04 April: The SLRC Annual Report 2017 has been published

31 October: Trafikklyssystemet som underlag for¬†kapasitetsjustering i √łrret- og lakseproduksjon.

N√¶rings -og fiskeridepartementet (NFD) har satt ned en styringsgruppe som skal gi faglige r√•d om d√łdelighet hos villaks som f√łlge av lakselus. R√•dene fra styringsgruppen er basert p√• rapporter som er utarbeidet av eksperter p√• lakselus fra ulike norske forskningsmilj√ł. R√•dene vil danne grunnlaget for NFDs utvikling og bestemmelser for trafikklyssystemet som verkt√ły for √• regulere kapasitetsendringer i laks- og √łrretproduksjon i Norge.

Gruppen av eksperter som har laget underlagsrapportene er ledet av professor Frank Nilsen ved UiB Рhan er også senterleder ved SLRC. Link til rapporten


25 October: New SLRC Publication: RNAi-mediated treatment of two vertically transmitted rhabdovirus infecting the salmon louse (Lepeophtheirus salmonis)

Recently it was discovered that the salmon louse carry a variety of different viruses ( A new study conducted at the Sea Lice Research Center, SLRC, shows that two of these viruses are present in almost all lice sampled along the Norwegian coast. So far it has been difficult to study the biology of these viruses since there are no infection models available and no suitable cell lines for propagation. In order to establish a tool for further studies, researchers at SLRC have developed a RNA interference (RNAi) based treatment that cure infected salmon lice. In this way virus free and virus positive salmon lice strains can be established from a common virus infested origin. This is an important principle that provides the means to study the specific effects of the virus and its infection routes. Previous studies have shown that the viruses are transferred vertically, from mother to offspring. However, the present study shows that one of the viruses is also transmitted horizontally from infected adult males to females living on the same fish, and to a lesser extent, or possibly not at all, from adult females to males. Several experiments based on this method are at present conducted to increase our knowledge of these viruses and also how they potentially interact with the salmon immune system.
The full article is available at



New PhD in SLRC

helleApril 4th, Helle Jodaa Holm successfully defended her PhD named ‚ÄúImmunological response profiles to salmon lice infections in Atlantic salmon. Modulation by nutrition and selective breeding‚ÄĚ, which is an important scientific step for SLRC.

The integrated lice management approach, involving the use and rotation of multiple methods for salmon lice management and control is important to hinder the development of resistance against anti-lice chemicals. Functional feeds and selective breeding are considered two promising alternative approaches for management of salmon lice infections. Understanding the molecular basis of protection against salmon lice is expected to help in their successful application in Atlantic salmon aquaculture. Helle’s thesis have elucidated immunological pathways, including interferon and T helper cell related molecular pathways, involved in susceptibility and resistance to salmon lice in a selective breeding study of over 5000 Atlantic salmon individuals in collaboration with AquaGen. Similar immune components were also associated with protection against salmon lice in studies on the effects of feeding Atlantic salmon glucosinolate enriched functional feeds developed with Cargill Innovation (Ewos Innovation). Both approaches resulted in significantly reduced lice numbers. Helle’s thesis gave rise to four published papers in international peer-reviewed scientific journals.

The defense was held in front of the audience at the University of Life Sciences campus Adamstuen and the opponents Professor Ian Bricknell from the University of Maine and Professor James Bron from the University of Stirling, both very knowledgeable in the salmon lice field. The topic for the trial lecture was ‚ÄúThe impact of climate change for aquaculture‚ÄĚ. Later, a great discussion developed between the opponents and Helle on topics related to her thesis. Opponents described Helles thesis as ‚Äúextremely well written‚ÄĚ, ‚Äúterrific work‚ÄĚ with ‚Äúcapacity to produce real-world impact‚ÄĚ. It was pointed out that Helle‚Äôs collaboration with industrial partners Cargill Innovation (Ewos Innovation) and AquaGen to develop alternative methods for salmon lice management and control was very successful. Furthermore, Helle‚Äôs focus on animal welfare throughout her thesis was acknowledged, in addition to excellent microscopy skills, thorough use of references and understanding of literature, and eye for details.

The vegetarian dinner was served later that day to celebrate the event with Helle’s family and friends, in addition to colleagues and opponents.

All in all, a great ending of one important step in Helle’s scientific career and a continuation that will hopefully be as exciting or even better. Helle will now continue as a researcher in WP2, focusing on developing functional feeds against sea lice.

