Cleaner Fish Research Articles

Multi-Organ Transcriptome Response of Lumpfish (Cyclopterus lumpus) to Aeromonas salmonicida Subspecies salmonicida Systemic Infection.

Lumpfish is utilized as a cleaner fish to biocontrol sealice infestations in Atlantic salmon farms. Aeromonas salmonicida, a Gram-negative facultative intracellular pathogen, is the causative agent of furunculosis in several fish species, including lumpfish. In this study, lumpfish were intraperitoneally injected with different doses of A. salmonicida to calculate the LD50. Samples of blood, head-kidney, spleen, and liver were collected at different time points to determine the infection kinetics. We determined that A. salmonicida LD50 is 102 CFU per dose. We found that the lumpfish head-kidney is the primary target organ of A. salmonicida. Triplicate biological samples were collected from head-kidney, spleen, and liver pre-infection and at 3- and 10-days post-infection for RNA-sequencing. The reference genome-guided transcriptome assembly resulted in 6246 differentially expressed genes. The de novo assembly resulted in 403,204 transcripts, which added 1307 novel genes not identified by the reference genome-guided transcriptome. Differential gene expression and gene ontology enrichment analyses suggested that A. salmonicida induces lethal infection in lumpfish by uncontrolled and detrimental blood coagulation, complement activation, inflammation, DNA damage, suppression of the adaptive immune system, and prevention of cytoskeleton formation.

Cultivated meat as a tool for fighting antimicrobial resistance.

Antibiotic use in livestock and aquaculture production is driving resistance to medically important antibiotics. Producing meat through alternative methods, such as cultivated meat, offers an opportunity to decouple antibiotics from meat.

Moving cleaner fish from the wild into fish farms: A zero-sum game?

Fish that engage in mutualistic cleaning behaviour (‘cleaner fishes’) have recently been popularized as a nature-based method of controlling ectoparasite outbreaks in fish farms. Outbreaks impact animal welfare and threaten wild fish populations; due to this, millions of cleaner fish (especially wrasses from the family Labridae) are wild-caught each year and transferred into Atlantic salmon (Salmo salar) farms to remove ectoparasitic sea lice (predominantly Lepeophtheirus salmonis) from farmed salmon and reduce spillover (i.e. parasites transferring from farmed to wild fish) onto vulnerable wild salmonid populations. However, we hypothesize that this practice may result in no net benefit to the infestation pressure on wild fish if gains in farm-based control trade off against the removal of lice from wild fish by wrasse moved from the wild into net pens. Such a scenario would entail a zero-sum game. We test our hypothesis using an ecological simulation of wrasse as cleaners of farmed Atlantic salmon and wild sea trout (Salmo trutta). We parameterized our simulation based on published models of sea lice epidemics from farms to calculate the relative impact of lice when wrasse are removed from the ecosystem to serve as cleaners. Our simulations revealed that a zero-sum game can emerge from this system at unexpectedly infrequent rates of cleaning by wrasse in the wild. Scandinavian wrasses are relatively data poor and parameterizing our simulation revealed a need for better data on the ecological role of these fishes in coastal ecosystems. For the first time, we suggest that wrasse fisheries may be a zero-sum game and that under a plausible set of conditions, fishing wrasse out of coastal ecosystems may do more harm than good for modulating sea lice epidemics. However, we emphasize that these results do not suggest that wrasse alone will play a role in resolving high infestation pressure of lice emanating from fish farms.

Comparing Body Density of Lumpfish (Cyclopterus lumpus) to Different Operational Welfare Indicators

Farmed lumpfish (Cyclopterus lumpus) are commonly used as cleaner fish in the salmonid aquaculture industry, but a knowledge gap exists with regards to their body density. Filling this knowledge gap is of importance, as the lumpfish has no swim bladder and thus relies on alternative methods for buoyancy, i.e., the body density difference between the fish and its surroundings. The aims of this study were to measure the body density of lumpfish and investigate the correlation between body density and different operational welfare indicators. A total of 138 lumpfish were sampled at five different aquaculture sites situated in the Faroe Islands. Weight in water and air was measured, body density was calculated, and operational welfare was assessed. The average body density of the juvenile lumpfish was 1.030 g mL−1. Fulton’s K, stomach score, and length were negatively correlated to body density, while the hepatosomatic index was positively correlated to body density. Liver colour was correlated to body density, but the groupings were too broad for a final definitive conclusion. The knowledge gained from this study might help the industry improve their understanding of the operational welfare indicators used for lumpfish. Additionally, the knowledge might also help the aquaculture industry improve their husbandry and feeding practices.

