Researchers at the University of Stirling have developed a precise method to collect and study secretory and excretory products from salmon lice, overcoming limitations that previously hid natural variations between individual parasites, according to a study published in Veterinary Parasitology.
Precision Sampling Transforms Salmon Louse Research
Led by PhD researcher Alexander Dindial alongside Professor James Bron and Dr Sean Monaghan at the University’s Institute of Aquaculture, in collaboration with Moredun Research Institute’s Kevin McLean, the team extracted secretions by placing a small drop of solution over individual salmon lice mouths. According to Mr Dindial, this technique allowed parasites to release proteins naturally into the droplet. The samples were subsequently examined using liquid chromatography tandem mass spectrometry, a state-of-the-art technique that separates sample components and breaks them into fragments to reveal exact protein compositions. This targeted approach yields high-quality secretory proteins from a single louse per test while significantly reducing potential faecal contamination, according to the findings.
Identifying Secretory Proteins for Vaccine Development
The analysis identified 148 total secretory proteins, with 64 detected across every tested condition, some of which could represent potential targets for future vaccine development according to the research team. Secretory protein profiles of individual lice showed wide variations in protein number and diversity. Mr Dindial stated that this pattern remains consistent with other ectoparasites like ticks and mosquitoes. Previous extraction methods relied on pooling large numbers of individuals together, which obscured the natural differences between individual lice that are vital for designing targeted treatments.
Economic Stakes for Atlantic Salmon Aquaculture
Salmon lice feed on the skin, mucus, and blood of fish, causing open wounds that lead to secondary infections, lower market values, and mortality. Treatments to tackle sea lice infestations in Atlantic salmon aquaculture cost the industry more than $1 billion a year, while certain existing controls can be expensive, unreliable, environmentally damaging, and detrimental to animal welfare. Mr Dindial explained that salmon lice cause hundreds of millions of pounds of damage annually to the global sector through lost production and control measures, making the understanding of these secretions an important step toward developing safe, effective control strategies.
Did you know? Previous extraction methods pooled large numbers of salmon lice together, which masked natural individual variations. The new University of Stirling assay allows researchers to collect high-yield secretory protein samples from just a single louse per test.
Broader Implications for Parasite Control
This study builds on a first-of-its-kind study led by Mr Dindial and published last year, which uncovered major differences in the secretions used by the parasite at different life cycle stages. According to the researchers, the novel protocol could also be used to investigate how drug or therapeutic treatments alter louse secretory activity. Funding for the current work came from EastBio as part of the lead researcher’s PhD studentship, with additional contributions from the Moredun Research Institute. Related collaborative research was conducted through the project “Towards lice-resistant salmon: functional genetics and genome editing to enhance disease resistance in aquaculture,” funded by the UK Biotechnology and Biological Sciences Research Council (BBSRC), Sustainable Aquaculture Innovation Centre, and Benchmark Genetics Limited.
Frequently Asked Questions
What are secretory and excretory products (SEPs) in salmon lice?
SEPs are substances released from the glands of salmon lice that make it easier for them to feed on fish and evade the host’s immune system, according to the University of Stirling researchers.
How does the new collection method work?
Researchers place a small drop of solution over the mouth of an individual salmon louse, allowing it to release proteins directly into the liquid. Liquid chromatography tandem mass spectrometry is then used to analyse the exact protein composition.
Why is studying individual salmon lice important?
Individual lice exhibit wide variations in protein diversity. Studying single specimens rather than pooled groups reveals vital biological insights that could help develop targeted treatments and vaccines, according to the study authors.
How much do sea lice infestations cost the aquaculture industry?
Treatments and damages related to sea lice infestations in Atlantic salmon aquaculture cost the industry more than $1 billion annually.
Stay Updated on Aquaculture Research
Explore more articles on our website or share your thoughts on parasite control strategies in the comments below.
Keep reading