scholarly journals The protective effect of the Phe362Tyr mutation in salmon lice’ (Lepeophtheirus salmonis) AChE when exposed to full-scale azamethiphos bath treatments

Aquaculture ◽  
2019 ◽  
Vol 505 ◽  
pp. 517-522 ◽  
Author(s):  
Kari Olli Helgesen ◽  
Kristoffer Røyset ◽  
Vidar Aspehaug ◽  
Peder A. Jansen
Keyword(s):  
Protective Effect ◽  
Full Scale ◽  
Lepeophtheirus Salmonis ◽  
Salmon Lice

scholarly journals Salmon lice evasion, susceptibility, retention, and development differ amongst host salmonid species

2017 ◽  
Vol 75 (3) ◽  
pp. 1071-1079 ◽  
Author(s):  
Samantha Bui ◽  
Elina Halttunen ◽  
Agnes M Mohn ◽  
Tone Vågseth ◽  
Frode Oppedal
Keyword(s):  
Atlantic Salmon ◽  
Chinook Salmon ◽  
Salmo Trutta ◽  
Parasite Development ◽  
Lepeophtheirus Salmonis ◽  
Sea Trout ◽  
Salmon Lice ◽  
Salmonid Species ◽  
Host Parasite ◽  
Temporal Overlap

Abstract With different ecological characteristics amongst salmonid species, their response to parasitic infestation is likely to vary according to their spatial and temporal overlap with the parasite. This study investigated the host–parasite interactions amongst three species of salmonids and the ectoparasitic salmon louse, Lepeophtheirus salmonis. To determine any variation in infestation parameters amongst salmonids, single population groups of Atlantic salmon (Salmo salar), chinook salmon (Onchorhynchus tshawytscha), and previously-infested and naïve sea trout (Salmo trutta) were exposed to a controlled infestation challenge. We found that chinook salmon and both sea trout groups were more susceptible to acquiring lice than Atlantic salmon. Behavioural responses during infestation were more pronounced in Atlantic and chinook salmon. Parasite development was similar in lice attached to Atlantic salmon and sea trout, but hindered on chinook salmon. At 16 days post-infestation, chinook salmon had reduced lice loads to the same level as Atlantic salmon, whilst sea trout retained their lice. These results demonstrate differences in interactions with L. salmonis amongst these species, and highlight the vulnerability of sea trout to infestation.

scholarly journals Effects of salmon lice Lepeophtheirus salmonis on wild sea trout Salmo trutta—a literature review

2015 ◽  
Vol 7 (2) ◽  
pp. 91-113 ◽  
Author(s):  
EB Thorstad ◽  
CD Todd ◽  
I Uglem ◽  
PA Bjørn ◽  
PG Gargan ◽  
...  
Keyword(s):  
Literature Review ◽  
Salmo Trutta ◽  
Lepeophtheirus Salmonis ◽  
Sea Trout ◽  
Salmon Lice

Thermal delousing in anaesthetised small Atlantic salmon (Salmo salar) post-smolts: A case study showing the viability of anaesthesia prior to delousing for improved welfare during treatment for salmon lice

2021 ◽  
Vol 30 (2) ◽  
pp. 117-120
Author(s):  
O Folkedal ◽  
SO Utskot ◽  
J Nilsson
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Experimental Research ◽  
Acute Stress ◽  
Small Scale ◽  
Lepeophtheirus Salmonis ◽  
Salmon Lice ◽  
Sequence Of Events ◽  
Present Case Study

Delousing treatment for salmon sea lice (Lepeophtheirus salmonis) is considered a significant welfare concern in farming of Atlantic salmon ( Salmo salar), where both industry and legislative bodies prompt for better methods. Currently, the most common method is thermal delousing, where fish are crowded, pumped into a vessel and exposed to ∼28–34°C for ∼30 s. Physical collisions occurring as a result of a loss of behavioural control lead to acute stress. Crowding triggers vigorous escape behaviour as salmon respond not only to treatment but also to being channeled to and from the treatment zone. A sequence of events considered to cause mortality and poor welfare. The present case study was motivated by an urgent need for delousing in groups of small salmon post-smolts in experimental research. For this purpose, a simple, small-scale system for thermal delousing was constructed, including anaesthesia to alleviate behavioural responses. The anaesthetised fish showed little behavioural response to thermal treatment, strong appetite within hours, and negligible mortality. The described method is regarded as a welfare-friendly alternative to industrial delousing in smaller fish groups, for example, in experimental research. We would encourage detailed research aimed towards gaining a deeper under-standing of the welfare effects of anaesthesia prior to treatment for delousing.

