiv Vis sammendrag

  When assessing the total impact of disease in a host, it is important to consider not only the disease‐carrying agent but also all symbionts, as they affect and are affected by the course of disease. This concept of a pathobiome is increasingly recognized in disease ecology, but is not well‐investigated in natural systems. Copepods are key organisms in marine ecosystems and host a variety of symbionts, including bacteria and eukaryotic parasites. We investigated the impact of a taxonomically uncertain yellow‐hyphal parasite (YHP) on its copepod host Calanus helgolandicus with an incubation experiment, comparing survival, behavior, and microbiomes of uninfected and infected hosts. Infected hosts suffered higher mortality, and altered behavior which can increase predation risk. The microbiomes differed between infected and uninfected hosts, likely caused by a combination of direct effects of infection, and environmental effects driven by parasite‐induced behavioral change. We identified several potential contributing taxa to the Calanus ‐YHP pathobiome using model‐based ordination.

• Garvang, Even Sletteng; Eliassen, Lasse Krøger; Titelman, Josefin & Andersen, Tom (2024). Outbreak conditions and impacts of parasites in copepod populations. Ecosphere. 15(12), s. 1–18. doi: 10.1002/ecs2.70093. Fulltekst i vitenarkiv
• Eliassen, Lasse Krøger; Garvang, Even Sletteng; Andersen, Tom; Engseth, Erik; Kristiansen, Kåre Andre & Wiik-Nielsen, Jannicke [Vis alle 7 forfattere av denne artikkelen] (2024). Conspicuous parasite modifies appearance and energetics of a marine copepod. ICES Journal of Marine Science. ISSN 1054-3139. 81(10), s. 2052–2064. doi: 10.1093/icesjms/fsae150. Fulltekst i vitenarkiv Vis sammendrag

  Parasitism is an important driver of ecosystem processes. Copepods are fundamental trophic links in marine food webs and harbour many microeukaryotic parasites, but unreliable access to infected individuals limits quantitative studies of parasite infection costs. Calanus spp., (helgolandicus or finmarchicus), infected with the Yellow-Hyphal Parasite become pigmented and are found near the surface, suggesting predator-mediated dispersal. Conventional markers prevented phylogenetic inference but confirmed that the parasite is not Ichthyophonus hoferi, as previously thought. We identified the pigments, quantified the pigment content and respiration rate, and derived stable isotope signatures of infected and uninfected Calanus spp. to examine costs of infection. We found that the pigments were astaxanthin and β-carotene, associated with the host and parasite, respectively. Parasitized hosts had increased astaxanthin content, reduced respiration rate, and lower lipid content. Ultrastructure imaging revealed parasitic cells associated with lipids in the haemocoel. The changes to host phenotype have detrimental impacts on energetics and the ecology of Calanus. We discuss the role of pigments in parasite-host interactions and suggest that the parasite produces β-carotene pigment for its physiological benefits. The trade-off between physiological benefits of pigments and conspicuousness for parasites is relevant in zooplankton-host systems, as zooplankton rely heavily on transparency for survival.

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• Garvang, Even Sletteng; Skogvoll, Vidar & Andersen, Gard Lilledal (2026). Under Kappa #86 - The Thing vs. Mystique, med Gard Lilledal Andersen - Steinhard hud og skuespill. doi: https:/www.underkappa.no/2188463/episodes/19742123-86-the-thing-vs-mystique-med-gard-lilledal-andersen-steinhard-hud-og-skuespill. Fulltekst i vitenarkiv
• Heuschele, Jan David & Garvang, Even Sletteng (2026). Hopp Hopp Hoppekreps - A Norwegian children's song about copepods. doi: 10.5281/ZENODO.22082053. Fulltekst i vitenarkiv Vis sammendrag

  "Hopp hopp hoppekreps" is a children’s song about copepods. It aims to bring awareness to one of the most important animal groups in aquatic environments - copepods. The accompanying leaflet has two pages, one that takes the role of a children’s book and one showing the complete song text. In the children’s book, we take some of the verses and illustrate the biological context. The 2 pages are meant to be printed double-sided on sheet of A4 paper, then folded three times, and after a small cut on the indicated line, one can fold it into a mini booklet (or “zine"). The booklet is meant for distribution on science fairs or to be printed out at home as a small children's book.

