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981.
J R López S Núñez B Magariños N Castro J I Navas R de la Herran A E Toranzo 《Journal of fish diseases》2009,32(7):603-610
The first isolation of Tenacibaculum maritimum from wedge sole, Dicologoglossa cuneata, is reported. The pathogen was recovered from ulcers of cultured fish, from three different outbreaks. The six isolates obtained were biochemically and serologically characterized and diagnosis was confirmed by polymerase chain reaction using specific primers and partial 16S rRNA gene sequencing. The isolates constituted a homogeneous phenotypic group; however, they belong to two of the different serotypes described within this species. A virulence evaluation of the isolates using Wedge sole fry was also performed. 相似文献
982.
Lee LE Van Es SJ Walsh SK Rainnie DJ Donay N Summerfield R Cawthorn RJ 《Journal of fish diseases》2006,29(8):467-480
Neoparamoeba pemaquidensis is an ubiquitous amphizoic marine protozoan and has been implicated as the causative agent for several diseases in marine organisms, most notably amoebic gill disease (AGD) in Atlantic salmon. Despite several reports on the pathology of AGD, relatively little is known about the protozoan and its relationship to host cells. In this study, an in vitro approach using monolayers of a rainbow trout gill cell line (RTgill-W1, ATCC CRL-2523) was used to rapidly grow large numbers of N. pemaquidensis (ATCC 50172) and investigate cell-pathogen interactions. Established cell lines derived from other tissues of rainbow trout and other fish species were also evaluated for amoeba growth support. The amoebae showed preference and highest yield when grown with RTgill-W1 over nine other tested fish cell lines. Amoeba yields could reach as high as 5 x 10(5) cells mL(-1) within 3 days of growth on the gill cell monolayers. The amoebae caused visible focal lesions in RTgill-W1 monolayers within 24 h of exposure and rapidly proliferated and spread with cytopathic effects destroying the neighbouring pavement-like cells within 48-72 h after initial exposure in media above 700 mOsm kg(-1). Disruption of the integrity of the gill cell monolayers could be noted within 30 min of exposure to the amoeba suspensions by changes in transepithelial resistance (TER) compared with control cell monolayers maintained in the exposure media. This was significantly different by 2 h (P < 0.05) compared with control cells and remained significantly different (P < 0.01) for the remaining 72 h that the TER was monitored. The RTgill-W1 cell line is thus a convenient model for growing N. pemaquidensis and for studying host-pathogen interactions in AGD. 相似文献
983.
L. Gan Y.‐J. Liu L.‐X. Tian H.‐J. Yang Y.‐R. Yue Y.‐J. Chen J.‐J. Liang G.‐Y. Liang 《Aquaculture Nutrition》2012,18(6):589-598
A 63‐day growth trial was undertaken to estimate the effects of supplemented lysine and methionine with different dietary protein levels on growth performance and feed utilization in Grass Carp (Ctenopharyngodon idella). Six plant‐based practical diets were prepared, and 32CP, 30CP and 28CP diets were formulated to contain 320 g kg?1, 300 g kg?1 and 280 g kg?1 crude protein without lysine and methionine supplementation. In the supplementary group, lysine and methionine were added to formulate 32AA, 30AA and 28AA diets with 320 g kg?1, 300 g kg?1 and 280 g kg?1 dietary crude protein, respectively, according to the whole body amino acid composition of Grass Carp. In the groups without lysine and methionine supplementation, weight gain (WG, %) and specific growth rate (SGR, % day?1) of the fish fed 32CP diet were significantly higher than that of fish fed 30CP and 28CP diets, but no significant differences were found between 30CP‐ and 28CP‐diet treatments. WG and SGR of the fish fed 32AA and 30AA diets were significantly higher than that of fish fed 28AA diets, and the performance of grass carp was also significantly improved when fed diets with lysine and methionine supplementation (P < 0.05), and the interaction between dietary protein level and amino acid supplementation was noted between WG and SGR (P < 0.05). Feed intake (FI) was significantly increased with the increase in dietary protein level and the supplementation of lysine and methionine (P < 0.05), but feed conversion ratio (FCR) showed a significant decreasing trend (P < 0.05). Two days after total ammonia nitrogen (TAN) concentration test, the values of TAN discharged by the fish 8 h after feeding were 207.1, 187.5, 170.6, 157.3, 141.3 and 128.9 mg kg?1 body weight for fish fed 32CP, 32AA, 30CP, 30AA, 28CP and 28AA diets, respectively. TAN excretion by grass carp was reduced in plant‐based practical diets with the increase in dietary protein level and the supplementation of lysine and methionine (P < 0.05). The results indicated that lysine and methionine supplementation to the plant protein sources‐based practical diets can improve growth performance and feed utilization of grass carp, and the dietary crude protein can be reduced from 320 g kg?1 to 300 g kg?1 through balancing amino acids profile. The positive effect was not observed at 280 g kg?1 crude protein level. 相似文献
984.
