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Gill Disease (gill + disease)
Kinds of Gill Disease Selected AbstractsGill disease of marine fish caused by infection with Neoparamoeba pemaquidensisJOURNAL OF FISH DISEASES, Issue 9 2001B L Munday Amoebic gill disease (AGD) of maricultured salmonids, turbot, Scophthalmus maximus (L.), European seabass, Dicentrarchus labrax (L.), and sharpsnout seabream, Diplodus puntazzo (Cetti), caused by Neoparamoeba pemaquidensis has been reported from Australia (Tasmania), Ireland, France, Chile, North America (Washington State and California) and Spain. Of the salmonids, Atlantic salmon, Salmo salar L., appears to be the most susceptible with rainbow trout, Oncorhynchus mykiss (Walbaum), also suffering significant disease. Only minor outbreaks have been reported in coho, O. kisutch (Walbaum), and chinook salmon, O. tshawytscha (Walbaum). The disease now accounts for 10,20% of production costs of Atlantic salmon in Tasmania and has lead to temporary abandonment of culture of this species in parts of Spain. It is of lesser, but still significant, importance in other countries. Much is known about the pathology of AGD but the pathophysiology of the disease is poorly understood. There is evidence that non-specific immunity is involved in fish acquiring resistance to AGD, but no unequivocal evidence exists for protection as a result of specific immune responses. To date, for salmonids, the only effective treatment for AGD is a freshwater bath. Control procedures based on modification of management strategies have been minimal and virtually unresearched. [source] Antarctic fish can survive prolonged exposure to elevated temperaturesJOURNAL OF FISH BIOLOGY, Issue 7 2008E. Robinson The Antarctic notothenioid Pagothenia borchgrevinki was collected from the stenothermal waters of McMurdo Sound in the summers of 2004, 2005 and 2006. Acclimation ability at 4° C was tested in healthy P. borchgrevinki and in individuals infected with x-cell gill disease. All healthy fish successfully acclimated to 4° C, establishing compensatory changes in resting oxygen consumption rate (Rrest) and critical swimming speed (Ucrit) during a 1 month acclimation period, which were maintained during a longer, 6 month acclimation period. In contrast, individuals infected with x-cell disease were unable to acclimate to 4° C, demonstrating significantly reduced survival rates compared with healthy individuals at 4° C. Measurements of Rrest suggest that limitations in the ability of x-cell fish to uptake oxygen from the external milieu may have a negative effect on their survival at 4° C. [source] Amoebic gill disease resistance is not related to the systemic antibody response of Atlantic salmon, Salmo salar L.JOURNAL OF FISH DISEASES, Issue 1 2010R S Taylor Abstract Amoebic gill disease (AGD) is a proliferative gill tissue response caused by Neoparamoeba perurans and is the main disease affecting Australian marine farmed Atlantic salmon. We have previously proposed that macroscopic gill health (,gill score') trajectories and challenge survival provide evidence of a change in the nature of resistance to AGD. In order to examine whether the apparent development of resistance was because of an adaptive response, serum was sequentially sampled from the same individuals over the first three rounds of natural AGD infection and from survivors of a subsequent non-intervention AGD survival challenge. The systemic immune reaction to ,wildtype'Neoparamoeba sp. was characterized by Western blot analysis and differentiated to putative carbohydrate or peptide epitopes by periodate oxidation reactions. The proportion of seropositive fish increased from 46% to 77% with each AGD round. Antibody response to carbohydrate epitope(s) was immunodominant, occurring in 43,64% of samples. Antibodies that bound peptide epitope were identified in 16% of the challenge survivors. A 1:50 (single-dilution) enzyme-linked immunosorbent assay confirmed a measurable immune titre in 13% of the survivors. There was no evidence that antibodies recognizing wildtype Neoparamoeba provided significant protection against AGD. [source] Microfauna associated with amoebic gill disease in sea-farmed Atlantic salmon, Salmo salar L., smoltsJOURNAL OF FISH DISEASES, Issue 8 2006M L Bermingham Abstract A study of microfauna, associated with pathological changes in the gills of Atlantic salmon, Salmo salar L., was conducted over 2001,2002. Monthly samples of 1+ salmon smolts were taken, protozoan populations were quantified and gill health was assessed histologically. Protozoan densities were correlated with pathological changes, in order to determine their possible role in lesions in the gills. The most severe gill tissue changes were observed in summer/autumn and the least in spring. A diverse polyphyletic protozoan community