1
|
Fjelldal PG, Dalvin S, Ugelvik MS, Pedersen AØ, Hansen TJ, Skjold B, Dyrhovden L, Kroken AK, Karlsen Ø. In sea trout, the physiological response to salmon louse is stronger in female than in males. Conserv Physiol 2023; 11:coac078. [PMID: 36655169 PMCID: PMC9835072 DOI: 10.1093/conphys/coac078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 11/25/2022] [Accepted: 12/06/2022] [Indexed: 06/17/2023]
Abstract
The aims of this study were to compare male and female sea trout (Salmo trutta) with respect to their hypo-osmoregulatory ability over a simulated migration to seawater and their clinical and physiological response to salmon louse (Lepeophtheirus salmonis) infection in seawater and over a simulated pre-mature return to freshwater. For this purpose, 2-year-old hatchery-reared male and female brown trout (F1 offspring of wild caught anadromous fish) were infected with salmon lice and measured for changes in plasma ions, glucose, lactate and osmolality and relative heart, liver and gonad sizes during a simulated seawater migration and thereafter a premature return to freshwater after 4 weeks in seawater (pre-adult louse). Un-infected trout served as control. Male trout used longer time to develop full hypo-osmoregulatory ability in seawater and showed a stronger response in plasma glucose and lactate following simulated premature return to freshwater, compared to female trout. Response to salmon louse was stronger in female trout, shown by stronger osmotic stress by chalimus (plasma Cl-) and pre-adult louse (plasma osmolality) and elevated relative liver size (hepatosomatic index) by pre-adult louse in female compared to male trout. Moreover, high plasma cortisol in infected female and low plasma cortisol in infected male trout produced a significant treatment-sex interaction on plasma cortisol. Lice infection intensity was initially higher in male (0.18 lice g-1) compared to female trout (0.11 lice g-1) at the chalimus stage, but equal between sexes at the pre-adult stage (male 0.15 and female 0.17 lice g-1). This study showed that female trout were better adapted for changes in water salinity, while male trout were more robust against salmon louse infection. These results suggests that the elevated salmon louse infection pressure generated by salmon farming have strong and unexplored negative effects on wild sea trout populations. Further research on this topic is vital for the conservation of wild sea trout populations.
Collapse
Affiliation(s)
- Per Gunnar Fjelldal
- Corresponding author: Institute of Marine Research (IMR), Matre Research Station, Matre 5, 5984 Matredal, Norway. Tel: +47 95 40 24 79.
| | - Sussie Dalvin
- Pathogens and disease transfer, Institute of Marine Research (IMR), PO Box 1870, Nordnes, 5817 Bergen, Norway
| | - Mathias Stølen Ugelvik
- Pathogens and disease transfer, Institute of Marine Research (IMR), PO Box 1870, Nordnes, 5817 Bergen, Norway
| | - Audun Østby Pedersen
- Reproduction and Developmental Biology, Institute of Marine Research (IMR), Matre Research Station, 5984 Matredal, Norway
| | - Tom J Hansen
- Reproduction and Developmental Biology, Institute of Marine Research (IMR), Matre Research Station, 5984 Matredal, Norway
| | - Bjørnar Skjold
- Pathogens and disease transfer, Institute of Marine Research (IMR), PO Box 1870, Nordnes, 5817 Bergen, Norway
| | - Lise Dyrhovden
- Reproduction and Developmental Biology, Institute of Marine Research (IMR), Matre Research Station, 5984 Matredal, Norway
| | - Ann Kathrin Kroken
- Reproduction and Developmental Biology, Institute of Marine Research (IMR), Matre Research Station, 5984 Matredal, Norway
| | - Ørjan Karlsen
- Reproduction and Developmental Biology, Institute of Marine Research (IMR), PO Box 1870, Nordnes, 5817 Bergen, Norway
| |
Collapse
|
2
|
Delfosse C, Pageat P, Lafont‐Lecuelle C, Asproni P, Chabaud C, Cozzi A, Bienboire‐Frosini C. Effect of handling and crowding on the susceptibility of Atlantic salmon (Salmo salar L.) to Lepeophtheirus salmonis (Krøyer) copepodids. J Fish Dis 2021; 44:327-336. [PMID: 33112458 PMCID: PMC7894147 DOI: 10.1111/jfd.13286] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 09/26/2020] [Accepted: 09/29/2020] [Indexed: 05/08/2023]
Abstract
