1
|
Hasegawa R, Koizumi I. Consistent Negative Correlations between Parasite Infection and Host Body Condition Across Seasons Suggest Potential Harmful Impacts of Salmincola markewitschi on Wild White-Spotted Charr, Salvelinus leucomaenis. Zoolog Sci 2024; 41:192-200. [PMID: 38587914 DOI: 10.2108/zs230028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 10/23/2023] [Indexed: 04/10/2024]
Abstract
Assessing the impacts of parasites on wild fish populations is a fundamental and challenging aspect of the study of host-parasite relationships. Salmincola, a genus of ectoparasitic copepods, mainly infects salmonid species. This genus, which is notorious in aquaculture, damages host fishes, but its impacts under natural conditions remain largely unknown or are often considered negligible. In this study, we investigated the potential impacts of mouth-attaching Salmincola markewitschi on white-spotted charr (Salvelinus leucomaenis) through intensive field surveys across four seasons using host body condition as an indicator of harmful effects. The prevalence and parasite abundance were highest in winter and gradually decreased in summer and autumn, which might be due to host breeding and/or wintering aggregations that help parasite transmissions. Despite seasonal differences in prevalence and parasite abundance, consistent negative correlations between parasite abundance and host body condition were observed across all seasons, indicating that the mouth-attaching copepods could reduce the body condition of the host fish. This provides field evidence suggesting that S. markewitschi has a potential negative impact on wild white-spotted charr.
Collapse
Affiliation(s)
- Ryota Hasegawa
- Graduate School of Environmental Science, Hokkaido University, Hokkaido 060-0810, Japan,
| | - Itsuro Koizumi
- Graduate School of Environmental Science, Hokkaido University, Hokkaido 060-0810, Japan
- Faculty of Environmental Earth Science, Hokkaido University, Hokkaido 060-0810, Japan
| |
Collapse
|
2
|
Herron CL, Ruse NE, Rockey DD, Sanders JL, Peterson JT, Schreck CB, Kent ML. Aeromonas salmonicida, causative agent of salmonid furunculosis, isolated from the freshwater parasitic copepod, Salmincola californiensis. JOURNAL OF FISH DISEASES 2024; 47:e13885. [PMID: 37947250 DOI: 10.1111/jfd.13885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 10/23/2023] [Accepted: 10/27/2023] [Indexed: 11/12/2023]
Abstract
Here, we provide evidence that the freshwater parasitic copepod, Salmincola californiensis, acts as a vector for Aeromonas salmonicida. While investigating the effects of S. californiensis on Chinoook salmon (Oncorhynchus tshawytscha), we tangentially observed that fish infected with the copepod developed furunculosis, caused by A. salmonicida. This occurred despite being reared in pathogen-free well water in a research facility with no prior history of spontaneous infection. We further investigated the possibility of S. californiensis to serve as a vector for the bacterium via detection of fluorescently labelled A. salmonicida inside the egg sacs from copepods in which the fish hosts were experimentally infected with GFP-A449 A. salmonicida. We then evaluated copepod egg sacs that were collected from adult Chinook salmon from a freshwater hatchery with A. salmonicida infections confirmed by either culture or PCR. The bacterium was cultured on tryptic soy agar plates from 75% of the egg sacs, and 61% were positive by PCR. These three separate experiments indicate an alternative tactic of transmission in addition to direct transmission of A. salmonicida in captivity. The copepod may play an important role in transmission of the bacterium when fish are more dispersed, such as in the wild.
