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1.
Triploidization is an interesting tool to produce sterile fish. In the yellowtail tetra, Astyanax altiparanae, this can be applied for aquaculture and surrogate technologies. In this study, we compared the efficacy of cold (2 C) or heat shock (38 C, 40 C, and 42 C) on triploid induction in the yellowtail tetra. The eggs were treated with cold or heat shock, 2 min postfertilization (30 min in cold shock or 2 min in heat shock). Intact embryos served as the control group. Ploidy status was confirmed by karyotyping, flow cytometry, and nuclear diameter of erythrocytes. The hatching rate decreased after cold shock (12.69 ± 15.76%) and heat shock at 42 C (0.35 ± 0.69%) in comparison with the control group (63.19 ± 16.82%). At 38 C and 40 C, hatching rates (61.29 ± 17.73% and 61.75 ± 22.1%, respectively) were not decreased. Only one triploid arose at 38 C (1/80). At 40 C, a high number of triploids arose (72/78). At 42 C, very few embryos developed into the hatching stage. A large number of haploid individuals arose after cold shock (61/75), with only one triploid. Our results indicate that heat shocking of embryos at 40 C is optimum for triploid production in the yellowtail tetra.  相似文献   

2.
Fish Physiology and Biochemistry - This study interrogated factors which affect the appearance of secondary sexual characteristics, namely, fin spinelets (rigid dimorphic structure empirically...  相似文献   

3.
The anaesthetic potential of menthol was evaluated in lambari Astyanax altiparanae by exposing fingerlings to concentrations 50, 100, 150, 200, 250 and 300 mg L?1 and measuring the induction and recovery times to deep anaesthesia, the mortality rates during and 96 h after procedure and after 6 min of continuous exposure. The effect of menthol on stress responses were evaluated by comparing glucose and cortisol levels of juveniles subjected to anaesthesia (50 mg L?1), stress (air exposure) or pre‐anaesthesia associated to stress. All concentrations induced deep anaesthesia within 0.5 to 1 min, with recovery between 1.83 and 4.16 min, without mortality during the induction or up to 96 h after exposure. Induction time decreased and recovery time increased linearly as the menthol concentration increased. Continuous exposure to 50, 100 and 150 mg L?1 concentrations resulted in mortality rates of 0%, 20% and 80% respectively. Anaesthesia or air exposure increase blood glucose but prior anaesthesia with menthol suppressed the elevation of cortisol caused by stress. Menthol has an anaesthetic effect and attenuates the stress response in lambari and 50 mg L?1 is the most effective concentration for inducing deep anaesthesia in 1.0 min, safe for up to 6 min exposure.  相似文献   

4.
This study aimed to evaluate the effect of different levels of conjugated linoleic acid (CLA) on growth performance, carcass chemical composition and fatty acid profile of lambari (Astyanax altiparanae). A completely randomized experimental design with six treatments, diets with graded levels of CLA (0.0, 5.0, 10.0, 15.0, 20.0 and 25.0 g kg?1) and five repetitions. Fish (n = 570; weight: 1.58 ± 0.23 g) were distributed into 30 (70‐L) aquaria and fed the experimental diets during 90 days. No effects of dietary supplementation with CLA on fish performance and carcass chemical composition were observed. CLA influenced carcass fatty acid profile, a positive relationship was found for 16:1 n‐9, 18:1 n‐9, 18:2(cis‐9, trans‐11), 18:2(trans‐10, cis‐12) and 20:1 n‐9, and a negative relationship was found for 15:1 n‐7, 16:0, 16:1 n‐5, 18:2 n‐6, 18:3 n‐3, 20:5 n‐3 and 22:4 n‐6. Total CLA and monounsaturated fatty acids (MUFA) linearly increased with the increase in dietary CLA, while saturated fatty acids (SFA) and polyunsaturated fatty acids (PUFA) of n‐6 and n‐3 series linearly decreased. Dietary CLA can be incorporated into the lambari (A. altiparanae) muscle, and the fish can be used as functional foods, because CLA is related to the prevention of various diseases in humans.  相似文献   