• Nyeggen, Margot Ulfsdatter; Christiansen, Svenja; Garvang, Even Sletteng; Andersen, Tom; Heuschele, Jan David & Titelman, Josefin (2025). Zooplankton community dynamics in Oslofjorden. Fulltekst i vitenarkiv
• Garvang, Even Sletteng; Heuschele, Jan David; Konestabo, Heidi Sjursen; Andersen, Tom; Riemann, Lasse & Titelman, Josefin (2025). Replication Data for: Parasite infection shapes the pathobiome and behavior of marine zooplankton. doi: https:/scholar.google.com/citations?view_op=view_citation&hl=sv&user=ycTVkNkAAAAJ&sortby=pubdate&citation_for_view=ycTVkNkAAAAJ%3A3s1wT3WcHBgC. Fulltekst i vitenarkiv Vis sammendrag

  We collected Calanus helgolandicus from the Oslofjord, both healthy individuals and infected with a conspicuous" yellow-hyphal" parasite that changes the host behavior. We incubated them for 7 days and measured behavior and survival. At the start and end of the incubation we sampled animals for 16S rRNA microbial community analysis. Infected Calanus had higher mortality, more risky behavior and altered microbiomes compared to the uninfected.

• Skogvoll, Vidar; Garvang, Even Sletteng; Wahl, Andreas Solberg; Dahlen, Pia Ve; Andersen, Gard Lilledal & Røyne, Anja (2025). Under Kappa #55 - Fantastiske 4: Mysteriet i Oslo. doi: https:/www.youtube.com/watch?app=desktop&v=phUVkoJXPJM. Fulltekst i vitenarkiv
• Garvang, Even Sletteng (2025). Det gule mysteriet - og andre parasitter i hoppekreps. doi: https:/www.youtube.com/watch?v=2LSG9akmNbY. Fulltekst i vitenarkiv Vis sammendrag

  Hoppekreps dominerer i verdens største økosystem: de frie vannmassene i havet. De er verdensmestere i å ikke bli spist i et miljø der alle vil spise dem, og har utviklet seg for å finne både mat og en partner i et hav der det er tonnevis av vann mellom dem og målene deres. Men det lurer andre farer enn predatorer i planktonet, og kanskje er hoppekrepsen offer for sin egen suksess?