Collapse
Affiliation(s)
- Crystal L Herron
- Department of Fisheries, Wildlife, and Conservation Sciences, Oregon State University, Corvallis, Oregon, USA
| | - Natassia E Ruse
- Carlson College of Veterinary Medicine, Oregon State University, Corvallis, Oregon, USA
- Department of Biomedical Sciences, Oregon State University, Corvallis, Oregon, USA
- VCA Rock Creek Animal Hospital, Aloha, Oregon, USA
| | - Daniel D Rockey
- Department of Biomedical Sciences, Oregon State University, Corvallis, Oregon, USA
| | - Justin L Sanders
- Department of Biomedical Sciences, Oregon State University, Corvallis, Oregon, USA
| | - James T Peterson
- Department of Fisheries, Wildlife, and Conservation Sciences, Oregon State University, Corvallis, Oregon, USA
- U.S. Geological Survey, Oregon Cooperative Fish and Wildlife Research Unit, Corvallis, Oregon, USA
| | - Carl B Schreck
- Department of Fisheries, Wildlife, and Conservation Sciences, Oregon State University, Corvallis, Oregon, USA
| | - Michael L Kent
- Department of Microbiology, Oregon State University, Corvallis, Oregon, USA
| |
Collapse
|
3
|
Murphy CA, Gerth W, Neal T, Antonelli K, Sanders JL, Williams T, Roennfeldt RL, Crowhurst RS, Arismendi I. Evidence for infection influencing survival of the freshwater copepod Salmincola californiensis, a parasite of Pacific salmon and trout. JOURNAL OF AQUATIC ANIMAL HEALTH 2023; 35:280-285. [PMID: 37872816 DOI: 10.1002/aah.10206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 08/25/2023] [Accepted: 09/18/2023] [Indexed: 10/25/2023]
Abstract
OBJECTIVE We explore apparent infection of Salmincola californiensis arising during investigations involving this lernaeopodid copepod parasitic on Pacific salmon and trout Oncorhynchus spp. METHODS We noted occasional unusual coloration of adult female copepods collected from the wild. These females were bright blue and pink in contrast to the cream white coloration characteristic of the copepod. We also observed that similar color patterns developed under laboratory settings when copepod eggs were held for hatching. In paired egg cases, we found consistent hatching failure of blue and pink eggs and patterns in apparent disease development that would be consistent with both vertical and horizontal transmission. RESULT Attempts to identify the cause of the apparent infection using genetic methods and transmission electron microscopy were inconclusive. CONCLUSION Iridovirus infection was initially suspected, but bacterial infection is also plausible. This apparent reduced hatching success of S. californiensis warrants further exploration as it could reduce local abundances. Given the potential importance of a disease impacting this copepod, a parasite that itself affects endangered and commercially important Pacific salmon and trout, future research would benefit from clarification of the apparent infection through additional sequencing, primer development, visualization, and exploration into specificity and transmission.
Collapse
Affiliation(s)
- Christina A Murphy
- U.S. Geological Survey, Maine Cooperative Fish and Wildlife Research Unit, Orono, Maine, USA
- Department of Wildlife, Fisheries, and Conservation Biology, University of Maine, Orono, Maine, USA
- Department of Fisheries, Wildlife, and Conservation Sciences, Oregon State University, Oregon, USA
| | - William Gerth
- Department of Fisheries, Wildlife, and Conservation Sciences, Oregon State University, Oregon, USA
| | - Travis Neal
- Department of Fisheries, Wildlife, and Conservation Sciences, Oregon State University, Oregon, USA
| | - Kelsi Antonelli
- Department of Fisheries, Wildlife, and Conservation Sciences, Oregon State University, Oregon, USA
| | - Justin L Sanders
- Department of Biomedical Sciences, Oregon State University, Oregon, USA
| | | | - Ruben-Lee Roennfeldt
- Centre for Sustainable Aquatic Ecosystems, Harry Butler Institute, Murdoch University, Murdoch, Western Australia, Australia
| | - Rachel S Crowhurst
- Department of Fisheries, Wildlife, and Conservation Sciences, Oregon State University, Oregon, USA
| | - Ivan Arismendi
- Department of Fisheries, Wildlife, and Conservation Sciences, Oregon State University, Oregon, USA
| |
Collapse
|
4
|
Nagasawa K. Live Freshwater Parasite, Salmincola californiensis (Copepoda: Lernaeopodidae), on the Gills of an Ocean-Migrating Steelhead Trout ( Oncorhynchus mykiss) and Discussion on the Origin and Survival of the Parasite at Sea. Zoolog Sci 2023; 40:360-366. [PMID: 37818884 DOI: 10.2108/zs230031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2023] [Accepted: 06/23/2023] [Indexed: 10/13/2023]
Abstract
Salmincola californiensis is a parasitic copepod of freshwater salmonids in the North Pacific rim countries. Sixteen adult females of the species were found alive on the gills of an ocean-age 4, maturing steelhead trout, Oncorhynchus mykiss, caught in offshore waters (50°30'N, 179°30'W) of the North Pacific Ocean in July 1997. This is the first evidence of live individuals of S. californiensis from ocean-migrating salmonids. When found, copepods were attached to the distal ends of gill filaments, and their bodies were observed to be slowly moving in Petri dishes with seawater. Ocean-migrating steelhead trout comprise individuals originating from western Kamchatka (Russia) and western North America. Based on the date and catch location of the infected fish, it is inferred that it originated from western North America, where it acquired S. californiensis infection in fresh water. As this fish spent about 4 years in the ocean, the copepods likely survived the same period at sea. However, if the fish was a kelt, the survival period of the copepods in the ocean may be shorter than four years. To confirm identification of the copepods, adult females of S. californiensis are briefly described using the specimens collected from the fish.
