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Yaniv Hakim Stuart J Rowland Jeff A Guy Charles Mifsud Zehava Uni & Sheenan Harpaz 《Aquaculture Research》2007,38(4):361-372
The activity of the enzymes located in the digestive tract (pyloric caeca and intestine) in two strains and F1 crosses of the Australian freshwater fish silver perch [Murray River (M) and Cataract Dam (C)] was evaluated. The effect of the fish holding system (cages or ponds) on the activity of alkaline phosphatase (AP) and the brush border enzymes: maltase, leucine amino peptidase (LAP) and γ‐glutamyl transferase (γ‐GT) was examined. The enzymatic activity was tested in three intestinal sections: the pyloric caeca, upper and lower intestine. All the tested enzyme activities were influenced by an interaction between the intestinal section and the strain or cross of silver perch. For fish maintained in ponds, there were two distinct enzymatic activity patterns, one for the pure strains (C × C and M × M) and one for the crosses (C × M and M × C). Significantly higher (P<0.05) enzymatic activities of the crosses compared with the pure strains were particularly noticeable in the pyloric caeca. In fish held in cages, there was a significantly higher (P<0.05) enzymatic activity in the pyloric caeca of the C × C strain. The total enzymatic activities in the fish reared in the ponds were significantly higher (P<0.05) than those in the fish held in cages. The results of the present investigation confirm that the different genetic background of the silver perch in the Murray River and in the Cataract Dam influences the activity of the brush border digestive enzymes. This activity also varies between maintenance systems. 相似文献
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The digestive enzymes (proteases, carbohydrases and lipases) present along the alimentary tract of juveniles and adults of Diplodus puntazzo were studied. The data obtained showed a different distribution of the enzymatic activities in the different parts of the alimentary tract. Levels of enzymatic activity in the adults were higher than those measured in juveniles, suggesting that adults have a greater ability to digest larger pieces of food. The enzymatic pattern of D. puntazzo justifies its omnivorous habit and suggests an high potential for digesting vegetable polysaccharides. The results of this study suggest the need to adapt the diet to the digestive potential of this new farming species, thus contributing to the attainment of a product that is qualitatively more similar to the wild one. 相似文献
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I. Ferrante R. Ricci E. Aleo S. Passi S. Cataudella 《Aquaculture (Amsterdam, Netherlands)》2008,279(1-4):182-187
Bluefin Tuna (Thunnus thynnus L.) is a fish species of high nutritional and commercial value that is increasingly farmed in the Mediterranean basin. Oxidative stress research in aquaculture is particularly important in the assessment of both the health of farmed fish and seafood quality. Reactive oxygen species (ROS) are able to start the lipid peroxidation process which is potentially dangerous in fish, since they contain a high percentage of n-3 polyunsaturated fatty acids, in particular C20:5 n-3 and C22:6 n-3, which account for most of seafood's nutritional quality. The study of the antioxidant system and how the various components interact to delay post-harvest lipid peroxidation covers both the improvement of quality and the extension of shelf life of the fresh tuna product.In this study, hepatic antioxidant enzymes (catalase—CAT, superoxide dismutase—SOD and glutathione peroxidase—GPx) and lipid peroxidation levels (TBARS) of wild and sea cage-reared tunas were investigated. The aim was to examine the possible oxidative stress state of wild tunas killed by different fishing methods, compared with reared specimens exposed to different periods of confinement but killed by the same method.No significant differences between wild specimens were found in relation to catching techniques. A significant depletion was observed in liver SOD activity in reared tunas (5.00 U/mg protein) in comparison with wild specimens (5.90 U/mg protein). No differences in liver CAT activity between wild and reared tunas were found. In reared specimens we observed an oxidative stress state indicated by an increase in GPx activity (104.70 U/mg protein and 0.83 U/mg protein in reared and wild tunas, respectively). A significantly higher liver lipid content was observed in reared tunas, but no significant differences between wild and reared tunas in terms of TBA reactive substances content were found (2.03 vs 2.02 micromol TBARS/mg lipid). Our results suggest that the increased GPx activity leads to the suppression of lipid peroxidation in liver of reared tunas. This is the first time that antioxidant enzyme activities have been assayed in Bluefin Tuna and the stress state seems to be related to the diet of reared specimens rather than to their confinement, as indicated by the absence of differences in the antioxidant activities related to the period of confinement. 相似文献