5.
Fish Physiology and Biochemistry - In view of the established climate change scenario and the consequent changes in global temperature, it is essential to study its effects on animal...  相似文献   

6.
A 95‐day feeding trial was conducted to quantify the methionine + cystine requirement for finishing lambari, Astyanax altiparanae (6.10 ± 0.11 g). Six extruded isoproteic (310.14 g/kg crude protein) and isoenergetic (19.76 MJ/kg gross energy) diets were prepared to contain 6.71, 8.31, 11.31, 13.12, 15.59 and 19.74 g/kg dry diet of methionine + cystine. Quadruplicate groups of female lambari were randomly assigned to 24 aquaria (70 L each) and fed to apparent satiety six times daily. The methionine + cystine requirement was determined by quadratic regression analysis of growth performance, whole body composition, muscle development, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activity against dietary methionine + cystine concentrations, at 5% significance. Fish fed 6.71–11.31 g/kg dry diet of methionine + cystine showed increased weight gain, per cent weight gain, specific growth rate and protein efficiency ratio. There were no significant differences in whole body composition, muscle growth and activity of AST and ALT in fish fed the dietary treatments. In conclusion, according to the second‐order polynomial analysis of weight gain, the optimum dietary methionine + cystine requirements for finishing lambari were estimated to be 13.66 g/kg dry diet (4.40% dietary protein).  相似文献   

7.
ABSTRACT

In the present study, the effect of fish gelatin coating (FG; 4%, w/v) containing oregano (Origanum vulgare L.) essential oil (OEO; 1.2% w/v) on shelf-life extension of rainbow trout (Oncorhynchus mykiss) fillet stored under refrigerated storage (4 ± 1ºC) was investigated. The control and the treated fish samples were analyzed periodically for chemical (pH; total volatile basic nitrogen, TVB-N; peroxide value, PV; thiobarbituric acid, TBA) and microbiological (total viable count, TVC; psychrotrophic count) characteristics. The FG + OEO treatment produced significantly lower (p < 0.05) TVB-N values as compared to control and FG-coated samples after Day 6 and until the end of the storage period. The TBA values remained low and were found to fluctuate during storage. Results showed that TVC exceeded 6 log CFU g?1 on Day 8 of storage for control and FG-coated samples and Day 12 for samples coated with FG + OEO. The reduction of 1.05 and 0.83 log CFU g?1 of psychrotrophic counts was achieved by FG + OEO coating in trout fillet (p < 0.05) as compared with control and FG-coated samples, respectively. Therefore, the incorporation of OEO into FG coating may be a promising method of maintaining the storage quality of the rainbow trout fillet stored at refrigerated temperature.  相似文献   

8.
The aim of this study was to evaluate the anaesthetic effect of MS‐222 and propofol and determine their optimal concentrations for safe handling of the tetra Astyanax altiparanae in the laboratory. The fish were separated by length into three classes: I (1.5–5.0 cm), II (5.1–8.0 cm) and III (greater than 8.1 cm). Pilot tests were performed to evaluate the appropriate anaesthetic concentrations for inducing the five possible anaesthetic stages: I – sedation; II – light anaesthesia; III – deep anaesthesia; IV – surgical anaesthesia; and V – spinal collapse. After defining the maximum and minimum concentrations required to induce stage IV anaesthesia, the animals were exposed to five intermediate concentrations (n = 10 fish/concentration) of each anaesthetic for 15 min. The animals were then transferred to clean water to evaluate the time required for recovery. In addition, blood glucose levels were measured for class II and class III fish subjected to the previously defined ideal concentrations for each of the tested anaesthetics (n = 10 fish/treatment). Both evaluated substances are suitable to anaesthetize A. altiparanae. The optimal MS‐222 concentration was 90 mg L?1, and this result was similar for all three size classes. The optimal propofol concentrations for inducing surgical anaesthesia in the size classes I, II and III were 0.22, 0.23 and 0.27 respectively.  相似文献   

