Changes

==Introduction==

==Introduction==

[[File:Argulus.jpg|250px|thumb|right|'''Fish Louse (''Argulus sp.'') attached to the skin of a fish (Wikimedia Commons)''']]

[[File:Argulus.jpg|250px|thumb|right|'''Fish Louse (''Argulus sp.'') attached to the skin of a fish (Wikimedia Commons)''']]

The '''fish louse''' is a '''metazoan [[Crustacea|crustacean]] skin parasites''' of '''freshwater fish'''. They pose a major threat to teh health of commercially produced fish.

The '''fish louse (''Argulus spp.'')''' is a '''metazoan [[Crustacea|crustacean]] skin parasites''' of '''freshwater fish'''. They pose a major threat to the health of commercially produced fish.

==Life Cycle==

==Life Cycle==

The louse has a sharp stylet along the ventral midline that it uses to pierce the skin of the fish. It then '''injects digestive enzymes''' into the surrounding tissues and feeds on the digested bodily fluids by sucking them out with its '''proboscis'''.  

The louse has a sharp stylet along the ventral midline that it uses to pierce the skin of the fish. It then '''injects digestive enzymes''' into the surrounding tissues and feeds on the digested bodily fluids by sucking them out with its '''proboscis'''.  

The damage caused by the fish louse is two-fold; firstly '''localised inflammation and irritation''' of the skin caused directly by the parasite and secondarily the risk of developing'''opportunistic infections''', both '''bacterial and viral''' directly through the damaged skin. [[Pseudomonas species - Overview|''Pseudomonas spp.'']] and [[Aeromonas species - Overview|''Aeromonas spp.'']] are often of particular concern, as they can potentially invade the [[Gills|gills]].

The damage caused by the fish louse is two-fold; firstly '''localised inflammation and irritation''' of the skin caused directly by the parasite and secondarily the risk of developing '''opportunistic infections''', both '''bacterial and viral''' via the damaged skin. [[Pseudomonas species - Overview|''Pseudomonas spp.'']] and [[Aeromonas species - Overview|''Aeromonas spp.'']] are often of particular concern, as they can potentially invade the [[Gills|gills]].

Fish may show '''rubbing and flashing behaviour''' due to the intense irritation caused by the infection.

Fish may show '''rubbing and flashing behaviour''' due to the intense irritation caused by the infection.

==Treatment==

==Treatment==

It is vital that any treatment plan is effective against both adults and juvenile stages of the parasite.

It is vital that any treatment plan is effective against both '''adults and juvenile stages''' of the parasite.

   

   

Infestations can be treated with an '''increase in water salinity'''. If this is ineffective, [[Ectoparasiticides|ectoparasiticides]] such as '''organophosphates''' or [[Ectoparasiticides#Modes of Action|'''chitin inhibitors''']] can be used. Three treatments of OPs are usually required to eliminate all life stages. It should be noted that organophosphate treatment is not permitted in the UK and should be confirmed in any other region before use.  

Infestations can be treated with an '''increase in water salinity'''. If this is ineffective, [[Ectoparasiticides|ectoparasiticides]] such as '''organophosphates''' or [[Ectoparasiticides#Modes of Action|'''chitin inhibitors''']] can be used. Three treatments of organophosphates are usually required to eliminate all life stages. It should be noted that organophosphate treatment is not permitted in fish in the UK and should be confirmed in any other region before use.  

{{Learning

{{Learning

Fishdoc (2009) '''Argulus/Fish Louse''' at http://www.fishdoc.co.uk/disease/argulus.htm, accessed online 22/11/2011

Fishdoc (2009) '''Argulus/Fish Louse''' at http://www.fishdoc.co.uk/disease/argulus.htm, accessed online 22/11/2011

Frye, F. L & Williams, D. L (1995) '''Self-Assessment Colour Review - Reptiles & Amphibians''' ''Manson''

Lewbart, G. A. (1998) '''Self-Assessment Colour Review of Ornamental Fish''' ''Manson''

Maclean, B (2006) '''Common dermatoses of ornamental fish and amphibians''' ''In Practice 2006 28: 604-613''

Maclean, B (2006) '''Common dermatoses of ornamental fish and amphibians''' ''In Practice 2006 28: 604-613''

Stuart, N (1988) '''Common skin diseases of farmed and pet fish''' ''In Practice 1988 10: 47-53''

Stuart, N (1988) '''Common skin diseases of farmed and pet fish''' ''In Practice 1988 10: 47-53''

Wildgoose, W (1998) '''Skin disease in ornammental fish: identifying common problems''' ''In Practice 1998 20: 226-243''

Wildgoose, W (1998) '''Skin disease in ornamental fish: identifying common problems''' ''In Practice 1998 20: 226-243''

[[Category:To Do - Manson review]]

 

{{review}}

 

[[Category:Crustacea]]

[[Category:Crustacea]]

[[Category:Fish Diseases]]

[[Category:Fish Diseases]]