• Garvang, Even Sletteng; Heuschele, Jan David; Konestabo, Heidi Sjursen; Andersen, Tom; Riemann, Lasse & Titelman, Josefin (2025). Parasite infection shapes the pathobiome and behavior of copepods. Fulltekst i vitenarkiv
• Garvang, Even Sletteng (2024). Zooplankton pandemics - Parasite outbreaks in copepod populations. Fulltekst i vitenarkiv
• Jemterud, Torkild; Bjorå, Charlotte Sletten; Sletsjøe, Arne Bernhard & Garvang, Even Sletteng (2024). Abels tårn. [Radio]. NRK P2. Fulltekst i vitenarkiv
• Garvang, Even Sletteng (2024). Zooplankton pandemics – Conditions for parasite outbreaks in copepod populations. Fulltekst i vitenarkiv
• Skogvoll, Vidar; Garvang, Even Sletteng & Reinertsen, Marianne (2024). Under kappa - #21 - Wonder woman - Lassojuss, løgndetektorer og pistolreker med marianne reinsertsen. [Radio]. Podcast. Fulltekst i vitenarkiv
• Andersen, Ida Yasin; Bendiksen, Kristian; Slangsvold, Einar Lie; Skogvoll, Vidar & Garvang, Even Sletteng (2024). Studio 2 - Påskeharen som superhelt. [Radio]. P2. Fulltekst i vitenarkiv
• Skogvoll, Vidar; Garvang, Even Sletteng; Brugård, Anne & Ottem, John Christian (2024). Under Kappa - #29 - The Riddler - Gode nøtter, smarte dyr og spillteori med Anne Brugård og John Christian Ottem. [Radio]. Podcast. Fulltekst i vitenarkiv
• Skogvoll, Vidar & Garvang, Even Sletteng (2024). Under Kappa - #28 - Professor X - Live! Mutantgener og fysikken bak hjernekontroll. Fulltekst i vitenarkiv
• Skogvoll, Vidar; Garvang, Even Sletteng & Hval, Halvor Høen (2024). Under kappa - #25 - Green lantern - Batterier, farger, følelser og plancks konstant med halvor høen hval. [Radio]. Podcast. Fulltekst i vitenarkiv
• Jemterud, Torkild; Skogvoll, Vidar & Garvang, Even Sletteng (2024). Abels tårn - Hva slags superkrefter har påskeharen? [Radio]. P2. Fulltekst i vitenarkiv
• Garvang, Even Sletteng & Skogvoll, Vidar (2023). Under Kappa - #5 - The Flash - Raske dyr og tidrommet. [Radio]. Podcast. Fulltekst i vitenarkiv
• Eliassen, Lasse Krøger; Garvang, Even Sletteng; Andersen, Tom; Engseth, Erik; Kristiansen, Kåre Andre & Wiik-Nielsen, Jannicke [Vis alle 7 forfattere av denne artikkelen] (2023). A parasite-copepod association and its effects on host pigmentation and lipids. Fulltekst i vitenarkiv
• Garvang, Even Sletteng & Skogvoll, Vidar (2023). Under Kappa - #6 - Catwoman - Katter, og hvorfor de alltid lander på beina. [Radio]. Podcast. Fulltekst i vitenarkiv
• Garvang, Even Sletteng & Skogvoll, Vidar (2023). Under Kappa - #4 - Supermann - Astrofysikk og romvesenbiologi. [Radio]. Podcast. Fulltekst i vitenarkiv
• Andersen, Ida Yasin; Bendiksen, Kristian; Slangsvold, Einar Lie; Skogvoll, Vidar & Garvang, Even Sletteng (2023). Studio 2 - Julenissen som superhelt. [Radio]. P2. Fulltekst i vitenarkiv
• Skogvoll, Vidar; Garvang, Even Sletteng & Bremnes, Inge (2023). Under kappa - #19 - Black bolt - Stemmeteknikk, lyd og bråkete dyr med Inge bremnes. [Radio]. Podcast. Fulltekst i vitenarkiv
• Skogvoll, Vidar; Garvang, Even Sletteng & Andersen, Guro Lilledal (2023). Under Kappa - #15 - The Thing - Stein, dyr med skall og superharde materialer med Guro Lilledal Andersen. [Radio]. Podcast. Fulltekst i vitenarkiv
• Skogvoll, Vidar; Garvang, Even Sletteng & Winnberg, Kirsti (2023). Under Kappa - #13 - Hell Cow - Kyr, blodsugende dyr og effektive fly med Kirsti Winnberg. [Radio]. Podcast. Fulltekst i vitenarkiv
• Skogvoll, Vidar; Garvang, Even Sletteng & Uggerud, Nora (2023). Under kappa - #11 - Scorpion - Syre, vannkanoner og skorpioner med Nora Uggerud. [Radio]. Podcast. Fulltekst i vitenarkiv
• Andersen, Ida Yasin; Bendiksen, Kristian; Slangsvold, Einar Lie; Skogvoll, Vidar & Garvang, Even Sletteng (2023). Studio 2 - Fysikk og biologi i superheltfilmen The Flash. [Radio]. P2. Fulltekst i vitenarkiv
• Skogvoll, Vidar & Garvang, Even Sletteng (2023). REAL kino: Thor! Fulltekst i vitenarkiv
• Garvang, Even Sletteng; Eliassen, Lasse Krøger; Titelman, Josefin & Andersen, Tom (2022). Modeling the parasites of copepods. Fulltekst i vitenarkiv
• Garvang, Even Sletteng (2022). My master’s experience: parasites, tiny animals and nothing going as planned. Fulltekst i vitenarkiv
• Eliassen, Lasse Krøger; Garvang, Even Sletteng; Andersen, Tom; Engseth, Erik; Kristiansen, Kåre Andre & Wiik-Nielsen, Jannicke [Vis alle 7 forfattere av denne artikkelen] (2022). The yellow-hyphal parasite in Calanus finmarchicus. Fulltekst i vitenarkiv
• Titelman, Josefin; Eliassen, Lasse Krøger; Garvang, Even Sletteng & Andersen, Tom (2021). Parasite disease in coastal zooplankton. Fulltekst i vitenarkiv
• Titelman, Josefin; Eliassen, Lasse Krøger; Garvang, Even Sletteng & Andersen, Tom (2021). Parasite disease in coastal zooplankton. Fulltekst i vitenarkiv
• Garvang, Even Sletteng (2026). The impact of microbial parasites on copepods: quantitative answers to a century-old mystery. Universitetet i Oslo. Fulltekst i vitenarkiv Vis sammendrag

  Pelagic copepods are possibly the most abundant group of animals on the planet, and are central in marine food webs. Copepods host numerous parasites with detrimental effects. However, these parasites have mostly been ignored since their discovery more than 100 years ago. In my thesis I have combined field sampling, experiments and modeling to investigate the occurrence of copepod parasites and their effects on individuals, populations and communities. An initial modeling study showed that the population impact of copepod parasites may be large, and pinpointed important parasite traits for infection dynamics. Combining estimates based on the literature with new experiments we found that the release of parasite spores scales with host size, and that larger copepods experience higher infection pressure. We quantified mortality increase and behavioral change induced by the elusive Yellow-Hyphal Parasite, and found that infection was associated with an altered bacterial microbiome. Using a combination of molecular methods and biomass data, we found widespread parasitism year-round in the Oslofjord. Parasite prevalence reached a seasonal peak of 100%, and was often over 50%. This thesis shows that the parasites of copepods are widespread and prevalent, and may play a larger role in plankton ecology than previously believed.

• Fransson, Agneta; Bluhm, Bodil; Arumi, Marti A.; Assmann, Karen; Gravelle, Amalie M. & Bratrein, Marius [Vis alle 34 forfattere av denne artikkelen] (2022). The Nansen Legacy Report Series. No. 30 - Joint Cruise 2-2 2021: Cruise report. UiT Norges arktiske universitet. Fulltekst i vitenarkiv

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