30 March: The SLRC Annual Report 2016 has been published


20 March: SLRC presentation at “Open Day at UiB

On Wednesday March 8 students from upper secondary school were invited to visit the University of Bergen at Open day. The students attended lectures about current research and participated in different laboratory demonstrations. In one of the demonstrations, researcher Christiane Eichner and professor Rune Male from the Sea Lice Research Center and Department of Molecular Biology demonstrated sea lice. The students was allowed to see adult sea lice, hatching of egg strings and larva of different stages.
Students looking at Sea Lice


02 February: New publication on Heme Peroxidases

slrcsiden_aina1702Heme peroxidases are the most abundant type of peroxidase, found in all kingdoms of life from bacteria, fungi and plants to invertebrate and vertebrate animals. Heme peroxidases reduce hydrogen peroxide to water by oxidation of a variety of substrates. The heme group within its active site catalyze this oxidation. Heme peroxidases are involved in numerous processes like the innate immune response, hormone and prostaglandin synthesis and crosslinking of proteins within extracellular matrixes (ECM) as well as cuticle and chorion molecules of arthropods and nematodes. In the salmon louse, Lepeophtheirus salmonis, heme peroxidases have been analyzed in regards to their role in drug resistance and host immune modulation, however, very little is known about their involvement in salmon louse ECMs and cuticle structures. The aim of the current study was therefore to identify a structural salmon louse heme peroxidase and analyze its involvement during development. A heme peroxidase named LsHPX1 was characterized exhibiting a dynamic expression during ontogenesis (Fig A). Transcripts were localized to muscle cells (Fig C), in nerve tissue (Fig B), epithelium, the tissue below the epithelium (subepithelial tissue, Fig D), exocrine glands and in the testis. Knock-down of LsHPX1 in nauplius larvae decreased the swimming activity of emerging copepodids, as the legs of the LsHPX1 knock-down copepodids were positioned in a 45 to 90 degree angle away from the body (Fig F), as opposed to controls where legs were normally aligned against the body (Fig E). Histological analysis of knock-down animals revealed changes in muscle (Fig I), subepithelial (Fig J), and exocrine gland tissue. Considering these results, the potential role of LsHPX1 in crosslinking molecules of salmon louse ECMs was suggested, with a particular importance for crosslinking the junction between nerve and muscle tissue during development. Link to publication


06 October: Awards to SLRC at the Sea Lice 2016 Conference

Poster Prize
Hulda Hardardottir, PhD student at the Sea Lice Research Centre received a 2nd prize in the poster competition the Sea Lice 2016 conference in Westport, Ireland, September 2014. In her poster, “Molting cycle, morphological changes in cuticle and transcriptional level of key chitin biosynthesis genes” Hulda described her study of molting in salmon louse and associated changes in gene transcription.


 The Kabata Award to Tor Einar Horsberg

Tor Einar Kabata Award

Professor Zbigniew (Bob) Kabata (1924 ‚Äď 2014) was a highly respected Polish and Canadian fish parasitologist. He is internationally recognized as the foremost expert on the parasitic Copepoda as well as pioneering studies on parasites as biological tags. He described more than 20 new genera and over 100 new species; refereed numerous scientific publications in multiple languages and published a number of books dealing with various aspects of the parasitic Copepoda.

In 2014, the international Sea lice conference introduced ‚ÄúKabata award‚ÄĚ as an honor to a scientist, who is known for his achievements and contributions to the Sea Lice world. In 2016, at the 11th international Sea lice conference in Ireland, this award was presented to Prof. Tor Einar Horsberg from Norwegian University of Life Sciences, School of Veterinary Sciences. A scientific committee of his peers selected him as a winner of this prestigious award. Prof. Horsberg is one of the work package leaders in Sea lice Research Centre since 2011. He is a world-renowned figure for his research on sea lice and published many articles both nationally and internationally. His research on sea lice has also resulted in three patents in collaboration with PatoGen Analyse AS and provided new ways and better tools to combat sea lice in an effective manner. He is an inspiration to his fellow workers and students.




30 September: New SLRC publication on Exocrine glands  of Lepeophtheirus salmonis

Exocrine glands are glands that secrete substances through a duct, often onto the external surface of the animal. Exocrine glands of blood-feeding parasites are believed to be important in pre-digestion of food and in the host-parasitic interaction by secretion of substances that modulate the immune response of the host and limit clotting of the blood. It is important to know more about these glands in salmon lice, as they may offer vaccine candidates. In this paper we have identified four types of exocrine glands, localized them within the lice and followed their ducts to identify where the different gland types secretes their glandular products. We have also looked at the developmental appearance of the gland and identified some genes expressed by two of the gland types.