Healthier Meat Products Are Fashionable—Consumers Love Fashion

Meat manufacturers are nowadays in a very unenviable position. Both meat and meat products require the utilization of various additives due to their chemical composition. On the other hand, consumers demand fresh, additive-free, and high-quality products with extended shelf-life, which might be considered as healthier, even functional food. These facts push manufacturers and researchers in pursuit of modern technologies and supplements to meet these high demands. Since a high daily intake of sodium and fat might cause severe health issues, reducing these ingredients in meat products is the first task towards healthier food. Sodium can be reduced by ultrasound, high-pressure processing, pulsed electric field, and replacement of NaCl with KCl, calcium gluconate, calcium glycerophosphate, calcium lactate, and monosodium glutamate. The reduction of the fat content can be achieved through a decrease in the amount of fatty tissue in the inital mixture and/or replacement with non-lipid components, or by partial fatty tissue replacement with oils rich in polyunsaturated fatty acids. Utilization of plant proteins (soy, wheat gluten, pea, chickpea, lentil, potato, barley, oat, rice, etc.), mycoproteins or micro-algae proteins, plant fats (palm and coconut fat, canola, sunflower, soy and corn oil, etc.), and polysaccharides (starches, fibers), accompanied by a meat-like fibrous structure, resulted in delicious “meat” products, which are considered a healthier alternative to real meat. Growing interest in the replacement of potentially adverse synthetic meat additives favors the use of plant (herb, fruit and vegetable) extracts, as an endless source of bioactive substances with strong antioxidant and antimicrobial activities. These extracts can be used either in raw meat or meat products, as well as in the fodder. Reformulation strategies strengthen and ensure the willingness of consumers to pay a higher price for their own demands regarding the naturalness of synthetic, clean-labeled, additive-free meat products. After a gradual alignment with strategic national/international recommendations and legal/sub-legal frameworks, the added value of such meat products opens wide the door to new segments/entire markets.

Segi Sanitasi pada Pendaratan Ikan Tuna di Pelabuhan Perikanan Samudera Bungus, Sumatra Barat

Clean and hygienic fish landings to meet sanitation requirements and guarantee the quality of the fish caught are an important part of the role of the fishing ports. However, it has not been done much at Bungus PPS, which was marked by the handling of fish quality that was not standardized, some unloading equipment and transportation facilities were rarely cleaned, and the environmental quality at the fish landing dock was not maintained. The study aimed to evaluate the quality control level of tuna fish, the performance of fish landing sanitation, and estimate the potential losses from neglected fish landing sanitation. The study used the scoring system, p control chart analysis, regression method, and profit/loss analysis. Organoleptically, the quality of tuna landed on Bungus PPS was at 7.50‒7.77 (fresh enough to fresh). The quality of tuna was still under control, with the value of upper control limit (UCL) = 0.220, central line (CL) = 0.07 and lower control limit (LCL) = 0.000. The sanitation performance of fish landings on PPS Bungus was around 3,45 (scale 1-5). Sanitation of fish handling (x) significantly affects the quality of tuna caught (y), which was indicated by the equation y = 0,1308x + 7,175. The sanitation conditions explained that 84.4% of the tuna caught were maintained. Potential losses from neglected landing sanitation were (a) the loss of the best-selling price of tuna and (b) the cost of nutrition consultation and disease management due to damage to the nutritional content of tuna.
 