The Ecology of Juvenile Salmon in the Northeast Pacific Ocean: Regional Comparisons

2007 ◽  
Keyword(s):  
Coastal Waters ◽  
Pacific Salmon ◽  
Size Class ◽  
Small Fish ◽  
Lepeophtheirus Salmonis ◽  
Northeast Pacific ◽  
Salmon Lice ◽  
Regional Comparisons ◽  
Northeast Pacific Ocean ◽  
Over Time

Abstract.—We report patterns of infestation with motile salmon lice, <em>Lepeophtheirus salmonis</em>, on Pacific salmon collected with a surface trawl in coastal waters of Oregon, Washington, British Columbia, and Alaska during 2002 and 2003. Salmon lice were observed on all salmon species examined and in all areas surveyed. The prevalence and abundance of lice infestation varied significantly among species, size-classes, seasons, regions, and years, with larger salmon being consistently more heavily infested than small salmon. The number of lice infesting the small size-class (100–400 mm) of salmon rarely exceeded 5 lice per fish with a mean abundance generally below 0.2 lice per fish. Lice prevalence and, to a lesser extent, lice abundance increased over time in small fish, with lower values during spring and higher values in the following winter, and continued to increase in larger and older fish. There were no apparent effects of water temperature on lice infestation in Pacific salmon. This study suggested that salmon infested with lice remained in coastal waters throughout the year. We suggest that lice on salmon that overwinter in coastal waters will contribute to a pool of infective copepodids in these habitats.

The development of salmon lice (Lepeophtheirus salmonis) on artificially infected post smolts of sea trout (Salmo trutta)

1998 ◽  
Vol 76 (5) ◽  
pp. 970-977 ◽  
Author(s):  
Pål Arne Bjørn ◽  
Bengt Finstad
Keyword(s):  
Salmo Trutta ◽  
Adult Stage ◽  
Infection Intensity ◽  
Developmental Rate ◽  
Infected Fish ◽  
Random Pattern ◽  
Lepeophtheirus Salmonis ◽  
Skin Damage ◽  
Sea Trout ◽  
Salmon Lice

The developmental rate, distribution on the host, and pathogenicity (skin damage) of salmon lice (Lepeophtheirus salmonis) were tested on artificially infected sea trout (Salmo trutta) post smolts. Male lice developed faster than females, taking approximately 29 and 38 days, respectively, to reach the adult stage at 10°C. During this time, infection intensity decreased. Less than 40% of the lice reached the adult stage, and their distribution changed from overdispersed towards a more random pattern. The chalimus larvae of the lice exhibited a preference for the gills and fins, especially the dorsal fin, and caused only minor skin damage. When the preadult and adult stages appeared, skin damage became severe, especially on the preferred head and dorsal areas, causing mortality of the most heavily infected fish.

scholarly journals Salmon lice (Lepeophtheirus salmonis) development times, body size, and reproductive outputs follow universal models of temperature dependence

2016 ◽  
Vol 73 (12) ◽  
pp. 1841-1851 ◽  
Author(s):  
Francisca Samsing ◽  
Frode Oppedal ◽  
Sussie Dalvin ◽  
Ingrid Johnsen ◽  
Tone Vågseth ◽  
...  
Keyword(s):  
Body Size ◽  
Temperature Dependence ◽  
Low Temperatures ◽  
Lepeophtheirus Salmonis ◽  
Infective Stage ◽  
Adult Body Size ◽  
Universal Models ◽  
Salmon Lice ◽  
Development Times ◽  
Adult Body

Temperatures regulate metabolism of marine ectotherms and thereby influence development, reproduction, and, as a consequence, dispersal. Despite the importance of water temperatures in the epidemiology of marine diseases, for the parasitic copepod Lepeophtheirus salmonis, the effect of high and low temperatures has not been methodically investigated. Here, we examined the effects of a wide temperature range (3–20 °C) on L. salmonis larval development, adult body size, reproductive outputs, and infestation success. Further, we tested if dispersal of salmon lice differed with two temperature-dependent development times to the infective stage (30 and 60 degree-days) using an individual-based dispersal model. Development times followed universal models of temperature dependence described for other marine ectotherms. Water temperatures had a negative relationship with development times, adult body size, and reproductive outputs, except at 3 °C, where larvae failed to reach the infective stage and all parameters were decreased, indicating low temperatures are more detrimental than high temperatures. The predictable effect of temperatures on lice development and reproduction will have important applications, such as predicting dispersal and population connectivity, to assist in controlling lice epidemics.

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