9.
The aim of this study was to evaluate Lactobacillus acidophilus, Streptococcus thermophilus, Bifidobacterium bifidum, and yeast Saccharomyces cerevisiae singly and in combination as probiotic supplements in Nile tilapia (Oreochromis niloticus) fingerling diets. All the probiotic-supplemented diets resulted in growth higher than the control. Best growth rate, food consumption, and food conversion (P < 0.05) were in the group fed a cocktail of the three bacteria. Feed cost, return on weight gain, and profit margin increased in fish groups fed diets inoculated with probiotics. Supplementation with Lactobacillus acidophilus, Bifidobacterium bifiduim, and the three-bacteria cocktail were most effective in eliminating mortality in an A. hydrophila challenge.  相似文献   

10.
研究丁酸钠植物精油复合制剂对南美白对虾(Litopenaeus vannamei)生长性能、肠道微生物及非特异性免疫的影响.试验分为2组,对照组饲喂基础日粮,试验组饲喂基础日粮+2.5 kg/t 丁酸钠植物精油复合制剂.结果显示,相比对照组,试验组南美白对虾增长率提高11.73%(P<0.01),质量增加率提高13.5...  相似文献   

11.
Abstract.— This paper describes current techniques used at our laboratory for the controlled spawning, maturation and larval rearing of the yellowtail snapper. Juvenile yellowtail snapper were obtained from Florida and transferred to the Fisheries and Mariculture Laboratory in July 1990. Temperature and photoperiod manipulation resulted in precocial spawning in 1991, with sustained successive spawning beginning in February 1992. Average weekly spawning from 1992–1994 was 308,000 and 247,000 eggs/tank, with fertilization rates of 46.1 % and 32.5% for fish maintained in two separate spawning tanks. Observations on spawning activity from 1995 to 1996, during which a decreasing trend in egg and larval quality was observed, imply a possible problem with broodstock nutrition. Evaluation of feeding regimes during this period indicated a shift to a high (almost exclusively) usage of fresh squid and a reduction in fish and shrimp. Returning to a feeding regime of alternating feedings of fresh fish, squid. and shrimp have yielded improved spawning and egg quality. Larval rearing techniques using live and prepared feeds has resulted in an overall survival of 3% from egg to advanced juvenile. Growout of first generation (F1) juveniles yielded a marketable size (1 1b) fish in 25 mo. Spawning of F1 fish hegan in 1998. larval rearing and grow out of F2 fish are currently underway. Results demonstrate that yellowtail snapper culture is technically feasible; however. further research to develop species specific culture techniques will be required before the culture potential of this species can be accurately evaluated.  相似文献   

12.
Beneficial utilization of yuzu (Citrus junos) peel was investigated to improve the commercial value of cultured yellowtail fish. The antioxidant effects of grated yuzu peel from pomace (yuzu paste) on prevention of dark muscle discoloration during storage in sliced yellowtail fish were tested. Four diets were prepared, containing 0, 10, 50, and 100 g yuzu paste in a 1,450-g diet (wet basis). Fish were fed one of the four diets for 10 weeks. Growth performance was not significantly different among the dietary groups, but fish fed a diet containing 100-g yuzu paste showed the least average body weight and a significant increase in fecal amount and fat levels in the feces, which suggest low digestibility and low absorption. Dark muscle discoloration was significantly reduced in all yuzu dietary groups compared to the control group during storage at 4°C. The optimal supplementation of yuzu paste in the fish diet is very effective at maintaining fish flesh freshness as a finishing diet without causing additional phosphorus or nitrogen pollution of the sea and inhibiting fish growth. This study provides a new way to utilize waste yuzu peel, which also helps reduce waste from yuzu processing.  相似文献   

