Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The sea louse, a common parasite of wild fish

06.12.2007
Øivind Øines has shown in his Ph. D. thesis that the sea louse, a parasitic copepod, is widely distributed among wild fish species along the Norwegian coast.

The parasite is found in large numbers in the lumpfish, which is now considered to be one of the primary hosts of the parasite. The lumpfish in turn infects several types of farmed fish when it comes into the coast during the spring months.


Lumpfish infected with more than 600 sea lice (Caligus elongatus). Photo: Øivind Øines

Øivind Øines studied sea lice infestations in wild fish for his Ph. D. degree. Using genetic tools, he discovered more information about the pathways of infection and sources of infestation of this important fish parasite. By increasing our understanding of the patterns of infection of sea lice, Øines’ work may prove significant both for the fish farming industry along the coast and for combating the parasite.

The sea louse Caligus elongatus is a parasite that attaches to the skin of fish. It can cause sores on its host, which at worst may prove fatal to the fish. It has been found on more than eighty different fish species in most or the world’s oceans. Sea lice also infect farmed fish and have been reported in large numbers on farmed salmonids at sea, but also on other farmed species such as cod and halibut.

“Since sea lice are found on so many different north-Atlantic fish species, it is highly likely that they can transmit from wild fish to farmed fish. Our genetic studies of the parasite also support this. It is also likely that they can transmit between different farmed species”, says Øivind Øines.

During his doctoral work, Øines developed genetic tools for the identification of these parasites and other related parasitic copepods, which may be nearly identical in appearance during several stages of their life cycles. Øines found two different genetic variants of the sea louse on wild fish, each of which appears to have different patterns of infestation.

Øines shows in his thesis that the sea louse is relatively common among wild fish. Fifteen per cent of wild fish were infected with this parasite outside Arendal during the period 2002 – 2004, which was the area for the field studies. Øines’ studies have revealed in all likelihood how both wild fish and farmed fish become infected, and identified some of the most important probable sources of infection in the ocean.

Dr. Scent. Øivind Øines defended his thesis on December 4, 2007, for the degree of Doctor Scientiarum at the Norwegian School of Veterinary Science with the title: Host selection and infection strategies in Caligus elongatus.

The work was carried out in regii of the Norwegian Veterinary Institute in close collaboration with other researchers at the Institute of Marine Research at Flødevigen, and at the University of Oslo.

Magnhild Jenssen | alfa
Further information:
http://www.veths.no
http://www.veths.no/105/English/7899/The-sea-louse-a-common-parasite-of-wild-fish/

More articles from Ecology, The Environment and Conservation:

nachricht Joint research project on wastewater for reuse examines pond system in Namibia
19.12.2016 | Technische Universität Darmstadt

nachricht Scientists produce a new roadmap for guiding development & conservation in the Amazon
09.12.2016 | Wildlife Conservation Society

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

Im Focus: Newly proposed reference datasets improve weather satellite data quality

UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration

"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Multiregional brain on a chip

16.01.2017 | Power and Electrical Engineering

New technology enables 5-D imaging in live animals, humans

16.01.2017 | Information Technology

Researchers develop environmentally friendly soy air filter

16.01.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>