Collapse
Affiliation(s)
- Kazuya Nagasawa
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8528, Japan,
| |
Collapse
|
5
|
Murphy CA, Gerth W, Neal T, Arismendi I. A low-cost, durable, submersible light trap and customisable LED design for pelagic deployment and capture of fish parasite Salmincola sp. copepodids. NEOBIOTA 2022. [DOI: 10.3897/neobiota.73.76515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Documenting species invasions and assessments of ecological changes depend on detection. Here, we present a simple design of a plankton light trap with specific wavelength LEDs and modifications. We used PVC pipe to create standardised small, rigid, low-cost traps that can be deployed in lentic habitats. With a cost of under $30 US each, including lights and rechargeable batteries, our traps are affordable without the need for disposable chemical lights. These small traps rely on a vacuum to retain contents upon retrieval, eliminating complicated closing mechanisms and allowing bottom entry. Our design includes submersible LED lights that can withstand pressures of at least 5 atm. We expect that the included instructions for underwater light construction and rubber weights using sand may be broadly applicable. However, we designed and field-tested our traps focusing on the detection and capture of the infective copepodid lifestage of a freshwater parasitic copepod, Salmincola californiensis. This lifestage had previously only been observed by rearing in a laboratory setting and is of concern due to continued spread outside of its native range and detrimental impacts on salmonids, especially in freshwater reservoirs. We used a 445–450 nm wavelength LED light for capturing Salmincola copepodids, but the light design can be modified to any readily available LED and heat sink to attract other target organisms. In our case, the overall affordability of the trap and components allowed for the extensive trapping needed to capture and map the occurrence of rarely-observed species and lifestages, such as the copepodids of S. californiensis. In general, increasing the number of traps that can be deployed within or across sites can aid in the spatial comparisons of plankton distributions needed in studies of ecology and species life histories. Light traps may aid in the detection of introduced zooplankton, such as S. californiensis, outside of their native range and associated plankton community changes.
Collapse
|
6
|
Lepak JM, Hansen AG, Hooten MB, Brauch D, Vigil EM. Rapid proliferation of the parasitic copepod, Salmincola californiensis (Dana), on kokanee salmon, Oncorhynchus nerka (Walbaum), in a large Colorado reservoir. JOURNAL OF FISH DISEASES 2022; 45:89-98. [PMID: 34585403 DOI: 10.1111/jfd.13539] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 09/05/2021] [Accepted: 09/08/2021] [Indexed: 06/13/2023]
Abstract
Ecologically and economically valuable Pacific salmon and trout (Oncorhynchus spp.) are widespread and susceptible to the ectoparasite Salmincola californiensis (Dana). The range of this freshwater copepod has expanded, and in 2015, S. californiensis was observed in Blue Mesa Reservoir, Colorado, USA, an important kokanee salmon (O. nerka, Walbaum) egg source for sustaining fisheries. Few S. californiensis were detected on kokanee salmon in 2016 (<10% prevalence; 2 adult S. californiensis maximum). By 2020, age-3 kokanee salmon had 100% S. californiensis prevalence and mean intensity exceeding 50 adult copepods. Year and kokanee salmon age/maturity (older/mature) were consistently identified as significant predictors of S. californiensis prevalence/intensity. There was evidence that S. californiensis spread rapidly, but their population growth was maximized at the initiation (the first 2-3 years) of the invasion. Gills and heads of kokanee salmon carried the highest S. californiensis loads. S. californiensis population growth appears to be slowing, but S. californiensis expansion occurred concomitant with myriad environmental/biological factors. These factors and inherent variance in S. californiensis count data may have obscured patterns that continued monitoring of parasite-host dynamics, when S. californiensis abundance is more stable, might reveal. The rapid proliferation of S. californiensis indicates that in 5 years a system can go from a light infestation to supporting hosts carrying hundreds of parasites, and concern remains about the sustainability of this kokanee salmon population.