R. A. Cunjak 《Ecology of Freshwater Fish》1992,1(1):26-34
Abstract– The diet composition, movcments and growth of Atlantic salmon parr rearing in the estuary of Western Arm Brook, Newfoundland were compared with those of parr from riverine habitats over 2 years. Estuarine parr consumed a variety of prey, including many freshwater taxa (mainly insects), which indicated a dependence on freshwater drift from the river. Prey of estuarine origin (amphipods and sticklebacks) were increasingly consumed between spring and autumn. Prey volume per fish and number of prey per fish increased significantly for estuarine parr between spring and autumn, suggesting an improvement in food availability. Riverine parr, however, realized a general decrease in both parameters between spring and autumn. The recapture of 16% ( n = 131) of the 829 parr marked in the estuary in 1987 and 1988 indicated a directed movement toward the head of the estuary and river mouth, as also suggested by the diet analysis. Parr from outer estuary sites were very mobile compared with parr from the estuary site closest to the river mouth, which behaved more like parr in the river proper in displaying strong site fidelity. Movement patterns of parr were primarily along the shoreline. Individual growth rates were highly variable in both environments but especially in the estuary. The mean growth of estuarine parr was 0.23 mm. d−1 between May and October with some evidence of fastest growth having occurred in late spring and early summer (approx. 0.4 mm. d−1 ); mean growth rate of riverine parr was slower, at 0.12 mm. d−1 . The results are discussed in the context that estuarine rearing by salmon parr represents an alternative life-history tactic for the species in river systems in eastern Canada. 相似文献
985.
K. L. Worrall C. G. Carter R. J. Wilkinson M. J. R. Porter 《Aquaculture International》2011,19(6):1075-1082
The efficacy of photoperiod manipulation to influence growth and developmental processes is well documented in a range of
temperate aquaculture species. However, the application of such techniques with tropical species requires further investigation.
This preliminary 20-day study investigated the influence of continuous photoperiod on growth of barramundi (Lates calcarifer). In addition, diel plasma melatonin profiles provided a physiological measure of how the endocrine system of barramundi
responded to continuous photoperiod. Juvenile barramundi (1.33 ± 0.02 g) were held in recirculation systems under 12-h light:
12-h dark (12L:12D) or 24-h light (24L:0D) with a light intensity of 1,000 lux throughout the water column. Fish from both
treatments grew to more than 14 times their original weight, with final weight (24L:0D = 21.59 ± 0.85 g; 12L:12D = 19.12 ± 0.55 g),
total length (24L:0D = 12.67 ± 0.14 cm; 12L:12D = 11.96 ± 0.13 cm) and specific growth rate (24L:0D = 9.60 ± 0.05% bw day−1; 12L:12D = 9.14 ± 0.06% bw day−1) being significantly higher for fish grown on 24L:0D compared with 12L:12D. There were no significant differences in feed
intake (24L:0D = 226.46 ± 6.27 g; 12L:12D = 219.02 ± 5.73 g) or feed conversion ratio (24L:0D = 0.71 ± 0.06; 12L:12D = 0.80 ± 0.07)
between light treatments. Barramundi held under 12L:12D exhibited diel melatonin secretion, which peaked mid-dark phase (171.83 ± 4.81 pg ml−1) followed by a gradual decrease in base levels at the onset of illumination (68.61 ± 8.77 pg ml−1). When juvenile barramundi were subjected to 24L:0D, the amplitude of peak melatonin secretion was significantly suppressed
during the subjective mid-dark phase (129.71 ± 2.36 pg ml−1). This preliminary study confirmed that barramundi respond to photoperiod manipulation in a similar manner to many temperate
fish species, thus demonstrating the future potential use of artificial lighting to improve growth in this species commercially. 相似文献
986.