13.
本研究分别以壳聚糖浓度、乳化剂用量和三聚磷酸钠用量为指标进行单因素试验,以粒径、PDI和Zeta电位为指标进行分析,制备壳聚糖?柑橘精油微胶囊。以挥发性盐基氮(TVB-N)值、SDS-PAGE电泳、硫代巴比妥酸值(TBA)和菌落总数(TVC)为指标分析壳聚糖?柑橘精油微胶囊在 凡纳滨对虾(Litopenaeus vannamei) 4℃贮藏过程中对其品质的影响。结果显示,与对照组相比,壳聚糖?柑橘精油微胶囊处理组可以明显抑制TVB-N值、TBA值和TVC值增长(P<0.05);SDS-PAGE图谱也显示实验组的肌球蛋白重链分解更慢。说明在4℃冷藏条件下,壳聚糖?柑橘精油微胶囊能够有效地抑制蛋白质的变性、脂肪的酸败和微生物的增长,从而延缓凡纳滨对虾腐败变质,延长凡纳滨对虾货架期3~4 d。  相似文献   

14.
A 66‐d feeding experiment was conducted to investigate the utilization of vegetable oils in Japanese seabass (initial weight: 10.09 ± 0.70 g). In experimental diets, linseed oil (LO) or soybean oil (SO) was used to replace 1/3, 2/3, and 3/3 of fish oil (FO) (Diets F2L1, F1L2, and LO, respectively, or Diets F2S1, F1S2, and SO, respectively). A diet with FO alone was used as the control diet. LO or SO supplementation did not reduce the specific growth rate (3.06–3.29%/d) and feed efficiency ratio (0.75–0.83) of fish, but group F2L1 showed significantly better growth (P < 0.05) and feed utilization (P < 0.01) than group SO. Total replacement of FO with LO or SO significantly reduced certain non‐specific innate immune responses. Total replacement of FO by LO significantly increased the lipid content of fish. Concentrations of long‐chain polyunsaturated fatty acids (LC‐PUFAs) in whole fish and tissues were significantly reduced by LO or SO supplementation. In conclusion, LO or SO supplementations did not reduce the growth of Japanese seabass but reduced the immune responses and LC‐PUFA concentrations. LO was a better lipid source than SO for Japanese seabass in terms of fish growth and immune responses.  相似文献   

15.
The present study was designed to determine the optimal dietary lysine requirement for jundiá, Rhamdia quelen, fingerlings. Groups of 17 fish (1.4 ± 0.1 g) were stocked in 120‐L tanks and were fed semipurified diets (33% crude protein [CP] and 3500 kcal metabolizable energy) containing increasing concentrations of lysine (3.0, 4.0, 4.5, 5.0, 5.5, 6.0, and 6.5% CP). After 119 d, fish weight gain (WG), specific growth rate (SGR), feed intake and feed conversion (FC), apparent net protein utilization (ANPU), body composition (CP, fat, and ash), and vertebral collagen were determined. WG and SGR increased as dietary lysine concentration in protein increased up to 4.5%, reducing at 6.0 and 6.5% lysine. Fish that were fed the lowest lysine concentration presented the worst feed conversion (FC), which improved for fish fed with 4.5% or more lysine. Feed consumption followed the same trend as FC. The highest ANPU was observed in fish fed with 4.5% lysine. Fish fed diets containing 4.5, 5.0, and 5.5% lysine accumulated more body protein (P < 0.05). Collagen vertebral concentration was significantly higher in fish fed with the 4.5% lysine diet. Dietary requirement for lysine was 4.5 or 5.1% depending on the statistical model used for estimation: broken line or polynomial regression, respectively. The requirements for the other essential amino acids were estimated on the basis of the ideal protein concept and were similar to the requirements for other fish species, except for isoleucine, leucine, treonine, and valine, which were higher for jundiá.  相似文献   