was observed colonizing the gills, including Neoparamoeba sp., other amoebae, scuticociliates, Ichthyobodo -like flagellates, trichodinid ciliates and prostomatean ciliates. The earlier gill tissue changes in the gill were not always associated with the presence of these microorganisms, whereas amoebae (other than Neoparamoeba sp.), Ichthyobodo -like flagellates and trichodinid ciliates correlated with augmenting gill lesions. Neoparamoeba sp. was present, but its abundance did not correlate with the disease. This study suggests that a diversity of protozoans including Ichthyobodo -like flagellates, trichodinid ciliates and amoebae other than Neoparamoeba sp. are involved in the aetiology of amoebic gill disease in the Irish situation. [source] The effect of environmental factors on the distribution of Neoparamoeba pemaquidensis in TasmaniaJOURNAL OF FISH DISEASES, Issue 10 2005M Douglas-Helders Abstract Aquaculture in Tasmania is mostly carried out in estuaries. These estuarine habitats show a great variety and form unique environments in which Neoparamoeba pemaquidensis, the amoebic gill disease (AGD)-causing protozoan, may or may not survive. Tasmania is divided into two zones, one where AGD is present and one where AGD is absent, but any ecological data to rationalize this distribution is lacking. In in vitro trials N. pemaquidensis strains were exposed to different concentrations of ammonium sulphate, copper sulphate, copper sulphate and tannin, and different Neoparamoeba densities, salinities and temperatures. A trial using field water samples investigated the survival of N. pemaquidensis in waters sourced from AGD-free and AGD-positive zones, and water analysis was performed to determine any differences. Significantly decreased protozoan survival was found with exposure to increasing copper sulphate concentrations from 10 to 100 000,m (P < 0.001), salinity of 15, (P < 0.001), low Neoparamoeba densities of 625 and 1250 cells mL,1 (P = 0.0005), and water sourced from Macquarie Harbour (P < 0.001). The water chemistry of this AGD-free zone showed significantly lower dissolved calcium and magnesium concentrations which may contribute to this area being AGD-free. Understanding of the ecology of N. pemaquidensis will enable better control and prevention strategies for Tasmanian salmon growers. [source] Isolation of the salmonid rhamnose-binding lectin STL2 from spores of the microsporidian fish parasite Loma salmonaeJOURNAL OF FISH DISEASES, Issue 8 2005A Booy Abstract The microsporidian parasite, Loma salmonae, is the causative agent of gill disease in both wild and netpen-reared salmonids worldwide. In this paper we report the finding of a rhamnose-binding lectin from steelhead trout, Oncorhynchus mykiss, which was found bound in high concentration to the surface coat of L. salmonae spores. SDS-PAGE, immunoblot, N-terminal sequencing and mass spectrometric analyses were used to determine that the dominant 24 kDa protein lectin observed on SDS-PAGE analysis of intact spore extracts is the O. tshawytscha variant of the previously identified rhamnose-binding lectin STL2 from rainbow trout, O. mykiss. Although the physiological role of these lectins has not been clearly delineated, they have been implicated in a variety of functions, including inhibition of pathogenic bacteria by opsonization and macrophage-mediated tumour lysis. [source] Isolation and characterization of strains of Flavobacterium columnare from BrazilJOURNAL OF FISH DISEASES, Issue 4 2005H C P Figueiredo Abstract Flavobacterium columnare is an important pathogen of freshwater fish, implicated in skin and gill disease, often causing high mortality. An outbreak of skin disease in fingerling and adult Nile tilapia, Oreochromis niloticus (L.), cultivated in a recirculation system, was investigated. Four strains were isolated and characterized by biochemical reactions, enzyme production, fatty acid profile and analysis of the 16S-23S rDNA intergenic spacer region. All strains were identified as F. columnare. Experimental infection assays with one of these strains (BZ-5-02) were conducted and pathogenicity (by intramuscular route) was demonstrated in Nile tilapia and channel catfish, Ictalurus punctatus (Rafinesque). This is the first report of characterization of Brazilian strains of F. columnare. [source] Fusarium incarnatum isolated from black tiger shrimp, Penaeus monodon Fabricius, with black gill disease cultured in VietnamJOURNAL OF FISH DISEASES, Issue 9 2004L V Khoa Abstract Fusarium incarnatum was isolated from gill lesions of cultured black tiger shrimp, Penaeus monodon, in every crop during 2000,2002 in Nghe An province, Vietnam. Infected shrimps showed typical signs of black gill disease and mortalities about a month prior to harvest. Detailed morphological examinations, as well as molecular phylogenic analyses