scholarly journals Sustainable production and use of cleaner fish for the biological control of sea lice: recent advances and current challenges

2018 ◽  
Vol 183 (12) ◽  
pp. 383-383 ◽  
Author(s):  
Adam J Brooker ◽  
Athina Papadopoulou ◽  
Carolina Gutierrez ◽  
Sonia Rey ◽  
Andrew Davie ◽  
...  
Keyword(s):  
Life Histories ◽  
Control Strategies ◽  
Disease Outbreaks ◽  
Basic Knowledge ◽  
Sea Lice ◽  
Suitable Habitat ◽  
Farmed Fish ◽  
Marine Aquaculture ◽  
Cleaner Fish ◽  
Labrus Bergylta

Currently, cleaner fish are one of the most widely used sea lice control strategies in Atlantic salmon aquaculture. Two species are currently being farmed in North Atlantic countries, ballan wrasse (Labrus bergylta) and lumpfish (Cyclopterus lumpus), and the sector in most countries is rapidly expanding towards self-sufficiency. The species are very different both in terms of their biology and life histories and, consequently, production and husbandry methods must be tailored to each species. There are numerous health challenges currently experienced in both species, with bacterial and parasitic diseases being the most prevalent, and cohabitation with salmon may increase the risk of disease. Good husbandry and routine health monitoring are essential, although treatment is often required when disease outbreaks occur. Ballan wrasse and lumpfish are both proven to be effective salmon delousers, although delousing efficacy can be variable in farmed fish; the provision of suitable habitat and acclimation to net-pen conditions may encourage natural behaviours, including delousing, and the use of operational welfare indicators can highlight potential welfare issues. Cleaner fish research is progressing rapidly, although much of the basic knowledge regarding the species’ biology remains unknown. The simultaneous domestication of two new marine aquaculture species is a significant challenge demanding sustained effort and funding over a prolonged period of time. Research must focus on enhancing the robustness of the farmed stocks and increasing hatchery outputs to meet the urgent demands from the salmon sector and protect wild stocks from overfishing.

scholarly journals Cleaner fish escape salmon farms and hybridize with local wrasse populations

2018 ◽  
Vol 5 (3) ◽  
pp. 171752 ◽  
Author(s):  
Ellika Faust ◽  
Kim Tallaksen Halvorsen ◽  
Per Andersen ◽  
Halvor Knutsen ◽  
Carl André
Keyword(s):  
Range Expansion ◽  
First Generation ◽  
Leading Edge ◽  
Sea Lice ◽  
Fish Farms ◽  
Farmed Fish ◽  
Cleaner Fish ◽  
Local Populations ◽  
Genetic Impact ◽  
Generation Hybrid

The genetic impact of farmed fish escaping aquaculture is a highly debated issue. However, non-target species, such as cleaner fish used to remove sea lice from farmed fish, are rarely considered. Here, we report that wild corkwing wrasse ( Symphodus melops ), which are transported long distances to be used as cleaner fish in salmon farms, escape and hybridize with local populations. Recently, increasing numbers of corkwing wrasse have been reported in Flatanger in Norway, north of its described distribution range, an area heavily relying on the import of cleaner fish from Skagerrak. Using genetic markers identified with 2bRAD sequencing, we show that, although the Flatanger population largely is a result of a northward range expansion, there is also evidence of considerable gene flow from southern populations in Skagerrak and Kattegat. Of the 40 corkwing wrasses sampled in Flatanger, we discovered two individuals with clear southern genotypes, one first-generation hybrid, and 12 potential second-generation hybrids. In summary, we provide evidence that corkwing wrasse escape from fish farms and hybridize with local populations at the leading edge of an ongoing range expansion. Although the magnitude and significance of escapees warrant further investigation, these results should be taken into consideration in the use of translocated cleaner fish.

scholarly journals COEVOLUTION WITH SPATIALLY STRUCTURED RICE LANDRACES MAINTAINS MULTIPLE GENERALIST LINEAGES IN THE RICE BLAST PATHOGEN

