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Abstract. Populations of postlarval, juvenile and adult Kuruma prawns, Penaeus japonicus Bate, have been affected by an unusual proliferative condition of the midgut and ventral nerve cord. Animals affected with this gut and nerve syndrome have been observed from various shrimp systems in Hawaii, including high density tanks and raceways, low density ponds, and adult broodstock held in a maturation system. Affected shrimp ranged in age from ∼20-day-old postlarvae of ∼0.02g average weight to adult shrimp of ∼ 60 g average weight. The principal lesions observed in affected animals were a hypertrophy of the anterior midgut mucosal epithelium basement membrane (BM) and a hyperplasia of the epineurium that covers the ventral nerve cord and segmental ganglia in the gnathothorax. There seemed to be a positive correlation between increased thickness of the BM and disease, and possibly a relationship between ataxia and lethargy and the degree of hyperplasia of the epineurium. 相似文献
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J. FONSECA-MADRIGAL V. KARALAZOS P.J. CAMPBELL J.G. BELL & D.R. TOCHER 《Aquaculture Nutrition》2005,11(4):241-250
This study aimed to investigate the effects of dietary crude palm oil (CPO) on fatty acid metabolism in liver and intestine of rainbow trout. Triplicate groups of rainbow trout for 10 weeks at 13 °C were fed on diets in which CPO replaced fish oil (FO) in a graded manner (0–100%). At the end of the trial, fatty acid compositions of flesh, liver and pyloric caeca were determined and highly unsaturated fatty acid (HUFA) synthesis and fatty acid oxidation were estimated in isolated hepatocytes and caecal enterocytes using [1‐14C]18:3n‐3 as substrate. Growth performance and feed efficiency were unaffected by dietary CPO. Fatty acid compositions of selected tissues reflected the dietary fatty acid composition with increasing CPO resulting in increased proportions of 18:1n‐9 and 18:2n‐6 and decreased proportions of n‐3HUFA, 20:5n‐3 and 22:6n‐3. Palmitic acid, 16:0, was also increased in flesh and pyloric caeca, but not in liver. The capacity of HUFA synthesis from 18:3n‐3 increased by up to threefold in both hepatocytes and enterocytes in response to graded increases in dietary CPO. In contrast, oxidation of 18:3n‐3 was unaffected by dietary CPO in hepatocytes and reduced by high levels of dietary CPO in enterocytes. The results of this study suggest that CPO can be used at least to partially replace FO in diets for rainbow trout in terms of permitting similar growth and feed conversion, and having no major detrimental effects on lipid and fatty acid metabolism, although flesh fatty acid compositions are significantly affected at an inclusion level above 50%, with n‐3HUFA reduced by up to 40%. 相似文献
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Abstract. This study examined whether passive implantable transponder (PIT) tags could be used to mark individually juvenile snapper, Pagrus auratus (Bloch and Schneider), without affecting their growth. Fifty juvenile snapper (25 tagged and 25 untagged controls) were placed in each of four 2000–1 tanks. At the start of the experiment the snapper had a mean weight of 59 ± 18g (SD). After 70 days, the mean weight of all fish was 115 ± 31 g (SD) and there was no significant difference between the growth of tagged and untagged fish. Apparent tag loss ranged from 4 to 8%. 相似文献
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Abstract. The susceptibility of sablefish, Anoplopoma fimbria (Pallas), a potential candidate for commercial mariculture, to the devastating salmonid pathogen Renibacterium salmoninarum (Rs) and the pathology of the infection were investigated. Sablefish became moribund or died of apparently uncomplicated infections of Rs within 50-71 days following intrapcritoncal inoculation of the pathogen and pure cultures of Rs were re-isolated from some affected individuals. At least one sablefish carried the pathogen up to 165 days post-inoculation when the experiment was terminated. The pathology of the Rs infection in this strictly marine fish is described and the implication of the findings to the operation of salmon marinefarms is discussed. 相似文献
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Abstract. Lipid class and fatty acid analyses were carried out on eight batches of pre-fertilized eggs of Atlantic halibut, Hippoglossus hippoglossus (L.). These batches were classified as ‘viable’ or ‘non-viable’ according to fertilization rate, blastomere symmetry and incubation success. The lipid class and fatty acid compositions were very similar between egg categories with exception of cholesterol which was shown to be significantly greater in the ‘non-viable’ eggs. Polar lipid classes predominated (67·1% and 67·0% of the total lipid for ‘viable’ and ‘non-viable’ egg batches respectively), with phosphatidylcholine (PC) being the major class (43·2% and 43·5%) and triacylglycerol (TAG) the main neutral lipid class (18·8% and 17·8%). Gas liquid chromatography of fatty acid methyl esters from the total lipid revealed no significant differences in fatty acid composition. The fatty acid profiles of viable egg batches showed five major fatty acids 16:0 (17·3%), 18:0 (4·8%), 18:1n-9 (9%), 20:5n-3 (119%) and 22:6n-3 (25·9%). The results are discussed in terms of the potential role of lipids as egg quality determinants in fish. 相似文献
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IG BELL PJ NICHOLLS C. NORMAN AINI IDERIS† GM CROSS† 《Australian veterinary journal》1991,68(3):97-101
Meat chickens housed on a commercial broiler farm in Australia were vaccinated once at 10 to 11 days-of-age by aerosol with live V4 Newcastle disease virus (NDV) vaccine. Groups of vaccinated and unvaccinated birds were flown to Malaysia, where they were challenged with a virulent strain of NDV. Survival rates in vaccinated chickens challenged 7, 14, 21 or 31 d after vaccination were 0.47, 0.77, 0.97 and 0.92, respectively. All unvaccinated chickens died due to Newcastle disease (ND) following challenge. Chickens in Australia and Malaysia were bled and the serums tested for haemagglutination-inhibiting (HI) antibody to NDV. Many vaccinated birds with no detectable antibody, and all birds with a log2 titre of 2 or greater, survived challenge. The results showed that this V4 vaccine induced protective immunity in a significant proportion of chickens within 7 d of mass aerosol vaccination. This early immunity occurred in the absence of detectable circulating HI antibody. Non-HI antibody mediated immunity continued to provide protection up to 31 d after vaccination. Almost all vaccinated birds were protected within 3 w of vaccination. It is concluded that the V4 vaccine is efficacious and could be useful during an outbreak of virulent ND in Australia. 相似文献
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