 Keywords: bungus, tuna caught, fishing port, fish landing sanitation

Indirect effects of cleaner fish Labroides dimidiatus on fish grazing per reef area and benthic community structure

Grazing fishes farm algae, and consume algae, detritus and sediment and consequently differentially modify benthic communities. Manipulations of cleaner fish Labroides dimidiatus on reefs show that cleaners affect fish abundance differently according to grazer functional group. Accordingly, whether reefs are grazed differently, with consequences for the benthos (fouling material tile−1), was tested using reefs kept free of L. dimidiatus for 10 years compared with undisturbed control reefs. We recorded on video the grazing density (bites tile−1 h−1 reef−1) on settlement tiles and the natural benthos (roving fishes only), according to territorial algal farmer (Pomacentridae) and roving grazer (Acanthuridae, Labridae, Siganidae) functional groups, and measured the accumulation of fouling material tile−1 after 10 months. Grazing density on tiles (dominated by ‘indeterminate’ farmers, and roving ‘sediment-removing’ detritivore Ctenochaetus striatus) and the natural benthos (dominated by Ct. striatus and other grazers) was not measurably affected by cleaner presence. The composition of fouling material (dominated by detritus > turf algae > sediment > other) and organic and inorganic dry weight of material tile−1 were also not measurably affected by cleaner presence. This points to resilience of the benthic community to loss of cleaners. The likely complex interactions between cleaner fish presence, grazer abundance and mobility, and the often-opposite effects of territorial farmers and roving grazers on the benthos underscore the challenge in determining indirect effects of cleaners on benthic community structure. However, a lack of cleaners has negative ramifications for fish populations and physiology and thus their loss remains problematic for client fishes.

Factors Affecting Consumers’ Cultivated Meat Purchase Intentions

Cultivated meat is an innovative product that promises to provide a consumption experience and nutritional value equivalent to conventional meat, with significantly lower negative impacts. The aim of this study is to analyze the factors that influence the purchase intention of cultivated meat. A quantitative study was conducted with 304 Brazilian consumers. The data were analyzed using structural equation modeling. The study proposed a purchase intention model with aspects related to clean production, animal welfare, food safety, naturalness and the moderating effect of food neophobia. The results showed that clean production and food safety had a positive relationship with the intention to purchase cultivated meat. The naturalness of food, on the other hand, had a negative relationship with purchase intent. Furthermore, the higher the level of food neophobia, the less important the influence of clean production became with regard to cultivated meat purchase intentions.

Entomoculture: A Preliminary Techno-Economic Assessment.

Cultured meat, or the practice of growing meat from cell culture, has been experiencing rapid advances in research and technology as the field of biotechnology attempts to answer the call to fight climate change and feed a growing global population. A major hurdle for cell-based meat products entering the market in the near-future is their price. The complex production facilities required to make such products will require advanced bioreactor systems, resources such as energy and water, and a skilled labor force, among other factors. The use of insect cells in this process is hypothesized to address some of these costs due to the characteristics that make them more resilient in cell culture when compared to traditional livestock-derived cells. To address the potential for cost savings by utilizing insect cells in the cultivation of protein-enriched foods, here we utilized a techno-economic assessment model. Three different insect cell lines were used in the model. The results indicate that insect cell lines offer potential to significantly reduce the cost per kilogram of cell cultivated meat, along with further opportunities to optimize production processes through technological advances and scaling.

Spent media analysis suggests cultivated meat media will require species and cell type optimization

Cell culture media design is perhaps the most significant hurdle currently facing the commercialization of cultivated meat as an alternative source of dietary protein. Since media optimization for a specific culture system requires a significant amount of effort and investment, a major question remaining is whether media formulations can be easily shared across multiple production schemes for cells of different species and lineages. Here, we perform spent medium analysis to compare the specific nutrient utilization of primary embryonic chicken muscle precursor cells and fibroblasts to the murine C2C12 myoblast cell line. We demonstrate that these related cell types have significantly different nutrient utilization patterns collectively and on a per-cell basis, and that many components of conventional media do not appear to be depleted by the cells. Namely, glucose was not consumed as rapidly nor as completely by the chicken muscle precursors compared to other cells overall, and there were significant differences in specific consumption rates for several other key nutrients over the first day of culture. Ultimately, our results indicate that no one medium is likely ideal and cost effective to culture multiple cell types and that novel methods to streamline media optimization efforts will be important for the industry to develop.