2021 ◽  
Author(s):  
Sajid Ali ◽  
Pierre Gladieux ◽  
Sebastien Ravel ◽  
Henri Adreit ◽  
Isabelle Meusnier ◽  
...  
Keyword(s):  
Rice Blast ◽  
Life Histories ◽  
Control Strategies ◽  
Indica Rice ◽  
Disease Outbreaks ◽  
Population Subdivision ◽  
Disease Dynamics ◽  
Rice Landraces ◽  
Scale Population ◽  
Significant Disease

Traditional agrosystems, where humans, crops and microbes have coevolved over long periods, can serve as models to understand the eco-evolutionary determinants of disease dynamics and help the engineering of durably resistant agrosystems. Here, we investigated the genetic and phenotypic relationship between rice (Oryza sativa) landraces and their rice blast pathogen (Magnaporthe oryzae) in the traditional Yuanyang terraces of flooded rice paddies in China, where rice landraces have been grown and bred over centuries without significant disease outbreaks. Analyses of genetic subdivision revealed that indica rice plants clustered according to landrace names. Three new diverse lineages of rice blast specific to the Yuanyang terraces coexisted with lineages previously detected at the worldwide scale. Population subdivision in the pathogen population did not mirror pattern of population subdivision in the host. Measuring the pathogenicity of rice blast isolates on landraces revealed generalist life histories. Our results suggest that the implementation of disease control strategies based on the emergence or maintenance of a generalist lifestyle in pathogens may sustainably reduce the burden of disease in crops.

scholarly journals Emamectin Benzoate Treatment of Hybrid Grouper Infected With Sea Lice in Hong Kong

2021 ◽  
Vol 8 ◽  
Author(s):  
Sophie St-Hilaire ◽  
Tzu Hsuan Cheng ◽  
Stephen Chi Ho Chan ◽  
Chi Fai Leung ◽  
Ka Man Chan ◽  
...  
Keyword(s):  
Hong Kong ◽  
Preliminary Evidence ◽  
Sea Lice ◽  
Emamectin Benzoate ◽  
Farmed Fish ◽  
Marine Aquaculture ◽  
Oral Infections ◽  
Hybrid Grouper ◽  
The World ◽  
Lice Infestations

Sea lice (Copepoda: Caligidae) are ectoparasites which negatively impact marine aquaculture species around the world. There are a limited number of treatments licensed for use against sea lice in tropical and semi-tropical farmed fish species. Emamectin benzoate (EB) was an effective pharmaceutical drug against sea lice infestations in several salmon industries before resistance to the product developed. This drug has not been extensively tested in marine fish within Asia. The objective of this study was to determine whether this drug could be used to treat oral infections with sea lice in hybrid grouper (Mycteroperca tigris × Epinephelus lanceolatus) cultured in saltwater net-pen sites in Hong Kong. We observed an overall reduction in sea lice infections over time, starting on the last day of the treatment up to the end of our study (i.e., 14 days after the last EB treatment). We also observed a large variation in concentrations of EB in fish on the last day of the treatment, which provides an explanation for the variation in response to the treatment. It also suggests that distribution of the medication to fish in saltwater net-pens is difficult, especially when medication is hand-mixed in the feed and possibly unevenly distributed in the daily rations. Overall, this study provides preliminary evidence that EB could be used to treat sea lice found in Hong Kong and potentially in other regions of SE Asia.

Caligids-potential pathogens for marine finfish aquaculture in Mexico?

