Cleaner shrimp as biocontrols in aquaculture
Vaughan, David Brendan (2018) Cleaner shrimp as biocontrols in aquaculture. PhD thesis, James Cook University.
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Abstract
Global aquaculture faces developmental and expansion constraints due to the impacts of diseases. To meet the global demand for protein, aquaculture will need to double by 2050, but a growing concern in aquaculture is the development of drug and chemical resistance by various pathogens, including fish ectoparasites. Of particular concern is the current lack of regulation and surveillance for resistance in the vast majority of aquaculture producing countries, which notably suffer up to 40% production losses due to diseases, at a global combined annual cost exceeding US$6 billion.
Biocontrols such as cleaner fishes have been used successfully in salmonid aquaculture to reduce the impacts of ectoparasitic sea lice, which have traditionally cost this industry millions of US$ annually. This is the only example of exploiting the benefits of a natural cleaning symbiosis for food production. The development of the cleaner fishes biocontrol model was born out of the need to find alternative control measures against the ectoparasitic sea lice which had developed increased levels of resistance to almost all approved commercial drug or chemical applications. The cleaner fishes model is highly successful, and has been developed into its own aquaculture support industry. However, the success of the cleaner fishes model for salmonid aquaculture is restricted geographically, and restricted by the specific feeding preferences of the cleaner fishes to sea lice, and their susceptibility to them.
Tropical and sub-tropical aquaculture experiences a high diversity of economically important fish ectoparasites for which there are no known commercial vaccines, or biocontrols. One of the limiting factors for considering a cleaner fish biocontrol model in tropical and sub-tropical aquaculture is the high probability of susceptibility of cleaner fishes to cosmopolitan ectoparasites with low host-specificity, which infest a large diversity of farmed finfish species. However, the benefits of cleaning symbiosis in a biocontrol model are likely attainable through the use of cleaner shrimp, which are not susceptible to fish ectoparasites.
Initially, cleaning symbiosis required re-evaluation because it represented two separate but similar mutualisms. Cleaning symbiosis was redefined in Chapter 2 to highlight the importance of predisposing communicative behaviour as the catalyst for true symbiotic cleaning interactions, and a comprehensive global list of cleaners and their distribution was provided. This stabilised the foundation on which to explore questions on the truly symbiotic nature of cleaner shrimp, and their specific cleaning abilities at removing different economically important ectoparasites from cultured fishes and from the environment.
In Chapter 3, the cleaner shrimp Lysmata amboinensis was shown unequivocally to tend to injured fish clients in a true cleaning symbiosis, and injury-related inflammation was significantly reduced by the presence of the shrimp. This established the first evidence of wound cleaning of injured fish by cleaner shrimp. The diel ability of L. amboinensis was further tested, together with three other shrimp species, L. vittata, Stenopus hispidus, and Urocaridella antonbruunii against three economically important ectoparasites of cultured fish, Cryptocaryon irritans (ciliate), Neobenedenia girellae (monogenean), and Zeylanicobdella arugamensis (leech) for the first time, in Chapter 4. Although all cleaner shrimp reduced ectoparasites, they did so unequally. Of all the cleaners tested, L. vittata was considered the superior performer for its ability to reduce parasites by up to 97%. Given the potential of the reduction of reinfective stages in aquaculture by this shrimp's performance, L. vittata was selected as the first candidate cleaner shrimp for testing under recirculating aquaculture conditions in Chapter 5 against N. girellae infesting cultured grouper, Epinephelus lanceolatus.
Lysmata vittata, when used as a biocontrol in Chapter 5, significantly reduced the reinfection of N. girellae under recirculating aquaculture conditions by ~87% by consuming the eggs that attach to fish-cage netting. This confirmed the potential of cleaner shrimp to be used to manage ectoparasites in aquaculture. Ectoparasite benthic stages such as eggs, cysts and cocoons are the traditional source of ectoparasite reinfection in aquaculture, and are impervious to drug and chemical treatments. The use of cleaner shrimp may support the reduction of chemical and drug use to treat parasitic outbreaks on fish, but also offers the first real solution to reducing reinfection pressure by consuming traditionally problematic life-stages, thereby reducing infection severity, translating to improved stock health.
Item ID: | 56856 |
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Item Type: | Thesis (PhD) |
Keywords: | aquaculture, biocontrol, cleaner fish, cleaner fishes, cleaner shrimp, cleaning mutualism, cleaning symbioses, cleaning symbiosis, coral reef fishes, ectoparasites injury, Lysamata, Lysmata vittata, parasites, Stenopus, wound healing |
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Copyright Information: | Copyright © 2018 David Brendan Vaughan |
Additional Information: | Publications arising from this thesis are available from the Related URLs field. The publications are: Chapter 2: Vaughan, David Brendan, Grutter, Alexandra Sara, Costello, Mark John, and Hutson, Kate (2017) Cleaner fish and shrimp diversity and a critical evaluation of cleaning symbiosis. Fish and Fisheries, 18 (4). pp. 698-716. Chapter 3: Vaughan, David B., Grutter, Alexandra S., Ferguson, Hugh W., Jones, Rhondda, and Hutson, Kate S. (2018) Cleaner shrimp are true cleaners of injured fish. Marine Biology, 165. Chapter 4: Vaughan, David B., Grutter, Alexandra S., and Hutson, Kate S. (2018) Cleaner shrimp are a sustainable option to treat parasitic disease in farmed fish. Scientific Reports, 8. pp. 1-10. Chapter 5: Vaughan, David B., Grutter, Alexandra S., and Hutson, Kate S. (2018) Cleaner shrimp remove parasite eggs on fish cages. Aquaculture Environment Interactions, 10. pp. 429-436. |
Date Deposited: | 15 Jan 2019 03:56 |
FoR Codes: | 07 AGRICULTURAL AND VETERINARY SCIENCES > 0704 Fisheries Sciences > 070401 Aquaculture @ 50% 07 AGRICULTURAL AND VETERINARY SCIENCES > 0704 Fisheries Sciences > 070404 Fish Pests and Diseases @ 50% |
SEO Codes: | 83 ANIMAL PRODUCTION AND ANIMAL PRIMARY PRODUCTS > 8301 Fisheries - Aquaculture > 830199 Fisheries - Aquaculture not elsewhere classified @ 50% 96 ENVIRONMENT > 9604 Control of Pests, Diseases and Exotic Species > 960407 Control of Pests, Diseases and Exotic Species in Marine Environments @ 50% |
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