Collapse
Affiliation(s)
- Jesse M Lepak
- Colorado Parks and Wildlife, Aquatic Research Section, Fort Collins, Colorado, USA
| | - Adam G Hansen
- Colorado Parks and Wildlife, Aquatic Research Section, Fort Collins, Colorado, USA
| | - Mevin B Hooten
- Department of Statistics and Data Sciences, The University of Texas at Austin, Austin, Texas, USA
| | - Daniel Brauch
- Colorado Parks and Wildlife, Gunnison, Colorado, USA
| | | |
Collapse
|
7
|
Hasegawa R, Ayer CG, Umatani Y, Miura K, Ukumura M, Katahira H, Koizumi I. Potential negative effects and heterogeneous distribution of a parasitic copepod Salmincola edwardsii (Copepoda: Lernaeopodidae) on Southern Asian Dolly Varden Salvelinus curilus in Hokkaido, Japan. Parasitol Int 2021; 87:102529. [PMID: 34896616 DOI: 10.1016/j.parint.2021.102529] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 08/19/2021] [Accepted: 12/06/2021] [Indexed: 11/25/2022]
Abstract
The genus Salmincola is an ectoparasitic copepod group commonly infesting the branchial and buccal cavities of salmonids. While negative impacts on hatchery fishes have been reported, their impacts on wild fish populations and distribution patterns are critically understudied. In the Shiretoko Peninsula, Hokkaido, Japan, we found parasites belonging to this genus on the branchial cavity of a stream salmonid, Southern Asian Dolly Varden Salvelinus curilus. All parasites recovered were identified as Salmincola edwardsii based on morphological characteristics and partial 28S rDNA sequences. Prevalence was highly heterogeneous even among neighboring streams (0-54.8%, < 10 km) with the mean intensity among streams being generally low (2.19 parasites/infeted fish). Despite the low intensity, quantile regression analysis showed negative trends between parasite intensity and host condition, suggesting that the infestation of S. edwardsii has a potential negative impact on the host salmonid. In addition, a single copepod was found from an anadromous fish, which could indicate some salinity tolerance of the copepods. It is important to evaluate the effects of Salmincola spp. on host species and determine the limiting factors on the parasite's distribution for proper management.
Collapse
Affiliation(s)
- Ryota Hasegawa
- Graduate School of Environmental Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan.