2017 ◽  
Vol 44 (3) ◽  
pp. 433-441
Author(s):  
Francisco Neptalí Morales-Serna ◽  
Juan Manuel Martínez-Brown ◽  
Rosa Maria Medina-Guerrero ◽  
Emma Josefina Fajer-Ávila
Keyword(s):  
Coastal Waters ◽  
Host Location ◽  
Current Knowledge ◽  
Control Strategies ◽  
Sea Lice ◽  
Ecological Studies ◽  
Parasitic Copepods ◽  
The Family ◽  
And Control ◽  
Finfish Aquaculture

Parasitic copepods of the family Caligidae, the so-called sea lice, may be deleterious to marine or brackish finfish aquaculture. To date, biological and ecological studies of sea lice have been mostly restricted to species from cold or temperate regions. In Mexico there are some records of sea lice species on marine fishes; however, the research regarding their biology and ecology has been scarce. It is possible that a high biodiversity of sea lice is distributed in coastal waters of Mexico; therefore, their significance as pathogenic parasites should increase. The purpose of this review is to outline the current knowledge of the life cycle, host location, ecology, effect on fish health, and control strategies of sea lice in order to establish supportive basis for natural resource management and control of parasites and diseases of marine fish cultured in Mexico.

scholarly journals Perfuorooctane Sulfonate (PFOS), Perfluorooctanoic Acid (PFOA), Brominated Dioxins (PBDDs) and Furans (PBDFs) in Wild and Farmed Organisms at Different Trophic Levels in the Mediterranean Sea

Toxics ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 50 ◽  
Author(s):  
Elena Fattore ◽  
Renzo Bagnati ◽  
Andrea Colombo ◽  
Roberto Fanelli ◽  
Roberto Miniero ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Limit Of Detection ◽  
Perfluorooctanoic Acid ◽  
Trophic Levels ◽  
Sea Bream ◽  
Farmed Fish ◽  
European Sea Bass ◽  
Marine Aquaculture ◽  
Fishery Products ◽  
The Mediterranean

The present study shows the results of perfuorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), brominated dioxins (PBDDs) and furans (PBDFs) measured in several marine fish and seafood of commercial interest at different trophic levels of the food chain. The aims were to investigate the level of the contamination in Mediterranean aquatic wildlife, and in farmed fish, to assess human exposure associated to fishery products consumption. Samples of wild fish were collected during three different sampling campaigns in different Food and Agriculture Organization (FAO) 37 areas of the Mediterranean Sea. In addition, farmed fish (gilthead sea bream and European sea bass) from off-shore cages from different marine aquaculture plants. Results showed contamination values of PFOS and PFOA were lower than those detected in sea basins other than the Mediterranean Sea. Concentration values of PFOS were generally higher than those of PFOA; moreover, levels in farmed fish were lower than in wild samples from the Mediterranean Sea. Intake of PFOS and PFOA through fishery products consumption was estimated to be 2.12 and 0.24 ng/kg·BW·day, respectively, for high consumers (95th percentile). Results of 2,3,7,8-substituted congeners of PBDDs and PBDFs were almost all below the limit of detection (LOD), making it difficult to establish the contribution of these compounds to the total contamination of dioxin-like compounds in fish and fishery products.

scholarly journals Relative Importance of Cleaning Behaviour in Centrolabrus Exoletus and other Wrasse at Arrábida, Portugal

1997 ◽  
Vol 77 (3) ◽  
pp. 891-898 ◽  
Author(s):  
Miguel Henriques ◽  
Vitor C. Almada
Keyword(s):  
Reef Fishes ◽  
Relative Importance ◽  
Cleaner Fish ◽  
Cleaning Behaviour ◽  
North Eastern ◽  
In Captivity ◽  
Tropical Reef ◽  
Ctenolabrus Rupestris ◽  
Labrus Bergylta ◽  
Host Fishes

Underwater behavioural observations were conducted to evaluate the relative importance of cleaning behaviour in three species of common north-eastern Atlantic wrasse (Teleostei: Labridae). At the study site, the only cleaner was Centrolabrus exoletus. A total of 12 species was cleaned, with the wrasse, Symphodus melops and Labrus bergylta being the species most frequently cleaned. Neither S. melops nor Ctenolabrus rupestris, known to be cleaners in other sites or in captivity, could be observed cleaning other fishes. Centrolabrus exoletus was found to be a facultative cleaner fish with cleaning acts representing only 7% of the observed feeding acts. In focal observations of host fishes, the incidence of cleaning acts reached a level (11 h-1 per host) similar to that reported for tropical reef fishes and probably reflects the high numbers of cleaners available. Some factors that may affect the origin of the cleaning interactions are discussed.