Lepeophtheirus salmonis is an ectoparasite causing economic concerns in Atlantic salmon farming. Salmon lice infestation management methods can be stressful and impact fish welfare. This work investigated the stress effect on the attachment of L. salmonis copepodids to Atlantic salmon through two approaches: (a) handling by netting and air exposure (acute stress), and (b) crowding with restricted surface access in a tank (chronic stress). In the first experiment, we compared the number of attached L. salmonis and cortisol levels between a group of handled salmon and a control group. In the second experiment, a group of densely packed salmon was compared to a control group based on the number of attached copepodids, cortisol levels and neutrophil:lymphocyte ratios. Handled salmon showed significantly higher plasma cortisol levels (p < .001) and more attached copepodids (p = .01) than control salmon. Conversely, the cortisol level and number of attached copepodids were not significantly different between the densely packed and control salmon (p > .05). The neutrophil:lymphocyte ratio was significantly higher (p = .0014) in the densely packed salmon than in the control salmon. Handling salmon increased their risk of infestation by L. salmonis. This has implications for reinfestation rates following delousing treatments in commercial salmon aquaculture, which often involve crowding and handling salmon.
Collapse
Affiliation(s)
- Cyril Delfosse
- Research Institute in Semiochemistry and Applied Ethology (IRSEA)AptFrance
- IRSEA‐ARCDaugstadNorway
| | - Patrick Pageat
- Research Institute in Semiochemistry and Applied Ethology (IRSEA)AptFrance
- IRSEA‐ARCDaugstadNorway
| | | | - Pietro Asproni
- Research Institute in Semiochemistry and Applied Ethology (IRSEA)AptFrance
| | - Camille Chabaud
- Research Institute in Semiochemistry and Applied Ethology (IRSEA)AptFrance
- IRSEA‐ARCDaugstadNorway
| | - Alessandro Cozzi
- Research Institute in Semiochemistry and Applied Ethology (IRSEA)AptFrance
- IRSEA‐ARCDaugstadNorway
| | | |
Collapse
|
3
|
Fjelldal PG, Hansen TJ, Karlsen Ø. Effects of laboratory salmon louse infection on osmoregulation, growth and survival in Atlantic salmon. Conserv Physiol 2020; 8:coaa023. [PMID: 32257215 PMCID: PMC7098368 DOI: 10.1093/conphys/coaa023] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 02/11/2020] [Accepted: 03/02/2020] [Indexed: 06/02/2023]
Abstract
Anadromous Atlantic salmon (Salmo salar) rely on long ocean migrations to build energy stores for maturation and spawning. In seawater, wild Atlantic salmon are threatened by high salmon lice (Lepeophtheirus salmonis) infestation levels resulting from intensive salmonid sea-cage aquaculture. Salmon lice infection can cause a stress response and an osmotic imbalance in the host. The lice infection intensity threshold values for these responses, however, remain to be identified in Atlantic salmon. In order to define this under laboratory conditions, individually tagged F1 wild origin Atlantic post-smolts (40 g) were infected with salmon lice copepodids or left as uninfected controls. Twenty-eight days post infection, infected post-smolts had a mean of 0.38 (range of 0.07-0.9) mobile lice g-1 fish weight. During this period, specific growth rates (SGRs) were lower in infected than control fish (0.4 vs 1.0% day-1). Higher plasma Na+, Cl- and osmolality in infected fish also indicate osmoregulatory impairment. SGR correlated negatively with plasma Na+, Cl-, osmolality and cortisol in the infected, but not in the control group. Infection intensity (lice g-1 fish) correlated positively with mortality rate and plasma Na+, Cl-, osmolality and cortisol and correlated negatively with SGR and condition factor. Calculated lice intensity threshold values for changes in plasma ions were 0.18 lice g-1 for plasma Cl-, and 0.22 lice g-1 for plasma Na+. Moribund infected fish occurred at infection intensities above 0.2 lice g-1, and these fish had extreme plasma Cl-, Na+, osmolality and cortisol levels. There was a positive correlation between plasma cortisol and plasma Na+, Cl- and osmolality in infected fish. This study provides vital information that can be used to define thresholds in the monitoring and conservation of wild Atlantic salmon populations affected by aquaculture-driven salmon lice infestations.