| | - Christopher G Ayer
- Graduate School of Environmental Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan
| | - Yoshiyuki Umatani
- Field Science Center for Northern Biosphere, Hokkaido University, Sapporo, Hokkaido 060-0809, Japan
| | - Kazuki Miura
- Shiretoko Museum, Honmachi 49, Shari, Shari-gun, Hokkaido 099-4113, Japan
| | - Miyo Ukumura
- Sapporo Wild Salmon Project, 2-1 Makomanai Park, Minami-ku, Sapporo, Hokkaido 005-0017, Japan
| | - Hirotaka Katahira
- Department of Environmental Science, School of Life and Environmental Science, Azabu University, 1-17-71 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5201, Japan
| | - Itsuro Koizumi
- Graduate School of Environmental Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan; Faculty of Environmental Earth Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan
| |
Collapse
|
8
|
Suchomel AD, Billman EJ. Prevalence and Intensity of Infection of the Parasitic Copepod Salmincola californiensis on Rainbow Trout in Birch Creek, Idaho. WEST N AM NATURALIST 2021. [DOI: 10.3398/064.081.0413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
| | - Eric J. Billman
- Department of Biology, Brigham Young University–Idaho, Rexburg, ID
| |
Collapse
|
9
|
Hasegawa R, Koizumi I. Relative importance of host‐dependent versus physical environmental characteristics affecting the distribution of an ectoparasitic copepod infecting the mouth cavity of stream salmonid. Ecol Res 2021. [DOI: 10.1111/1440-1703.12262] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ryota Hasegawa
- Graduate School of Environmental Science Hokkaido University Sapporo Japan
| | - Itsuro Koizumi
- Graduate School of Environmental Science Hokkaido University Sapporo Japan
- Faculty of Environmental Earth Science Hokkaido University Sapporo Japan
| |
Collapse
|
10
|
Neal T, Kent ML, Sanders J, Schreck CB, Peterson JT. Laboratory infection rates and associated mortality of juvenile Chinook Salmon (Oncorhynchus tshawytscha) from parasitic copepod (Salmincola californiensis). JOURNAL OF FISH DISEASES 2021; 44:1423-1434. [PMID: 34053103 DOI: 10.1111/jfd.13450] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 05/04/2021] [Accepted: 05/06/2021] [Indexed: 06/12/2023]
Abstract
Pacific salmon (Oncorhynchus spp.) rearing in lakes and reservoirs above dams have been known to become heavily infected with an ectoparasitic copepod (Salmincola californiensis). Little is known about the factors that affect the parasite infection prevalence and intensity. However, previous research suggests that the parasite may negatively affect the fitness and survival of the host fish. The effect of water temperature, confinement and the density of the free-swimming infectious stage of S. californiensis, the copepodid, on infection prevalence and intensity was evaluated by experimentally exposing juvenile Chinook Salmon (O. tshawytscha). Infection rates observed in wild populations were achieved under warm water (15-16°C) and high copepodid density (150-300/L) treatment conditions. Infection prevalence and intensity were also significantly higher in larger fish. During the infection experiment, 4.5% of infected fish died within 54 days with mortality significantly related to copepod infection intensity. The potential for autoinfection was compared to cross-infection by cohabitation of infected fish with naïve fish. Previously infected fish had significantly greater infection intensity compared with naïve fish, indicating that infected fish can be reinfected and that they may be more susceptible than naïve fish.
Collapse
Affiliation(s)
- Travis Neal
- Department of Fisheries and Wildlife, Oregon State University, Corvallis, OR, USA
| | - Michael L Kent
- Department of Microbiology, Oregon State University, Corvallis, OR, USA
- Department of Biomedical Sciences, Oregon State University, Corvallis, OR, USA
| | - Justin Sanders
- Department of Biomedical Sciences, Oregon State University, Corvallis, OR, USA
| | - Carl B Schreck
- Department of Fisheries and Wildlife, Oregon State University, Corvallis, OR, USA
| | - James T Peterson
- US Geological Survey, Oregon Cooperative Fish and Wildlife Research Unit, Department of Fisheries and Wildlife, Oregon State University, Corvallis, OR, USA
| |
Collapse
|
11
|
Hatching and survival of the salmon 'gill maggot' Salmincola californiensis (Copepoda: Lernaeopodidae) reveals thermal dependence and undocumented naupliar stage. Parasitology 2020; 147:1338-1343. [PMID: 32660654 DOI: 10.1017/s0031182020001109] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Salmincola californiensis is a Lernaeopodid copepod parasitizing Pacific salmon and trout of the genus Oncorhynchus. Salmincola californiensis is of increasing concern in both native and introduced ranges because of its potential fish health impacts and high infection prevalence and intensity in some systems. Discrepancies in the documented life history phenology of S. californiensis with the sister species Salmincola edwardsii, as well as our laboratory observations, led us to question the existing literature. We documented a naupliar stage, thought lost for S. californiensis. In addition, we found a high degree of thermal sensitivity in egg development, with eggs developing faster under warmer conditions. Survival of copepodids was also highly dependent on temperature, with warmer conditions reducing lifespan. The longest lived copepodid survived 18 days at 4°C in stark contrast to the generally accepted <48 h survival for that life stage. We also note a consistent relationship between egg sac size and the number of eggs contained. However, egg sac sizes were highly variable. Our findings demonstrate that revisiting old assumptions for S. californiensis and related taxa will be a necessary step to improving our knowledge of the parasite life history and development that will be critical to disease management.