scholarly journals Innovative Distance Learning Tool for Morphological Identification of Chigger Mites (Actinotrichida) as Vectors of Scrub Typhus: A Pilot Study

2020 ◽  
Vol 5 (2) ◽  
pp. 55
Author(s):  
Rawadee Kumlert ◽  
Aulia Rahmi Pawestri ◽  
Piyada Linsuwanon ◽  
Serge Morand
Keyword(s):  
Distance Learning ◽  
Scrub Typhus ◽  
Control Strategies ◽  
Extracellular Fluid ◽  
Basic Knowledge ◽  
Effective Control ◽  
Average Score ◽  
Morphological Identification ◽  
Learning Method ◽  
Learning Tool

Scrub typhus, a disease caused by Orientia tsutsugamushi, affects more than one billion people globally with an average fatality rate of 6%. Humans are accidentally infected through the bite of trombiculid mite larvae (chiggers). Chiggers feed on hosts’ extracellular fluid for survival and development. O. tsutsugamushi is maintained throughout the chigger’s lifespan and over several generations. Although disease-related knowledge is essential in designing effective control strategies, many personnel in related sectors are unfamiliar with this disease and its vector. To tackle this issue, we developed a distance learning tool using educational videos on scrub typhus- and vector-related topics. The learning method is facilitated online, and students and tutors are not required to be physically present at the same place and time, thus allowing flexibility and accessibility. Knowledge improvement of 34 participants from related sectors was evaluated by pre- and post-test questionnaires. Although 54% of participants had prior knowledge of scrub typhus, 76.5% still lack basic knowledge of vector identification. After the distance learning, the average score increased significantly from the baseline (p < 0.05). Most participants showed interest in the topic and learning method. These results suggest that the distance learning method was promising in distributing health-related information and might be applied to other diseases and communities.

scholarly journals Mosquitoes of Etiological Concern in Kenya and Possible Control Strategies

Insects ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 173 ◽  
Author(s):  
Samuel Karungu ◽  
Evans Atoni ◽  
Joseph Ogalo ◽  
Caroline Mwaliko ◽  
Bernard Agwanda ◽  
...  
Keyword(s):  
Environmental Changes ◽  
Mosquito Control ◽  
Control Strategies ◽  
Mosquito Species ◽  
Disease Outbreaks ◽  
Health Concern ◽  
Public Health Concern ◽  
Vector Management ◽  
Invasive Mosquito ◽  
Parasitic Pathogens

Kenya is among the most affected tropical countries with pathogen transmitting Culicidae vectors. For decades, insect vectors have contributed to the emergence and distribution of viral and parasitic pathogens. Outbreaks and diseases have a great impact on a country’s economy, as resources that would otherwise be used for developmental projects are redirected to curb hospitalization cases and manage outbreaks. Infected invasive mosquito species have been shown to increasingly cross both local and global boarders due to the presence of increased environmental changes, trade, and tourism. In Kenya, there have been several mosquito-borne disease outbreaks such as the recent outbreaks along the coast of Kenya, involving chikungunya and dengue. This certainly calls for the implementation of strategies aimed at strengthening integrated vector management programs. In this review, we look at mosquitoes of public health concern in Kenya, while highlighting the pathogens they have been linked with over the years and across various regions. In addition, the major strategies that have previously been used in mosquito control and what more could be done to reduce or combat the menace caused by these hematophagous vectors are presented.

scholarly journals Biofouling on Salmon Pen Nets and Cleaner Fish Shelters Does Not Harbor Planktonic Stages of Sea Lice

2020 ◽  
Vol 7 ◽  
Author(s):  
Lone S. Jevne ◽  
Margrete S. Øvrelid ◽  
Andreas Hagemann ◽  
Nina Bloecher ◽  
Kristine B. Steinhovden ◽  
...  
Keyword(s):  
Sea Lice ◽  
Cleaner Fish
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