16.
A 56‐d feeding trial was conducted to evaluate the growth performance, feed utilization, biochemical composition, and antioxidant status of chu's croaker, Nibea coibor (12.6 ± 0.1 g) in net pens fed diets supplemented with various levels of crude palm oil: 0% fish oil (FO), 20% palm oil (2PO), 40% (4PO), 60% (6PO), 80% (8PO), and 100% (10PO). Weight gain and specific growth rate (SGR) were significantly lower in fish fed 8PO and 10PO diets. The increase of PO levels did not affect fish survival, feed intake, and feed conversion ratio. Feeding diet 10PO led to significantly higher lipid content in the liver, but not the whole body and dorsal muscle, than diets FO and 2PO. PO supplementation led to increased α‐tocopherol, but decreased thiobarbituric acid‐reactive substances, n‐3 highly unsaturated fatty acid (n‐3 HUFA), and n‐3/n‐6 fatty acid ratio, in both the liver and muscle. Hepatic superoxide dismutase and catalase were significantly higher in fish fed 10PO diet than FO diet. Polynomial regression analysis showed that the maximum SGR was obtained at 24.2% crude PO. Results of this study suggested that PO could replace up to 60% of FO without adverse effect on growth performance or nutritional quality of fish.  相似文献   

17.
ABSTRACT

The present study was conducted toestimate the optimum dietary supplementation level of Chlorella powder as a feed additive to optimize growth of juvenile olive flounder, Paralichthys olivaceus. Four experimental diets supplemented with Chlorella powder (CHP) at 0, 1, 2 and 4% (CHP0, CHP1, CHP2, and CHP4, respectively) of diet as a dry-matter (DM) basis were prepared. Three replicate groups of fish averaging 1.1±0.02 g were fed one of the four experimental diets for 12 weeks. After the feeding trial, fish fed the CHP2 diet had a higher (P < 0.05) weight gain (819%) than did fish fed CHP0 (707%) and CHP1(712%); however, there was no significant difference between fish fed CHP2 (8197%) and CHP4 (7559%) as among fish fed CHP0, CHP1, and CHP4 (P > 0.05). Fish fed CHP2 had a higher (P < 0.05) feed efficiency (134%) than did fish fed CHP0 (123%); however, there was no significant difference (P > 0.05) among fish fed CHP0 (123%), CHP1 (125%), and CHP4 (125%) as among fish fed CHP1 (125%), CHP2 (134%), and CHP4 (125%). Fish fed CHP2 and CHP4 had a lower (P < 0.05) serum glucose level (average 32.9 mg/dL) than did fish fed CHP0 and CHP1 (average 34.8 mg/dL). Fish fed CHP1 and CHP2 had a lower (P < 0.05) serum glutamic oxaloacetic transaminase (GOT) level than did fish fed CHP0 and CHP4. Glutamic pyruvic transaminase (GPT) levels significantly (P < 0.05) deceased as dietary CHP increased. Fish fed CHP2 and CHP4 had a less (P < 0.05) whole-body fat than did fish fed CHP0. These results indicate that the optimum dietary supplementation level of Chlorella powder as a feed additive in juvenile olive flounder could be approximately 2% of diet.  相似文献   