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Histochemical and immunohistochemical characterization of rodlet cells in the intestine of two teleosts,Anguilla anguilla and Cyprinus carpio 
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下载免费PDF全文 G Bosi J A DePasquale M Manera G Castaldelli L Giari B Sayyaf Dezfuli 《Journal of fish diseases》2018,41(3):475-485
Rodlet cells (RC) are characterized by a distinctive cell cortex and conspicuous inclusions named “rodlets.” These cells are particularly abundant and large in size in intestine of eels. Histochemical, immunohistochemical and ultrastructural investigations were carried out on European eel Anguilla anguilla and Common carp Cyprinus carpio from Northern Italy. Eight biotinylated lectins were used to probe for specific carbohydrate residues in deparaffinized, hydrated intestinal sections of eel and carp. Five antibodies were tested on intestinal sections of both fish species: inducible nitric oxide synthase (i‐NOS), leu‐enkephalin, lysozyme, serotonin and tumour necrosis factor‐α. Lectin histochemistry revealed rodlet cells (RCs) of the eel intestine to react with two of the eight lectins tested, specifically Concanavalin A (ConA) and Sambucus Nigra Agglutinin (SNA). This contrasted to lectin staining of RCs in the intestine of common carp, where four of the eight lectins showed a positive reaction; Dolichos Biflorus Agglutinin (DBA), Wheat Germ Agglutinin (WGA), SNA and ConA. RCs in eel and carp intestine were immunoreactive with antibodies to lysozyme and i‐NOS. The occurrence of the inflammatory peptides lysozyme and i‐NOS in RCs of the eel and common carp poses in favour that these cells are involved in the mechanism of defence against pathogens. 相似文献
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草鱼和青鱼消化酶的分布特性 总被引：4，自引：0，他引：4
选择草鱼(C tenopharyngodon idellus)和青鱼(Mylopharyngodon piceus)作试验鱼,对它们消化道的酸性蛋白酶、碱性蛋白酶、淀粉酶以及三酰基甘油脂酶沿消化道及肝脏和胰腺中的活性分布进行了比较研究。研究表明:这些酶在消化道中呈现不同的分布规律,在肝脏和胰腺中酶的活性高于在消化道中相应酶的活性;同种鱼不同消化酶的分布有所差别;两种鱼消化组织中的各种酶活性分布规律也有差别;青鱼和草鱼的主要消化酶在不同消化器官中的分布有较大差别。 相似文献
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Linna Danne Lisa Horn Anita Feldhaus Daniel Fey Sebastian Emde Heike Schütze Mikolaj Adamek John Hellmann 《Journal of fish diseases》2022,45(1):69-76
Viral infections have been suggested to play a role in the decline of the panmictic population of the European eel (Anguilla anguilla). However, despite the importance of knowledge about pathogenic eel viruses, little is known about their spread in the wild European eel population and only a few eel pathogenic viruses have been described so far. In this study, we aimed to investigate the health status of the A. anguilla stock in North Rhine Westphalia (NRW) State of Germany. For this purpose, we examined tissue samples of 16 elvers, 100 yellow eels and 6 silver eels, sampled from the rivers Rhine, Lippe and Ems. Virus detection was performed via a combination of cell culture and PCR. Next to the detection of frequently encountered pathogenic eel viruses (anguillid herpesvirus 1 and eel virus European X (EVEX)), we isolated the eel picornavirus 1 (EPV-1) from tissue of yellow eels and elvers and demonstrate the distribution of EPV-1 in wild eel population in NRW. 相似文献
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实验对野生和养殖银鲳胃、幽门盲囊、前肠、中肠、后肠菌群结构进行了定性对比分析,并对产蛋白酶、淀粉酶、脂肪酶、纤维素酶的菌株进行了鉴定。结果发现,野生和养殖种群的消化道菌群结构存在较大差异,且同一种群消化道各部分之间菌群结构也存在较大差异。尽管养殖和野生银鲳均在幽门盲囊中具有最多的可培养细菌菌株,但野生银鲳消化道内主要菌群为嗜冷菌属(Psychrobacter)和Pseudochrobactrum,养殖银鲳消化道主要菌群为不动杆菌属(Acinetobacter)和假单孢菌属(Pseudomonas),两种群共有细菌仅一株,即Psychrobacter piscatorii strain VSD503,但其分别存在于野生与养殖种群银鲳消化道的不同部位。在产酶菌株筛选中发现,野生银鲳消化道内分离到16株产酶菌,其中44%可培养菌能产蛋白酶,56%能产淀粉酶,11%能产脂肪酶,56%能产纤维素酶,部分菌株可产2株以上的消化酶,其中产3种以上酶的菌株有5株,且产酶量丰富。相对于野生银鲳,养殖银鲳消化道内分离到22株产酶菌,主要以产蛋白酶和淀粉酶为主,70%可培养菌可产蛋白酶,21%可产淀粉酶,仅Bacillus thuringiensis strain VITGS可产纤维素酶,无一株菌产脂肪酶,其中只有Bacillus thuringiensis strain VITGS产3种酶但产酶量相对较少。研究可为银鲳人工养殖中潜在益生菌的筛选提供理论依据。 相似文献
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Increased abundance of European eel (Anguilla anguilla) in acidified Norwegian rivers after liming 下载免费PDF全文
下载免费PDF全文 Bjørn M. Larsen Trygve Hesthagen Eva B. Thorstad Ola H. Diserud 《Ecology of Freshwater Fish》2015,24(4):575-583
