Article
Evolutionary Biology
Karoline Hasti Rutle, Rasmus Skern-Mauritzen, Frank Nilsen, Alejandro Mateos-Rivera, Anne Grete Sorvik Eide, Eeva Jansson, Maria Quintela, Francois Besnier, Fernando Allyon, Helene Borretzen Fjortoft, Kevin Alan Glover
Summary: Resistance toward the antiparasitic pyrethroid deltamethrin has been reported in the Atlantic salmon louse, and it is linked to mitochondrial DNA. This study investigates the impact of widespread pyrethroid use on mtDNA variation in lice and the dispersion of resistant haplotypes across the North Atlantic.
EVOLUTIONARY APPLICATIONS
(2023)
Article
Genetics & Heredity
Jay Joshi, Anne-Marie Flores, Kris A. Christensen, Hollie Johnson, Ahmed Siah, Ben F. Koop
Summary: This study used long-read sequencing technology to update the genome assemblies of Atlantic and Pacific salmon lice, and identified unique genomic features of their sex chromosomes. Moreover, conserved orthologous protein sequences were found between the W- and Z-chromosomes.
G3-GENES GENOMES GENETICS
(2022)
Article
Fisheries
Cameron Thompson, Samantha Bui, Sussie Dalvin, Rasmus Skern-Mauritzen
Summary: This investigation focused on the fecundity of salmon louse and found that the total length of female lice is the primary determinant of clutch size. The study also revealed that female louse total length is partially influenced by the sampling temperature. Moreover, the investigation showed that incorporating female louse sexual maturity and clutch size parameter related to female lice's total length could improve the forecasts of salmon louse production.
AQUACULTURE ENVIRONMENT INTERACTIONS
(2023)
Article
Biochemistry & Molecular Biology
Claudia Tschesche, Michael Bekaert, Joseph L. Humble, James E. Bron, Armin Sturm
Summary: The pyrethroid deltamethrin and the macrocyclic lactone emamectin benzoate are used to treat farmed salmon infestations by parasitic salmon lice. Drug resistance in the lice is associated with overexpression of ace1b, a member of the functionally diverse carboxylesterases family. The study identified 21 CaEs genes/pseudogenes in L. salmonis, with overexpression of ace1b observed in multi-resistant lice compared to susceptible ones.
COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY C-TOXICOLOGY & PHARMACOLOGY
(2021)
Article
Fisheries
Tina Oldham
Summary: Several preventive tools and strategies have been developed to combat salmon lice in marine cages, but their efficacy varies depending on environmental conditions. A meta-analysis showed that integrated prevention strategies combining behavior modification with skirt barriers provided the most consistent protection, while snorkel barriers offered the highest potential protection. However, snorkel barriers were more sensitive to environmental variation and had negative effects on growth and gill health. Understanding the interrelationships between preventive tools and environmental conditions is crucial for optimizing their practical applicability.
Article
Fisheries
Trond Nordtug, Bjarne Kvaestad, Andreas Hagemann
Summary: This study provides experimental data on the responses of the infectious copepodid stage of salmon lice to different light qualities and intensities from underwater light sources. The findings suggest that underwater light sources commonly used in salmon farming may attract salmon lice copepodids and increase infection pressure under certain conditions. Light traps may also be effective in catching planktonic salmon lice. Further research is needed to test the actual effects of underwater light sources on the local distribution of salmon lice.
Article
Multidisciplinary Sciences
Aina-Cathrine Overgard, Helena M. D. Midtbo, Lars A. Hamre, Michael Dondrup, Gro E. K. Bjerga, Oivind Larsen, Jiwan Kumar Chettri, Kurt Buchmann, Frank Nilsen, Sindre Grotmol
Summary: This study reveals the presence of charged glandular proteins in the salmon louse that have immune modulation and anti-coagulant properties. These proteins play important roles in regulating the parasite's life cycle and feeding behavior in the host.
SCIENTIFIC REPORTS
(2022)
Editorial Material
Fisheries
Ingrid A. Johnsen, Alison Harvey, Pal Naeverlid Saevik, Anne D. Sandvik, Ola Ugedal, Bjorn Adlandsvik, Vidar Wennevik, Kevin A. Glover, Orjan Karlsen
Summary: A model system was developed to estimate salmon lice-induced mortality, calibrated against empirical observations. Critics claim the model overestimates mortality, but their analysis may have shortcomings. Discrepancy between modelled and observed data does not necessarily indicate flaws, but can provide valuable supplementary information.
ICES JOURNAL OF MARINE SCIENCE
(2021)
Article
Multidisciplinary Sciences
Andreas Borchel, Anna Zofia Komisarczuk, Frank Nilsen
Summary: Salmon lice, ectoparasites on salmonids, have a significant impact on the aquaculture industry. This study successfully developed a sex determination assay for salmon lice, allowing for early identification of the developmental speed and sex-specific SNPs. However, only a few genes showed differential expression between the sexes.
Article
Multidisciplinary Sciences
Grace A. Wyngaard, Rasmus Skern-Mauritzen, Ketil Malde, Rachel Prendergast, Stefano Peruzzi
Summary: This study presents the first estimates of genome size for the ectoparasite Lepeophtheirus salmonis, indicating that the genome size of this species can vary. This variability may be explained by the proportion of repetitive DNA in the genome.
SCIENTIFIC REPORTS
(2022)
Article
Fisheries
Melanie Andrews, Tor Einar Horsberg
Summary: This study investigated the effects of thermal treatment on the copepodid and pre-adult II stages of seven populations of L. salmonis. The results showed that while all stages of the parasite had an immediate reaction to thermal treatment, the majority of them recovered over time. Variations in baseline sensitivity were observed between populations, emphasizing the importance of routine in vitro bioassays to determine treatment efficacy.
Article
Veterinary Sciences
Meadhbh Moriarty, Stephen C. Ives, Joanne M. Murphy, Alexander G. Murray
Summary: In order to protect wild salmon in areas where salmon aquaculture is practiced, it is important to understand the impact of the salmon louse on these wild salmon. A modelling structure was implemented in Scotland to assess the interaction between wild salmon and salmon lice from farms. The model considered the production and distribution of lice, infection rates on hosts, and the development of lice. The results showed that the impact of salmon lice depended on the size of the host, with smaller smolts being more susceptible.
PREVENTIVE VETERINARY MEDICINE
(2023)
Article
Biology
Hulda Maria Hardardottir, Rune Male, Frank Nilsen, Sussie Dalvin
Summary: Chitin synthase is a crucial enzyme involved in the survival and reproduction of aquatic organisms, with different expressions and functions in different tissues. Through RNA interference experiments, it was found that the chitin synthases of L. salmonis have significant impacts on the external cuticle and internal organs of lice at different developmental stages.
Article
Parasitology
Sussie Dalvin, Christiane Eichner, Michael Dondrup, Aina-Cathrine Overgard
Summary: The study revealed that knockdown of three potential PGES genes in salmon lice did not result in significant changes in phenotype, and did not affect the parasite's ability to infect or modulate the immune response of the host fish.
PARASITES & VECTORS
(2021)
Article
Parasitology
Andreas Borchel, Erna Irene Heggland, Frank Nilsen
Summary: Freshwater treatment has a detrimental effect on the egg strings of salmon lice, causing a collapse of their ordered structure and preventing the hatching of live animals. Shorter treatments and treatments with brackish water show milder effects. The egg strings have a protective effect against low salinities, while embryos react on a molecular level and delay hatching when treated with brackish water.
PARASITOLOGY RESEARCH
(2023)