4 glands_namesThe first two glands to appear during salmon lice development are called tegumental (teg) type 1 and 2 glands (Figure). They are found from the nauplius I stage, and have secretory ducts extending both dorsal and ventral. They are thus suggested to be important in secreting anti-fouling agents decreasing the water drag to the lice (teg 1), or lubricating exposed areas (teg 2). The labial glands have secretory ducts extending into the salmon lice oral cavity, and are likely to deposit the secretion directly onto the fish. The labial gland was first identified at the planktonic copepodid stage, making the copepodid ready to start feeding once it settle on its host. The last gland type to appear during development was named teg 3 glands, and was not identified before the lice enter the preadult stage. At this point in development the lice reaches a virulent phase, capable of inflicting substantial damage to the host. Moreover, teg 3 glands have secretory ducts ending at the host-parasitic contact area. Hence, the teg 3 glands secretions may be an important virulence factor for the lice. Link to publication


14 September: The Minister of Fisheries, Per Sandberg, on visit to SLRC

Today the Minister of Fisheries, Per Sandberg, visited SLRC. He was shown the LiceLab facility where most of the experiments in the centre are conducted. The Minister showed great interest in the facilities for single fish tanks which increases the capacity for experiments connected to development of new medicines and vaccines. He was also shown some of the lice strains that are maintained both sensitive strains and lice resistant to various medicines.

Ministerbes√łkThe minister was especially interested in the cooperation between industry and academia and asked how functional our centre had been. Further, the Director of SLRC presented some of the activities in the centre and underlined the importance of knowledge of sea lice biology as an important basis for solving/handling the sea lice problem. One example of the SLRC work with scientific approach is using genetic trackable sea lice for studying dispersion of sea lice between farms. The results can be important information for future decisions on where new farms should be placed.

In LiceLab, the minister could see both copepodids and adult sea lice and Director Nilsen explained how many offspring each lice can produce. Other sea lice were also shown and Nilsen explained why salmon lice only will attach to Atlantic salmon and trout. See more of the presentation by Frank Nilsen


24 May: Liv Sandlund has today defended her PhD thesis
at the University of Bergen. Her thesis ‚ÄúFunctional investigations of the Ecdysone Receptor and production of ecdysone in the salmon louse (Lepeophtheirus salmonis)‚ÄĚ is of great value for the work in SLRC. IMG_6070

Steroid hormones in development and reproduction of the salmon louse
The salmon louse is a small crustacean with an exoskeleton that lives as parasite on salmon in saltwater. Salmon lice feed on fish blood, mucus and skin and when there are many lice this can cause wounding of the fish. Salmon lice infections are currently the most challenging disease in Norwegian aquaculture. It is therefore important to get the basic knowledge about the biology of salmon lice to combat salmon lice in the future.

In crustaceans, and all other animals that moult, the development and the ability to multiply is controlled by ecdysteroid hormones. These hormones bind to a receptor called the ecdysteroid receptor (ECR) that is located in the cell nucleus. Together they bind to the genetic material (DNA) where they govern which genes will be expressed and in this way decide what tasks the cell should perform. Which hormones and how they work has until now been unknown in lice. The aim of this thesis has been to increase knowledge about how this hormone system affects important biological processes in the salmon louse. Through her doctoral thesis Sandlund has characterized the ecdysone receptor (ECR) and examined what happens in lice if you “turn off” production of ECR. The studies show that impaired ECR function leads to serious problems in the development of various organs and increased mortality among lice. In addition, it was observed that females with impaired ECR function did not produce eggs. In her dissertation, Sandlund has furthermore identified and studied enzymes essential for production of ecdysteroid hormones. The results of these studies pinpoints some important deviations from the fruit fly (Drosophila) which is regarded as a model for studies of this hormone system. Such deviations provides important information about the evolution of a conserved system. In addition, a possible regulator of these enzymes and ECR was identified. The work has provided important new knowledge about the salmon louse biology.


12 May: The SLRC spring workshopIMG_1214
was arranged at Sotra outside Bergen. In all, 35 SLRC People were coming together to give talks about new research and discuss different aspects of salmon louse biology. Dispite the differences in approaches, a common aim of all was to come  nearer a solution to combat the sea lice problem Norwegian ans Chilean aquaculture is facing due to resistance to existing anti lice drugs. Bright sunshine and panorama view to the fjords also contributed to the good athmosphere of this meeting ans made a good basis for networking and development of new ideas for collaborating projects.