The prevalence and abundance (density 100 m?2) of European eel (Anguilla anguilla) were studied by means of electrofishing in 13 acidified rivers in Norway that had been limed to restore acceptable water quality for Atlantic salmon (Salmo salar). Status of Atlantic salmon in these rivers varied prior to liming, from being entirely lost in six highly acidified rivers and in different stages of decline in seven less acidified rivers. Four of the rivers are heavily affected by hydropower development. The abundance and prevalence of European eel increased significantly during the study period. The best model for predicting eel abundance was that with four explanatory variables: time after liming, time after liming squared, status of salmon stocks and hydropower regulation. The eel density was expected to increase by a factor of almost 5 after 10 years of liming. The model also predicts that a river with a formerly reduced Atlantic salmon stock has a 2.8 times higher density of eel than rivers with formerly lost salmon stocks. Before liming, European eel were on average recorded at 15 and 41% of the sampling stations in rivers with formerly lost and reduced Atlantic salmon populations, respectively, increasing to 49 and 68% in individual rivers, respectively, after 10 years of liming. The recovery of European eel in these formerly acidified rivers by means of liming took place during the same period as their abundance declined in other parts of their distribution area in Norway and elsewhere in Europe. 相似文献
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Comparative study of digestive enzymes in fish with different nutritional habits. Proteolytic and amylase activities 总被引：27，自引：0，他引：27
This work provides a comparative study of the proteolytic and amylase activities in six species of fish with different nutritional habits: rainbow trout (Oncorhynchus mykiss), gilthead seabream (Sparus aurata), European eel (Anguilla anguilla), common carp (Cyprinus carpio), goldfish (Carassius auratus), and tench (Tinca tinca). Trout and carp showed the highest digestive proteolytic activity. When proteolytic activity was determined in a wide range of pHs, the highest values in the digestive tract of all species were found at alkaline pHs, except in eel where activity could be detected only at acid pHs. Eel showed the lowest digestive proteolytic potential among all the species studied. With respect to amylase activity, the omnivorous species presented higher activity than did the carnivores. Among the carnivorous species, the lowest activity was found in trout. The ratio of total amylase:total proteolytic activity was higher in omnivorous fish species, the carp having the greatest value, whereas in trout this ratio was lower than one. Digestive enzyme activity declined as the incubation temperature decreased, but this trend varied depending on the fish species and the tissue analyzed. 相似文献
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F. M. Rueda J. A. López F. J. Martínez S. Zamora P. Divanach & M. Kentouri 《Aquaculture Nutrition》1997,3(3):161-165
The total fat content and the fatty acids of total lipids (TL), phospholipids (PL) and triacylglycerols (TAG) were analysed in white muscle from wild and reared red porgy, Pagrus pagrus (L.). The fat percentage was higher in reared (3.03 ± 0.57%) (mean ± SE) than wild (0.65 ± 0.03%) fish. The fatty acid pattern of reared porgy TL reflected the diet's lipid. Wild red porgy showed higher levels of ω3 and ω6 polyunsaturated fatty acids (PUFA) than reared, but both the atherogenic index and the index of thrombogenicity were very low for both wild and reared red porgy. The lipid fractions showed that the PL were composed of very high levels of PUFA, especially 22:6ω3, and their composition seemed to be better regulated than the composition of TAG. TAG showed greater differences between wild and reared fish, presumably because they reflected the dietary content of lipids. PUFA were the principal component of wild red porgy TAG. 相似文献
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G. Caruso M. G. Denaro R. Caruso F. De Pasquale L. Genovese G. Maricchiolo 《Fish physiology and biochemistry》2014,40(5):1373-1382