Yoganandhan K Syed Musthaq S Narayanan RB Sahul Hameed AS 《Journal of fish diseases》2004,27(9):517-522
The VP28 gene of white spot syndrome virus (WSSV) was cloned into pRSET B expression vector. The VP28 protein was expressed as a protein with a 6-histidine taq in Escherichia coli GJ1158 with NaCl induction. Antiserum was raised against this recombinant-VP28 protein in rabbits and it recognized VP28 protein in naturally and experimentally WSSV-infected shrimp, marine crabs, freshwater prawns and freshwater crabs. The antiserum did not recognize any of the other known WSSV structural proteins. Various organs such as eyestalks, head muscle, gill tissue, heart tissue, haemolymph, tail tissue and appendages were found to be good materials for detection of WSSV using the antiserum and detection of WSSV was successful in experimentally infected Penaeus monodon and P. indicus at 12 and 24 h post-infection (p.i.), respectively. The antiserum was capable of detecting WSSV in 5 ng of total haemolymph protein from WSSV-infected shrimp. 相似文献
987.
Aqueous and ethanol extracts of Acacia pennata (bark), Catunaregam uliginosa (fruit), Diospyros lenceofolia (fruit), and Sapindus mukorossi (fruit) were evaluated as piscicides on the freshwater fish Danio dangila, Danio rerio, and Puntius shalynius, and the air-breathing Heteropneustes fossilis. Catunaregam uliginosa (fruit) possessed relatively higher piscicidal potency followed by Sapindus mukorossi (fruit), Acacia pennata (bark), and lastly Diospyros lanceofolia (fruit). Catunaregam uliginosa can thus be used for eradicating unwanted wild fishes in a short time span at low concentrations so that the health of aquatic environment is maintained. 相似文献
988.
The transmission of viral encephalopathy and retinopathy (VER) was investigated in juvenile sea bream, Sparus aurata L. Two different infection routes [intraperitoneal (i.p.) and intramuscular injection (i.m.)] were tested at two different temperatures (20 and 26 °C) using sea bream of mean weight 0.7, 2 and 4 g, as well as an immersion challenge performed at 26 °C with sea bream of 0.7 g. Successful transmission of the disease was only achieved by i.m. injection. Mortalities of 100% occurred in sea bream of 0.7 g at day 15 post-infection and 47% in sea bream of both 2 and 4 g at day 30 post-infection in all the experimental infections at 26 °C. No mortalities were ever observed with infections at 20 °C. When mortalities were observed, the virus was detected by immunoperoxidase staining in the SSN-1 cell line inoculated with tissues from infected fish. Histological examination of both normal and infected fish showed a vacuolization in the bipolar and granular layers of the retina of the infected sea bream. This is the first experimentally induced transmission of VER in sea bream. Differences were observed at the time of disease onset depending on water temperature, the route of infection and the age of the juvenile fish. 相似文献
989.
R. L. THUNE MAUREEN C. JOHNSON T. E. GRAHAM R. L. AMBORSKI 《Journal of fish diseases》1986,9(1):55-61
Abstract. A single step procedure for purification of B-haemolysin from Aeromonas hydrophila is described which recovered 94% of the haemolytic activity with a sixfold increase in specific activity. Toxicity of haemolysin in 0-group channel catfish was 0–6 mg of purified protein per gram offish. Of six strains of A. hydrophila evaluated for differential toxin production and virulence in 0-group channel catfish, three B-haemolysin-deficient strains were virulent while three B-haemolysin-producing strains were avirulent. 相似文献
990.
Graham D Raby Jessica R Packer Andy J Danylchuk Steven J Cooke 《Fish and Fisheries》2014,15(3):489-505
The assumption that animals released from fishing gears survive has frequently been scrutinized by researchers in recent years. Mortality estimates from these research efforts can be incorporated into management models to ensure the sustainability of fisheries and the conservation of threatened species. Post‐release mortality estimates are typically made by holding the catch in a tank, pen or cage for short‐term monitoring (e.g. 48 h). These estimates may be inaccurate in some cases because they fail to integrate the challenges of the wild environment. Most obvious among these challenges is predator evasion. Stress and injury from a capture experience can temporarily impair physiological capacity and alter behaviour in released animals, a period during which predation risk is likely elevated. In large‐scale commercial fisheries, predators have adapted their behaviour to capitalize on impaired fishes being discarded, while in recreational catch‐and‐release fisheries, exercise and air exposure can similarly impede the capacity for released fish to evade opportunistic predators. Owing to the indirect and often cryptic nature of this source of mortality, very few studies have attempted to document it. A survey of the literature demonstrated that <2% of the papers in the combined realms of bycatch and catch‐and‐release have directly addressed or considered post‐release predation. Future research should combine field telemetry and laboratory studies using both natural and simulated predation encounters and incorporate physiological and behavioural endpoints. Quite simply, predation is an understudied and underappreciated contributor to the mortality of animals released from fishing gears. 相似文献