Collapse
|
12
|
White CFH, Gray MA, Kidd KA, Duffy MS, Lento J, Monk WA. Prevalence and Intensity of Salmincola edwardsii in Brook Trout in Northwest New Brunswick, Canada. JOURNAL OF AQUATIC ANIMAL HEALTH 2020; 32:11-20. [PMID: 31965614 DOI: 10.1002/aah.10091] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 09/17/2019] [Indexed: 06/10/2023]
Abstract
Parasites can compromise the health and fitness of individual fish, and it is important to generate baseline information that can then be used to document changes in the abundance and distribution of potentially pathogenic parasites. The ectoparasitic copepod Salmincola edwardsii was assessed with respect to prevalence (percentage of infected fish per site), infection intensity (number of parasites per infected fish), and attachment location on Brook Trout Salvelinus fontinalis in northwest New Brunswick, Canada. Ten sample sites were assessed, with six sites on two streams in the Quisibis River basin and four sites on three streams in the Restigouche River basin. Parasite species identity was supported by 100% sequence identity with S. edwardsii in a variable region within 28S rDNA. The prevalence of fish infected per site ranged from 19.0% to 79.6%, with an overall prevalence of 48.5 ± 19.1% (mean ± SD) per site. Mean infection intensity was 1.5 ± 0.9 copepods/fish (range = 1-7), with parasites almost exclusively surrounding the dorsal fin and/or adipose fin (97.6%). There was no influence of trout age-class on parasite prevalence. Some fish presented with fin erosion at the site of parasite attachment (12.5%), and 6.2% also presented with hyperplastic skin lesions where no parasites were observed, that could be misinterpreted as secondary bacterial or fungal infections. Skin and fin damage were significantly more common when fish were infected with three or more individual parasites. The pathogenic potential of this parasite makes its presence noteworthy as a risk to salmonids that are both recreationally and ecologically important.
Collapse
Affiliation(s)
- Carson F H White
- Canadian Rivers Institute, University of New Brunswick, Fredericton, New Brunswick, E3B 5A3, Canada
- Faculty of Forestry and Environmental Management, University of New Brunswick, Fredericton, New Brunswick, E3B 5A3, Canada
| | - Michelle A Gray
- Canadian Rivers Institute, University of New Brunswick, Fredericton, New Brunswick, E3B 5A3, Canada
- Faculty of Forestry and Environmental Management, University of New Brunswick, Fredericton, New Brunswick, E3B 5A3, Canada
| | - Karen A Kidd
- Department of Biology and School of Geography and Earth Sciences, McMaster University, Hamilton, Ontario, L8S 4K1, Canada
- Canadian Rivers Institute, University of New Brunswick, Saint John, New Brunswick, E2L 4L5, Canada
| | - Michael S Duffy
- Canadian Rivers Institute, University of New Brunswick, Fredericton, New Brunswick, E3B 5A3, Canada
- Department of Biology, University of New Brunswick, Fredericton, New Brunswick, E3B 5A3, Canada
| | - Jennifer Lento
- Canadian Rivers Institute, University of New Brunswick, Fredericton, New Brunswick, E3B 5A3, Canada
- Department of Biology, University of New Brunswick, Fredericton, New Brunswick, E3B 5A3, Canada
| | - Wendy A Monk
- Environment and Climate Change Canada at Canadian Rivers Institute, Faculty of Forestry and Environmental Management, University of New Brunswick, Fredericton, New Brunswick, E3B 5A3, Canada
| |
Collapse
|