Escorting and chafing behaviours as potential pathways to spread pathogens among cleaner fishes and their clients

Escorting and chafing behaviours as potential pathways to spread pathogens among cleaner fishes and their clients

The marine ornamental market in Brazil (Southwestern Atlantic) frequently trades prohibited and endangered species, and threatens the ecosystem role of cleaning mutualism

The marine aquarium trade often depends on organisms collected from reef environments. However, reefs are declining because of multiple anthropogenic stressors, and sustaining functional diversity is critical for maintaining reef resilience. Collection of organisms for the aquarium trade is growing in the Southwestern Atlantic, particularly in Brazil, but there is a lack of studies on its potential ecological impacts on Brazilian reefs. Therefore, we (i) gathered data on the native fish and invertebrate species exported (2012–2018) and traded internally (2019) through governmental databases and use of the snowball method, and (ii) using interaction network analyses, assessed whether overharvesting the most targeted cleaner species would disrupt the ecological function of cleaning mutualisms. Results show that 90 % of the fish exported between 2011 and 2018 belonged to 10 species, with three of them considered cleaner and with no prohibited and endemic species. The internal trade, however, included two prohibited species, three endemics and four cleaners within its top five. For invertebrates, there were four prohibited species and three cleaners in the top ten. Removal of the three most traded cleaner fish species from the mutualistic networks severely reduced number of interactions. Therefore, unlike the external trade, the internal market of marine ornamentals in Brazil is often associated with illegal practices and targets cleaning organisms in a way that may add pressure to an already fragile environment. We argue that this scenario is a consequence of lack of ordinance and adequate policies, that need prompt reassessment.

Start-up raises funds for cell-based meat

The start-up Prolific Machines has raised $42 million to develop a cell-based meat manufacturing platform that it describes as an assembly line for biology. The company hopes to bring down the cost of cell-based meat by avoiding recombinant growth factor proteins, an expensive ingredient. Breakthrough Energy Ventures led the series A financing round, which included basketball stars, an NFL quarterback, and a celebrity chef. Prolific Machines is building a 2,300 m 2 headquarters in California.

Start-up raises funds for cell-based meat assembly line

Start-up raises funds for cell-based meat assembly line

The effects of message framing on novel food introduction: Evidence from the artificial meat products in China

Technological advances and innovations in the agri-food sector have become increasingly important over the past decade. However, as consumers often have little knowledge and information about novel food products, they are hesitant to accept them. Though the role of information on consumer decision-making for novel foods has been examined extensively, little is known about artificial meat products. This study investigated how message framing and regulatory focus (the way individuals approach pleasures and avoid pains according to the regulatory fit theory) affect Chinese consumers’ willingness to pay (WTP) for novel food products. It examined the valuation of artificial meat products using contingent valuation experiments conducted via online surveys in China. Focusing on artificial meat hamburgers, we found that both gain- and avoidance-framed messages, compared with neutral messages, could increase a consumer’s WTP when introducing novel food products, and regulatory focus had a significant effect on WTP. In general, individuals’ WTP is higher when their regulatory focus fits the product’s message framing. Finally, we identified heterogeneous effects of message framing and regulatory focus on WTP across substitutable novel food products, such as plant-based meat and clean meat hamburgers.

Through the looking glass: how do marked dolphins use mirrors and what does it mean?

Mirror-guided self-inspection is seen as a cognitive hallmark purportedly indicating the existence of self-recognition. Only a few species of great apes have been reported to pass a standard mark test for mirror self-recognition in which animals attempt to touch a mark. In addition, evidence for passing the mark test was also reported for Asian elephants, two species of corvids, and a species of cleaner fish. Mirror self-recognition has also been claimed for bottlenose dolphins, using exposure of marked areas to a mirror as evidence. However, what counts as self-directed behaviour to see the mark and what does not has been debated. To avoid this problem, we marked the areas around both eyes of the animals at the same time, one with visible and the other with transparent dye to control for haptic cues. This allowed the animal to see the mark easily and us to investigate what side was exposed to the mirror as an indicator for mark observation. We found that the animals actively chose to inspect their visibly marked side while they did not show an increased interest in a marked conspecific in the pool. These results demonstrate that dolphins use the mirror to inspect their marks and, therefore, likely recognise a distinction between self and others.