Collapse
Affiliation(s)
- Per Gunnar Fjelldal
- Reproduction and Developmental Biology, Institute of Marine Research (IMR), Matre Aquaculture Research Station, 5984 Matredal, Norway
| | - Tom J Hansen
- Reproduction and Developmental Biology, Institute of Marine Research (IMR), Matre Aquaculture Research Station, 5984 Matredal, Norway
| | - Ørjan Karlsen
- Reproduction and Developmental Biology, Institute of Marine Research (IMR), PO Box 1870, Nordnes, 5817 Bergen, Norway
| |
Collapse
|
4
|
Contreras M, Karlsen M, Villar M, Olsen RH, Leknes LM, Furevik A, Yttredal KL, Tartor H, Grove S, Alberdi P, Brudeseth B, de la Fuente J. Vaccination with Ectoparasite Proteins Involved in Midgut Function and Blood Digestion Reduces Salmon Louse Infestations. Vaccines (Basel) 2020; 8:vaccines8010032. [PMID: 31963779 PMCID: PMC7157638 DOI: 10.3390/vaccines8010032] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 01/16/2020] [Accepted: 01/17/2020] [Indexed: 11/16/2022] Open
Abstract
Infestation with the salmon louse Lepeophtheirus salmonis (Copepoda, Caligidae) affects Atlantic salmon (Salmo salar L.) production in European aquaculture. Furthermore, high levels of salmon lice in farms significantly increase challenge pressure against wild salmon populations. Currently, available control methods for salmon louse have limitations, and vaccination appears as an attractive, environmentally sound strategy. In this study, we addressed one of the main limitations for vaccine development, the identification of candidate protective antigens. Based on recent advances in tick vaccine research, herein, we targeted the salmon louse midgut function and blood digestion for the identification of candidate target proteins for the control of ectoparasite infestations. The results of this translational approach resulted in the identification and subsequent evaluation of the new candidate protective antigens, putative Toll-like receptor 6 (P30), and potassium chloride, and amino acid transporter (P33). Vaccination with these antigens provided protection in Atlantic salmon by reducing adult female (P33) or chalimus II (P30) sea lice infestations. These results support the development of vaccines for the control of sea lice infestations.
Collapse
Affiliation(s)
- Marinela Contreras
- SaBio, Instituto de Investigación en Recursos Cinegéticos IREC-CSIC-UCLM-JCCM, Ronda de Toledo s/n, 13005 Ciudad Real, Spain; (M.C.); (M.V.); (P.A.)
| | - Marius Karlsen
- Pharmaq AS, P.O. Box 267, Skoyen, N-0213 Oslo, Norway; (M.K.); (R.H.O.); (L.M.L.); (A.F.); (K.L.Y.)
| | - Margarita Villar
- SaBio, Instituto de Investigación en Recursos Cinegéticos IREC-CSIC-UCLM-JCCM, Ronda de Toledo s/n, 13005 Ciudad Real, Spain; (M.C.); (M.V.); (P.A.)