14 December:  Benedicte Fossum er ny styreleder i Sea Lice Research Centre (SLRC).
Fossum har bred styreerfaring og solid kompetanse innen veterin√¶rmedisin og kommersiell anvendelse av forskning. Som ny styreleder i SLRC f√•r hun f√•r en viktig rolle i √• lede senteret slik at bidraget til oppdrettsn√¶ringen blir st√łrst mulig.

Benedicte Fossum er utdannet veterin√¶r fra Norges Veterin√¶rh√łgskole og har lang arbeidserfaring fra b√•de offentlige og private selskaper. Hennes brede styreerfaring, b√•de i oppdrettsselskaper og forskningsbaserte selskaper, er verdifull for SLRCs strategiske satsning p√• kommersialisering og fortsatt lederskap innen lakselusforskning.

‚Äď SLRC er verdensledende innen forskning p√• lakselus, og m√•let er √• finne l√łsninger p√• utfordringene n√¶ringen st√•r overfor. I samarbeid med partnerne i senteret er det allerede utviklet produkter og metoder for bedre kontroll med lusesituasjonen. Sammen med resten av styret ser jeg frem til √• lede senteret i riktig retning for √• finne effektive og langsiktige l√łsninger for √• f√• kontroll p√• problemene med lakselus, sier Fossum.

En ekspertgruppe utnevnt av Forskningsr√•det gav nylig SLRC toppkarakter for sv√¶rt solid og variert kompetanse, entusiastiske medarbeidere og h√ły produksjon. Senteret g√•r n√• inn i en fase med fokus p√• de anvendte aspektene ved forskningen, og styret har derfor engasjert Benedicte Fossum som ny styreleder.

Professor Frank Nilsen, direkt√łr ved SLRC, ser frem til neste fase for senteret. ‚Äď SLRC har siden oppstarten for 4 √•r siden opparbeidet en unik kunnskapsbase om biologien til lakselusa og etablert et forskningssenter uten sidestykke p√• verdensbasis; vi er n√• godt rigget til √• finne l√łsninger som n√¶ringen kan ta i bruk. Jeg tror Fossum vil tilf√łre viktig erfaring omkring hvordan senteret skal bruke kompetansen og infrastrukturen p√• best mulig m√•te for √• bidra i kampen mot lusa, sier Nilsen.

Vidar Aspehaug, styremedlem i SLRC, har ledet arbeidet frem til valg av ny styreleder for senteret.

‚Äď Partnerne i SLRC har v√¶rt gjennom en grundig prosess for √• finne riktig styreleder for senterets neste fase. Vi har vurdert flere kandidater, og er sv√¶rt forn√łyd med engasjementet Fossum viser for √• lede senteret. Jeg vil samtidig, p√• vegne av partnerne og styret i SLRC, benytte anledningen til √• takke avtroppende styreleder Audun Wiborg for viktige bidrag i senterets f√łrste fire√•rsperiode, sier han.


01 December: New Publication; ¬†Eichner C, √ėverg√•rd AC, Nilsen F, Dalvin S.
Molecular characterization and knock-down of salmon louse (Lepeophtheirus salmonis) prostaglandin E synthase. Exp Parasitology, Volume 159, 2015 Dec. Pages 79-93



26  October: Lecture by Professor Simon Jones

Simon Jones¬†Professor Simon Jones, University of Victoria, Canada will come¬†¬† to Bergen and give a lecture on: ‚ÄúSea Lice ecology from a pacific¬† perspective: ecology and host interaction‚ÄĚ

Dr. Jones is the lead scientist in the finfish parasitology program at DFO’s Pacific Biological Station in British Columbia, Canada. His main field of work is within Aquaculture, Aquatic Animal Health and Biothechnology/Genomics. This week Dr. Jones will be a guest lecturer at the PhD Course in Sea Lice Biology, arranged by SLRC and Molecular and Computational Biology Research School (MCB) at UiB.

Date: Tuesday 27 October at 12:15, Lille Auditorium, H√łyteknologisenteret


01 October: Midterm Evaluation: Sea Lice Research Centre  received good marks in the report from the midterm evaluation of the centre. The Executive Board of the Research Council of Norway has this week decided to extend the funding to SLRC for the additional three year period. Frank Nilsen, Director at SLRC, is pleased with the feedback the centre got on the excellent research going on in the centre.

