New scientific findings emphasize the importance of the early immune response in natural sea lice resistance in Pacific salmon. Researchers have discovered that certain Pacific salmon species exhibit a rapid and robust response when sea lice attach, causing the parasites to fall off. Lene Sveen from Nofima, the Norwegian Institute of Food, Fisheries, and Aquaculture Research, led a recent study that focused on the interaction between sea lice and salmon, particularly examining the site of louse attachment on the skin.

The study concentrated on coho salmon, known for their natural resilience against sea lice. Instead of analyzing the entire immune system, the researchers honed in on the initial attachment site of the louse. This approach proved successful as it revealed that the battle against sea lice begins at this point. A quick response from the salmon can prevent the louse from establishing itself, according to project leader Nick Robinson at Nofima.

Findings from the study showed that coho salmon trigger a potent inflammatory response within two days of louse attachment. Immune cells gather at the attachment site, hindering the parasite's ability to take hold. In contrast, Atlantic salmon exhibit a weaker response. Not only coho salmon but also other Pacific species like chum and pink salmon display impressive defenses against sea lice.

The research highlighted that these species have a high density of mucous cells in their skin, making it challenging for sea lice to attach successfully. The study, conducted as part of the CrispResist project, involved an international team of experts from science and industry. Over four years, the team has made significant progress in understanding why some Pacific salmon species are more resistant to sea lice than Atlantic salmon.

According to Sveen, the latest findings have generated new ideas for further research that could lead to solutions for enhancing the resistance of Atlantic salmon to sea lice. The CrispResist project partners include various institutions and organizations like Nofima, University of Edinburgh, Mowi, and Salmar, among others, and is funded by FHF - The Norwegian Seafood Research Fund.

Source: Aquafeed.com