- Biochemistry Section, Faculty of Science and Chemical Technologies, and Regional Centre for Biomedical Research (CRIB), University of Castilla-La Mancha, 13071 Ciudad Real, Spain
| | - Rolf Hetlelid Olsen
- Pharmaq AS, P.O. Box 267, Skoyen, N-0213 Oslo, Norway; (M.K.); (R.H.O.); (L.M.L.); (A.F.); (K.L.Y.)
| | - Lisa Marie Leknes
- Pharmaq AS, P.O. Box 267, Skoyen, N-0213 Oslo, Norway; (M.K.); (R.H.O.); (L.M.L.); (A.F.); (K.L.Y.)
| | - Anette Furevik
- Pharmaq AS, P.O. Box 267, Skoyen, N-0213 Oslo, Norway; (M.K.); (R.H.O.); (L.M.L.); (A.F.); (K.L.Y.)
| | - Karine Lindmo Yttredal
- Pharmaq AS, P.O. Box 267, Skoyen, N-0213 Oslo, Norway; (M.K.); (R.H.O.); (L.M.L.); (A.F.); (K.L.Y.)
| | - Haitham Tartor
- Norwegian Veterinary Institute, 0106 Oslo, Norway; (H.T.); (S.G.)
| | - Soren Grove
- Norwegian Veterinary Institute, 0106 Oslo, Norway; (H.T.); (S.G.)
- Institute of Marine Research, 5005 Bergen, Norway
| | - Pilar Alberdi
- SaBio, Instituto de Investigación en Recursos Cinegéticos IREC-CSIC-UCLM-JCCM, Ronda de Toledo s/n, 13005 Ciudad Real, Spain; (M.C.); (M.V.); (P.A.)
| | - Bjorn Brudeseth
- Pharmaq AS, P.O. Box 267, Skoyen, N-0213 Oslo, Norway; (M.K.); (R.H.O.); (L.M.L.); (A.F.); (K.L.Y.)
- Correspondence: (B.B.); (J.d.l.F.)
| | - José de la Fuente
- SaBio, Instituto de Investigación en Recursos Cinegéticos IREC-CSIC-UCLM-JCCM, Ronda de Toledo s/n, 13005 Ciudad Real, Spain; (M.C.); (M.V.); (P.A.)
- Department of Veterinary Pathobiology, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK 74078, USA
- Correspondence: (B.B.); (J.d.l.F.)
| |
Collapse
|
5
|
Stavang JA, Chauvigné F, Kongshaug H, Cerdà J, Nilsen F, Finn RN. Phylogenomic and functional analyses of salmon lice aquaporins uncover the molecular diversity of the superfamily in Arthropoda. BMC Genomics 2015; 16:618. [PMID: 26282991 PMCID: PMC4539701 DOI: 10.1186/s12864-015-1814-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 08/03/2015] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND An emerging field in biomedical research is focusing on the roles of aquaporin water channels in parasites that cause debilitating or lethal diseases to their vertebrate hosts. The primary vectorial agents are hematophagous arthropods, including mosquitoes, flies, ticks and lice, however very little is known concerning the functional diversity of aquaporins in non-insect members of the Arthropoda. Here we conducted phylogenomic and functional analyses of aquaporins in the salmon louse, a marine ectoparasitic copepod that feeds on the skin and body fluids of salmonids, and used the primary structures of the isolated channels to uncover the genomic repertoires in Arthropoda. RESULTS Genomic screening identified 7 aquaporin paralogs in the louse in contrast to 42 in its host the Atlantic salmon. Phylogenetic inference of the louse nucleotides and proteins in relation to orthologs identified in Chelicerata, Myriapoda, Crustacea and Hexapoda revealed that the arthropod aquaporin superfamily can be classified into three major grades (1) classical aquaporins including Big brain (Bib) and Prip-like (PripL) channels (2) aquaglyceroporins (Glp) and (3) unorthodox aquaporins (Aqp12-like). In Hexapoda, two additional subfamilies exist as Drip and a recently classified entomoglyceroporin (Eglp) group. Cloning and remapping the louse cDNAs to the genomic DNA revealed that they are encoded by 1-7 exons, with two of the Glps being expressed as N-terminal splice variants (Glp1_v1, -1_v2, -3_v1, -3_v2). Heterologous expression of the cRNAs in amphibian oocytes demonstrated that PripL transports water and urea, while Bib does not. Glp1_v1, -2, -3_v1 and -3_v2 each transport water, glycerol and urea, while Glp1_v2 and the Aqp12-like channels were retained intracellularly. Transcript abundance analyses revealed expression of each louse paralog at all developmental stages, except for glp1_v1, which is specific to preadult and adult males. CONCLUSIONS Our data suggest that the aquaporin repertoires of extant arthropods have expanded independently in the different lineages, but can be phylogenetically classified into three major grades as opposed to four present in deuterostome animals. While the aquaporin repertoire of Atlantic salmon represents a 6-fold redundancy compared to the louse, the functional assays reveal that the permeation properties of the different crustacean grades of aquaporin are largely conserved to the vertebrate counterparts.