An experiment was carried out in red porgy, Pagrus pagrus (Teleostei, Sparidae), to assess the effects of a 14-day fasting period, followed by refeeding to apparent satiation, on the contents of digestive enzymes (total proteases, and particularly pepsin, trypsin, chymotrypsin, carboxypeptidases A and B; amylase and lipase). Two fish groups were considered: one (indicated as fasted/refed group) was fasted for 14 days and then refed during further 7 and 15 days, and the other was fed throughout the study and was taken as a control group. The measured enzymatic values showed that fasting resulted in a generalized, not significant decrease, of the activity of digestive enzymes. Refeeding caused a significant increase for most of the assayed enzymes: total proteases both in the middle and distal intestine, pepsin in the stomach, trypsin in the middle intestine, and amylase and lipase in the proximal intestine. Nevertheless, the detection in the fasted/refed fish of enzymatic values still lower than those measured in the control fish suggested that fish experiencing short-term fasting were partially impaired in their digestive capacity. 相似文献
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Wild‐catch eels with low fat content are either not accepted at all or accepted as a lower‐quality and less valuable product in the global eel market. This study was undertaken with the goal of increasing the fat content of yellow shortfin eel, Anguilla australis (104 ± 11 g initial weight), captured in the wild and kept in captivity for a short period, as well as assessing their rate of growth. An 86‐d feeding trial was conducted indoors in a recirculation aquaculture system, at 25.5 ± 1.6 C. Two commercial extruded dry feeds were tested; one formulated for European eel and one not specifically intended for use on eels. Good values of specific growth rate (1.10 and 1.12%/d) and feed conversion ratio (1.01 and 1.10) were achieved with both tested feeds. At the end of the trial, eels achieved 20–22% total fat, starting from wild fish with 7% fat content. Fat quality of the fattened eel was appreciably superior (higher proportion of omega‐3 fatty acids) than the fat of eels captured in the wild. The results of this study are encouraging for the prospect of fattening yellow shortfin eels and obtaining a market‐oriented eel product. 相似文献
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Daily rhythms of digestive physiology, metabolism and behaviour in the European eel (Anguilla anguilla) 总被引：1，自引：0，他引：1
J. F. López-Olmeda I. López-García M. J. Sánchez-Muros B. Blanco-Vives R. Aparicio F. J. Sánchez-Vázquez 《Aquaculture International》2012,20(6):1085-1096
Circadian rhythms are common in a wide variety of physiological processes. Our knowledge of biological rhythms in fish can be exploited to improve some key aspects of aquaculture such as feed optimization and fish welfare. The aim of this paper was to investigate daily rhythms in behavioural and physiological variables of the European eel. To this end, we first analysed the daily rhythms in locomotor activity measured by means of infrared photocells and feeding activity by means of self-feeders. The eels were then submitted to scheduled feeding (single meals once a day at a fixed time), and the levels of cortisol, glucose and digestive enzymes were analysed. Locomotor activity was predominantly nocturnal (63?% of daily activity occurring at night) with peaks located around light transitions, whereas feeding activity was less clearly defined. Cortisol and glucose showed daily rhythms, with acrophases located in the middle and at the beginning of the light phase, respectively, which should be carefully considered when using these parameters as welfare indicators. Significant variations were found during the day in acid protease levels, which increased in anticipation of mealtime. Taken together, these results describe for the first time a picture of the circadian physiology of the European eel, providing hints to improve feeding methods and welfare assessment. 相似文献
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Abstract – Populations of shortfinned eel ( Anguilla australis ) and longfinned eel ( A. dieffenbachii ) were sampled at randomly chosen sites along the length of three New Zealand streams during summer for three consecutive years to determine their variability in size distribution between streams, reaches (within streams) and years. The longfinned eel was numerically dominant in two of the streams, whereas the shortfinned eel was more abundant in the third stream. For comparisons, the data were stratified into 100-mm size classes for eels ≤600 mm long, whereas eels >600 mm were pooled into a single class. Log-linear analysis indicated that the size distribution of both species differed significantly between streams. Moreover, the size distribution of shortfinned, but not longfinned eels, differed significantly between reaches. Neither species showed significant change in size distribution between years. In contrast to the shortfinned eel, the density of longfinned eel ≤100 mm long was consistently low for all three years, which probably indicates poor recruitment. 相似文献