based on partial nucleotide sequences of ribosomal DNA, were made on the isolates. An artificial infection of kuruma prawn, Penaeus japonicus, using two selected isolates was also conducted and their pathogenicity determined. [source] Cardiac morphology in relation to amoebic gill disease history in Atlantic salmon, Salmo salar L.JOURNAL OF FISH DISEASES, Issue 4 2002M D Powell Fish from cages with histories of heavy and light amoebic gill disease (AGD) outbreaks were harvested and the morphology, histology and activities of lactate dehydrogenase determined. Although fish with a history of heavy AGD were smaller, their heart somatic indices were similar to those of fish with a history of light AGD. However, morphometrically the ratios of ventricle axis length and width and axis length and height were significantly higher, and there was an overall thickening of the muscularis compactum in the ventricle of fish with heavy AGD history. There was no difference in the lactate dehydrogenase activity of the ventricle muscle in the two fish groups. These results suggest that the change in ventricle shape associated with AGD was a possible compensation for an increased afterload where the lengthening of the ventricle was compensated for by an increase in muscle thickness, but without any overall ventricular hypertrophy or gain in ventricular mass. This suggests that AGD may be associated with cardiovascular compromise in affected fish. [source] Gill disease of marine fish caused by infection with Neoparamoeba pemaquidensisJOURNAL OF FISH DISEASES, Issue 9 2001B L Munday Amoebic gill disease (AGD) of maricultured salmonids, turbot, Scophthalmus maximus (L.), European seabass, Dicentrarchus labrax (L.), and sharpsnout seabream, Diplodus puntazzo (Cetti), caused by Neoparamoeba pemaquidensis has been reported from Australia (Tasmania), Ireland, France, Chile, North America (Washington State and California) and Spain. Of the salmonids, Atlantic salmon, Salmo salar L., appears to be the most susceptible with rainbow trout, Oncorhynchus mykiss (Walbaum), also suffering significant disease. Only minor outbreaks have been reported in coho, O. kisutch (Walbaum), and chinook salmon, O. tshawytscha (Walbaum). The disease now accounts for 10,20% of production costs of Atlantic salmon in Tasmania and has lead to temporary abandonment of culture of this species in parts of Spain. It is of lesser, but still significant, importance in other countries. Much is known about the pathology of AGD but the pathophysiology of the disease is poorly understood. There is evidence that non-specific immunity is involved in fish acquiring resistance to AGD, but no unequivocal evidence exists for protection as a result of specific immune responses. To date, for salmonids, the only effective treatment for AGD is a freshwater bath. Control procedures based on modification of management strategies have been minimal and virtually unresearched. [source] Development and validation of a new dot blot test for the detection of Paramoeba pemaquidensis (Page) in fishJOURNAL OF FISH DISEASES, Issue 5 2001M Douglas-Helders In this study, the development of a dot blot assay to assess amoebic gill disease (AGD) using non-lethal gill mucus samples is described and its performance validated by comparing the assay with the indirect fluorescent antibody test (IFAT), the ,gold standard' test. The agreement between the two tests was high, with a positive predictive value of 95% and negative predictive value of 93%, with a corrected , value of 0.88. The sensitivity and specificity of the test were 97 and 91%, respectively. The dot blot is both sensitive and specific for Paramoeba pemaquidensis and is formatted so that large numbers of samples can be conveniently analysed. [source] Production of salmonid amoebic gill disease by exposure to Paramoeba sp. harvested from the gills of infected fishJOURNAL OF FISH DISEASES, Issue 2 2001D Zilberg Atlantic salmon, Salmo salar L., were exposed to different concentrations of Paramoeba sp. The lowest concentration which induced amoebic gill disease (AGD) was 230 Paramoeba sp. L,1 and the severity of infection increased with increasing concentration. The concentration of Paramoeba sp. positively correlated with the number of gill lesions (R2 > 0.7). This study provides evidence that Paramoeba sp. is the causative agent of AGD and describes an experimental model that enables the severity of the induced disease to be controlled. [source] Impact of Copper Sulfate on Plankton in Channel Catfish Nursery PondsJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 1 2009Charles C. Mischke Many fish culturists are interested in applying copper sulfate pentahydrate (CSP) to channel catfish, Ictalurus punctatus, nursery ponds as a prophylactic treatment for trematode infection and proliferative gill disease by