SLRC was evaluated in March 2015 by an international evaluation panel headed by Alison McKay at University of Leeds, in addition to Dr Mattias Lundberg, Swedish Foundation of Strategic Research, Dr. Alan Bowman, University of Aberdeen and Dr David Jackson, The Marine Institute, Galway

Read more at NFR/SFI and UiB
Link to the SFI II Evaluation Report


21 July: New Scientific paper: Characterisation of iron regulatory protein 1A and 1B in the blood-feeding copepod Lepeophtheirus salmonis  Link to article


09 June: SLRC Seminar on Sea Lice arranged in Bergen. The SLRC seminar gathered 85 participants that could hear about the latest research on sea lice and future challenges both for the sea farming industry and the environment.


29 April: New Scientific paper: Sequence Analysis and Identification of New Isoform of EP4 Receptors in Different Atlantic Salmon Tissues (Salmo salar L.) and Its Role in PGE2 Induced Immunomodulation In Vitro

Prostaglandin E2 (PGE2) is an important lipid modulator for immune response. The effect is exerted through different receptors called EP and four different subtypes of these receptors (EP1-4) have been identified in mammals. PGE2 found on the salmon louse secretions is thought to mediate the immuno-dampening effect during infection in Atlantic salmon but concrete evidence is yet to be provided. Before this to happen, however, knowledge about PGE2 receptors and its role in modulating the immune responses in Atlantic salmon must be established. In this study we have identified new isoform of Atlantic salmon EP4 (named EP4b) and performed sequence analysis for both Atlantic salmon EP4 receptors and their counterparts from different fish and higher vertebrate species. We have also investigated the role of the new identified isoform in modulating the inflammatory responses in vitro. Our data indicate that the PGE2 function as modulator is conserved while more studies are required to understand the detailed mechanisms involved.
Link to publication:


20 March: The SLRC Annual Report 2014 has been published


24 February: New Sceintific paper: Characterization of a novel RXR receptor in the salmon louse (Lepeophtheirus salmonis, Copepoda) regulating growth and female reproduction

Copepods comprise a large and diverse group of aquatic arthropods which has received little attention in molecular studies. Sea lice like the salmon louse are known to cause significant economic loss in sea ranching of Atlantic salmon. In order to understand important biological processes like sexual maturation and reproduction in female salmon louse we have identified and characterized an RXR nuclear hormone receptor. Our sequence analysis of LsRXR revealed a unique insertion of 10 Asp residues which has significance for the secondary structure of the molecule. We show that LsRXR is closest related to USP from insects. Through our RACE experiment we identified five different LsRXR transcripts of different length where the main differences are domain composition (i.e. complete DBD, partial DBD or no DBD). Q-PCR analysis showed that the shortest LsRXR forms comprised about 50% of the transcripts in all the investigated developmental stages. To further gain information regarding the function of LsRXR we used RNAi to knock-down this gene in adult female lice. This resulted in severe effects on the reproductive output and close to zero viable offspring’s. Histological examinations in some of these female lice revealed destructions in the ovaries and oocytes pointing towards that LsRXR has effects both on gamete production and maturation. Microarray assessment revealed that knock down of LsRXR has large effects on a wide range of genes. The major yolk proteins were all strongly down-regulated together with genes involved in lipid metabolism and transport. In general, growth processes were up regulated in the present study.

Link to publication:


¬†05 February: New Scientific paper: Molecular characterization and functional analysis of LsChi2, a chitinase found in the salmon louse (Lepeophtheirus salmonis salmonis, Kr√łyer 1838)

 The salmon louse has a rigid exoskeleton that consists mostly of chitin. Therefore, in order to grow the salmon louse needs to molt. Molting is a process where the old exoskeleton sheds off and is replaced with a new and larger exoskeleton. Chitin is degraded by enzymes called chitinases. There are two pesticides targeting chitin available on the market today, called diflubenzuron and teflubenzuron. These chemicals inhibit the production of chitin and cause death to the parasite. However, the use of these pesticides has led to concern regarding the effect on other crustaceans.

More knowledge is necessary about the molting process in salmon lice, and the biological role of chitinases. In the salmon louse three chitinases were found. In this study these were characterized and the function of one of them was investigated by gene knock-down in nauplius larvae, followed by an infection trial with emerging copepodids. Knock-down caused deformed larvae and reduced infection success.
Link to publication:


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