Novel products and advertising visuals: the mediating role of perceived luxuriousness on willingness to try clean meat products

Underpinned by art infusion theory and construal level theory, this research examines the role of illustrations and photographs in advertising a novel product (i.e. clean meat) and explores the underlying psychological mechanism of luxuriousness. We conducted three experiments to examine the differential effects of illustrations and photographs on customers’ willingness to try a meat product and ascertain whether this relationship was mediated by perceived luxuriousness. Participants reported a greater willingness to try a novel product, such as clean meat, when the advertisement featured an illustration (vs. a photograph), demonstrating the art infusion effect. However, there were non-significant differences among participants in terms of their willingness to try a familiar product, such as conventional meat. The indirect effect of illustration on willingness to try clean mean via perceived luxuriousness was stronger compared to the conventional meat condition. This mediation effect of luxuriousness was also validated using the moderation-of-process approach. The findings provide meaningful guidelines to marketing practitioners and highlight the pertinence of art infusion to clean meat consumption, a relatively unexplored research area.

The interplay of entrepreneurial ecosystems and global value chains: Insights from the cultivated meat entrepreneurial ecosystem of Singapore

Despite the growing interest in the concept of entrepreneurial ecosystem (EE), the structure of value-adding activities within ecosystems remains overlooked. Therefore, in this paper we explore a possible conceptual interplay between the EE and the global value chain (GVC) literature. We do so by analyzing the case of the cultivated meat (CM) innovation EE of Singapore. Through secondary data and in-depth interviews, it was possible to describe major framework and systemic conditions of the CM Singaporean EE. Such EE conditions were discussed in relation to the evolving cultivated meat chain, in terms of input-output structure, geographic scope, upgrading activity, and chain governance. This, in turn, provided insights that allowed for the conception of a set of seven propositions, which open new avenues for understanding EEs, GVCs, and their interplay in emerging high-tech industries. Moreover, by bringing light to such interplays, our work may contribute to entrepreneurs' and policymakers' activity, so that the transition in the way we produce food contributes to improving social conditions for all.

Food neophobia, food choice and the details of cultured meat acceptance

This study focuses on the details of consumer response to lab grown ‘cultured meat (CM)’, compared to meat derived from insects, plants and animals. A sample of 254 New Zealanders were interviewed. A word association exercise revealed that consumer reaction to CM was dominated by affective, rather than cognitive factors. The linkages between a general food neophobia scale, a specific CM evaluation scale and purchase intent were studied. The general neophobia scale performed poorly as a predictor, while the 19-point CM evaluation scale performed well. Reducing this scale to its seven affective components, and then to just the two key affective components did not significantly reduce the scale's predictive performance. Overall, the results of this research reveal very significant differences in preference for meat products based upon their origins. Insect protein was strongly disfavoured over all alternatives, while cultured meat was significantly disfavoured compared to more established alternatives. The implications of this for the commercialisation of CM are discussed.

Production of scaffold-free cell-based meat using cell sheet technology

In the production of cell-based meat, it is desirable to reduce animal-derived materials as much as possible to meet the challenges of sustainability. Here, we demonstrate the “cell sheet-based meat”: scaffold-free cell-based meat using cell sheet technology and characterize its texture and nutrients. Bovine myoblast cell sheets were prepared using temperature-responsive culture dishes (TRCDs) and 10 stacked cell sheets to fabricate three-dimensional tissue of 1.3–2.7 mm thickness. Hardness was increased by incubation on the TRCD and was further increased by boiling as is characteristic of natural meat. The wet weight percentage of total protein in the cell sheet was about half that of beef. In this method, large-sized items of cell sheet-based meat were also created by simply scaling up the TRCD. This method promises an environment-friendly food product.