killing snails and Dero sp., respectively, before stocking fry. However, copper is an algaecide and may adversely affect phytoplankton and zooplankton populations. We evaluated the effects of prophylactic use of copper sulfate in catfish nursery ponds on water quality and phytoplankton and zooplankton populations. In 2006, treatments of 0 mg/L CSP, 3 mg/L CSP (0.77 mg/L Cu), and 6 mg/L CSP (1.54 mg/L Cu) were randomly assigned to 0.04-ha ponds. In 2007, only treatments of 0 and 3 mg/L CSP were randomly assigned to the 16 ponds. Ponds treated with CSP had significantly higher pH and significantly lower total ammonia concentrations. Treatment of both CSP rates increased total algal concentrations but reduced desirable zooplankton groups for catfish culture. CSP has been shown to be effective in reducing snail populations at the rate used in this study. CSP treatment also appears to be beneficial to the algal bloom, shifting the algal population to green algae and increasing total algal biomass within 1 wk after CSP treatment. Although zooplankton populations were adversely affected, populations of important zooplankton to catfish fry began rebounding 6,12 d after CSP treatment. Therefore, if CSP is used to treat catfish fry ponds of similar water composition used in this study, fry should not be stocked for about 2 wk after CSP application to allow time for the desirable zooplankton densities to begin increasing. [source] Comparative Cellular Morphology Suggesting the Existence of Resident Dendritic Cells Within Immune Organs of SalmonidsTHE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 4 2008Jan Lovy Abstract This report is the first morphological description of cells that resemble dendritic cells, which appear to form resident populations within the spleen and anterior kidney of fish. Based on examination of three salmonid species, including, rainbow trout, brook trout, and Atlantic salmon, the cells were most abundant in the spleen, although they were always present in the anterior kidney. The cells appeared diffusely distributed, often near blood vessels of the spleen and kidney of healthy fish and within the epithelium, connective tissue, and blood vessels of rainbow trout gills with experimentally induced microsoporidial gill disease. The dendritic-like cells in this study contained granules that resemble Birbeck granules, which are considered to be morphological markers of Langerhans cells in mammals. The cells were approximately 6 ,m in diameter and contained Birbeck-like (BL) granules localized near centrioles. Although the dendritic-like cells in the three salmonid species shared many similarities, morphological differences were found in the fine structure of the rod portion of the BL granules. Rainbow trout BL granules contained amorphous material, while the other salmonid species contained particulate material arranged in a square-lattice arrangement. The BL granules in the cells of Atlantic salmon had a narrow diameter and contained four layers of particulate material when sectioned longitudinally; two layers enveloped by the granule membrane and two central layers making up a central lamella, which is common in mammalian Birbeck granules. Anat Rec, 291:456,462, 2008. © 2008 Wiley-Liss, Inc. [source] Effects of different batches of Neoparamoeba perurans and fish stocking densities on the severity of amoebic gill disease in experimental infection of Atlantic salmon, Salmo salar L.AQUACULTURE RESEARCH, Issue 10 2010Philip B B Crosbie Abstract Currently, there are two methods of inducing laboratory-based amoebic gill disease (AGD) in Atlantic salmon, Salmo salar L.: cohabitation with infected fish or exposure to a suspension of amoebae. Amoebic gill disease cannot be induced with cultured amoebae; therefore, the only source of the infective organism is salmon with the disease. For experimental purposes and to maintain pathogen supply, salmon are kept in an infection tank and amoebae are isolated from salmon once the disease establishes. In this way, discrete batches of amoebae are collected periodically. This study investigated the infective ability of different batches of amoebae. Furthermore, the effect of stocking density of salmon on the progression of AGD was also examined. The infective ability of different batches of amoebae isolated periodically from AGD-affected salmon varied in terms of quantifiable pathology. Salmon stocking density had a significant impact on survival after amoebae challenge, with morbidity beginning 23 days post challenge in tanks stocked at 5.0 kg m,3 and 29 days for those stocked at 1.7 kg m,3. For uniform initiation of AGD in multiple tanks, amoebae batches should be equally divided and added to tanks until the required concentration is reached and to maintain a standard biomass between replicate tanks and treatments. [source] | ||||||||||