Collapse
Affiliation(s)
- Jon Anders Stavang
- Sea Lice Research Centre, Department of Biology, Bergen High Technology Centre, University of Bergen, 5020, Bergen, Norway.
| | - Francois Chauvigné
- Sea Lice Research Centre, Department of Biology, Bergen High Technology Centre, University of Bergen, 5020, Bergen, Norway.
- Institut de Recerca i Tecnologia Agroalimentàries (IRTA)-Institut de Ciències del Mar, Consejo Superior de Investigaciones Científicas (CSIC), 08003, Barcelona, Spain.
| | - Heidi Kongshaug
- Sea Lice Research Centre, Department of Biology, Bergen High Technology Centre, University of Bergen, 5020, Bergen, Norway.
| | - Joan Cerdà
- Institut de Recerca i Tecnologia Agroalimentàries (IRTA)-Institut de Ciències del Mar, Consejo Superior de Investigaciones Científicas (CSIC), 08003, Barcelona, Spain.
| | - Frank Nilsen
- Sea Lice Research Centre, Department of Biology, Bergen High Technology Centre, University of Bergen, 5020, Bergen, Norway.
| | - Roderick Nigel Finn
- Sea Lice Research Centre, Department of Biology, Bergen High Technology Centre, University of Bergen, 5020, Bergen, Norway.
- Institute of Marine Research, Nordnes, 5817, Bergen, Norway.
| |
Collapse
|
6
|
Grave K, Engelstad M, Søli NE. Utilization of dichlorvos and trichlorfon in salmonid farming in Norway during 1981-1988. Acta Vet Scand 1991; 32:1-7. [PMID: 1950842 PMCID: PMC8127918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The main objectives of this investigation were to quantify the use of dichlorvos and trichlorfon in the treatment of salmon lice infestations, to evaluate the prescribing of these drugs, and to estimate possible changes in the salmon lice problem by use of drug statistics. This study has shown that the use of trichlorfon increased from 4.9 tons in 1981 to 28.3 tons in 1985. This figure declined to 3.2 tons in 1988. The use of dichlorvos increased from 0.3 tons in 1986 to 3.2 tons in 1988. The change in the prescribing from trichlorfon to dichlorvos has dramatically reduced the pollution caused by these substances in the marine environment. Moreover, if necessary safety rules are observed, this change reduces the exposure of the workers on fish farms to these drugs, and also reduces the possibilities of intoxications of the fish during the treatment procedure. The sales figures of dichlorvos and trichlorfon, related to the calculated biomass of farmed salmonids in the sea, indicate a dramatic increase in the salmon lice problem.
Collapse
Affiliation(s)
- K Grave
- Department of Pharmacology and Toxicology, Norwegian College of Veterinary Medicine, Oslo
| | | | | |
Collapse
|