18.
The effect of dietary lipid on culture performance, fatty acid composition of carcass, and the liver polar lipid of surubim fingerlings Pseudoplatystoma coruscans was investigated. Five isonitrogenous (46.5% crude protein) and isolipidic (19% crude lipid) diets were formulated with squid liver oil (SLO) and white fat (pig lard-PL) as lipid sources. Diet 1 was supplemented with 12% SLO, diet 2 with 8% SLO and 4% PL, diet 3 with 6% SLO and 6% PL, diet 4 with 4% SLO and 8% PL, and diet 5 with 12% PL. Fish were fed to apparent satiation over a 64-d feeding trial. No statistically significant difference ( P >0.05) was observed in growth performance of fish. In contrast, fatty acid profile of fish carcass and liver polar lipid fraction was affected ( P 0.05) by dietary fatty acid composition. Palmitic (16:O) and the oleic (18:1n-9) acids were the major saturated and monoene fatty acids respectively found in fish carcass, independent of the lipid source in the diets. The total amount of saturated and monoene fatty acids was significantly higher ( P 0.05) in the carcass of the fish fed diets 4 and 5, than in the other fish. The concentration ( P 0.05) of eicosapentaenoic and docosahexaenoic acids and the n-3/n-6 ratio in fish carcass and in polar lipid fraction of liver increased in direct proportion to the level of squid liver oil in diet. Results of this experiment clearly demonstrated that both squid liver oil and pig lard have a positive nutritive value for surubim and that it is possible to increase the n-3 to n-6 ratio in favor of n-3, without loss in the growth performance, feeding fish with a diet containing a lipid source rich in this fatty acid.  相似文献   

19.
分别以豆油、菜油、混合油(豆油:菜油=1:1)作为脂肪源,制成3种试验饲料,饲养体重为(27.64±2.29)g的鲫57 d,对试验鱼生长、生物学性状、体成分、血清生化指标进行测定,以综合评价豆油和菜油对鲫(Carassius auratus)的影响并进行比较.结果表明,菜油组和豆油组终末体重差异不显著,但均显著高于混合油组(P<0.05);饲料系数、增重率、绝对生长率各组间均无显著差异;内脏指数菜油组和豆油组差异不显著,但均高于混合油组(P<0.05);菜油组的含肉率显著低于混合油组(P<0.05),两者与豆油组差异不显著;菜油组的肝体比显著高于混合油组(P<0.05),两者与豆油组差异不显著;菜油组的肠体比和豆油组差异不显著,但均高于混合油组(P<0.05);肠长比各组间差异均不显著;菜油组的肥满度最高,混合油组最低,且组间差异显著(P<0.05);豆油组肌肉粗蛋白含量显著高于菜油组(P<0.05),与混合油组间差异不显著;混合油组肌肉粗灰分含量显著高于菜油组(P<0.05),与豆油组含差异显著;鱼体肌肉水分、粗脂肪、肝胰脏脂肪含量及血清生化指标各组间差异不显著.研究结果显示,豆油、菜油单独作为脂肪源对鲫生长、血清牛化性状的影响没有显著差异,但豆油能够改善鲫的体形,提高鲫的肌肉粗蛋白含量,而2种油脂混合使用则抑制鲫的生长,其原因可能与鲫的消化道发育受到抑制有关.建议生产中使用豆油为鲫的脂肪源,并避免同时使用豆油和菜油.  相似文献   

20.
The present study aimed to assess the efficacy of supplemental plant essential oils (PEOs) on the growth performance and digestive processes of juvenile gilthead seabream. Three experimental diets were tested: (1) a control (CTRL) diet formulated with low marine‐derived protein level (19%); (2) CTRL diet supplemented with a blend of anise, citrus, and oregano essential oils at 1.2 g/kg (diet Phyto C); and (3) CTRL diet supplemented with a similar blend at 0.2 g/kg, but in encapsulated form (diet Phyto E). Triplicate groups of 20 fish (mean initial body weight = 27.9 ± 2.1 g) were fed the experimental diets over 63 d. Results showed that specific growth rate, voluntary feed intake, feed conversion ratio, and protein efficiency ratio were not significantly affected by the two dietary supplements. The commercial blend of PEOs tested here can be successfully incorporated into a low‐fishmeal diet to maximize protein and fat retention and to minimize nitrogenous losses in seabream juveniles. Phyto E presented a decrease in nitrogenous metabolic and fecal losses. The practical implications of including this plant‐based blend in aquafeeds can potentially include faster fish growth and improved production time, but these remain to be tested in a longer experimental trial.  相似文献   

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