Search

Monopterus albus is one of the popular aquatic fish in Asia. Manual processing of eel cannot fully meet the large- scale production at present, due to the time-consuming, laborious, and low safety. In view of its slender and slimy body, an eel- cutting machine is required for the consumption of Monopterus albus. In this study, a miniature machine of automatic cutting was designed for the living Monopterus albus with a sticky surface. The machine consisted of conveying, clamping, and cutting parts. The double-clamped wheel to roller was used to capture the eel for transportation during cutting. The switch between laparotomy and back dissection was realized to change the feeding channel. The adaptive mechanism was equipped to meet the requirements of different sizes of eel cutting. Firstly, the geometry and weight parameters of Monopterus albus were measured using a straight ruler and precision electronic balance. The tribological parameters on the surface of Monopterus albus were measured by the inclined plane. The mechanical parameters of Monopterus albus meat were verified by compression test. Secondly, according to the rigid-flexible coupling principle, the rigid-damping model was equivalent to the contact between the Monopterus albus body and the clamping wheel and slide. The rigid-flexible coupling model was established by Abaqus and Adams simulation software. The analysis model was optimized to take the conveying time of the fish body, output speed, clamping force, and whole machine vibration as the test indexes in single-factor tests, such as the spring stiffness, slope Angle of the slide, and the speed of the clamping wheel. The results show that the clamping force first increased and then decreased with the increase of spring stiffness and the vibration amplitude of the whole machine decreased. But there was little influence on conveying time and output speed. The output time of the fish body decreased with the increase of slope angle, while the output speed, clamping force, and vibration of the whole machine increased. There was an increase in the conveying time of the fish body, the output speed, the clamping force, and the vibration of the whole machine, with the increase of the speed of the clamping wheel. The single- and multi-factor analyses were carried out to obtain the optimal working conditions. Specifically, the clamping wheel speed was 600 r/min, the spring stiffness was 1 200 N/m, and the slope angle was 16°. Finally, the processing experiment was performed on the automatic cutting machine for eel. There was consistency in the vibration amplitude range and the relationship between the three directions of the machine measuring points with the theoretical analysis. At the same time, the output speed of the fish body output machine was also measured to better agree with the theoretical analysis. The cutting of the machine under optimal working conditions has fully met the requirements. The correctness of the theoretical analysis was also verified by the test. The rigid-flexible coupling model can provide a strong reference to research and develop the subsequent equipment. [ABSTRACT FROM AUTHOR]

The scale of Monopterus albus farming in Hubei Province is large, but there are few pre-treatment processing devices. The current Monopterus albus pretreatment device is mainly dissected and killed. Aiming at the problems of poor stability, low efficiency, and low meat yield of existing Monopterus albus deboning devices, an adaptive Monopterus albus deboning device was designed, which was mainly composed of laparotomy components, transitional components, and deboning components. The theoretical analysis of the process of fish laparotomy, transition transportation, and deboning was carried out, and the key factors affecting the performance of the deboning device were obtained. Taking the meat yield rate and sensory quality scores as evaluation indexes, the single-factor test of the distance between the pressure wheel and the V-block, the initial clearance of the transition wheel, the rotational speed of the transition wheel, the shape of the deboning blade disc and the rotational speed of deboning blade disc were carried out to determine the reasonable range of each parameter. The test results showed that when the distance between the pressure wheel and the V-block was 15.50-16.75 mm, the meat yield rate was higher; when the initial clearance of the transition wheel was 9 mm, the sensory quality scores of the fish body was the highest; the increase of the rotational speed of the transition wheel and the rotational speed of the deboning blade disc is beneficial to improve the meat yield rate and sensory quality scores; and the shape of the boning blade disc had little influence on the meat yield rate and the sensory quality scores. The orthogonal test of four factors and three levels was carried out with the distance between the pressure wheel and the V-block, the initial clearance of the transition wheel, the rotational speed of the transition wheel, and the rotational speed of the deboning blade disc as the test factors. The results showed that the order of significance of each test factor on the meat yield rate was the distance between the pressure wheel and the V-block, the initial clearance of the transition wheel, the rotational speed of the transition wheel, and the rotational speed of the deboning blade disc; and the order of significance on the sensory quality scores was the initial clearance of the transition wheel, the distance between the pressure wheel and the V-block, the rotational speed of the transition wheel and the rotational speed of the deboning blade disc. When the distance between the pressure wheel and the V-block was 16.75 mm, the initial clearance of the transition wheel was 9 mm, the rotational speed of the transition wheel was 648 r/min, and the rotational speed of the deboning blade disc was3200 r/min, the deboning effect was the best. The meat yield rate of the deboning device was 84%, and the total sensory quality scores of the fish after processing reached 17.3. The device can process Monopterus albus with a body mass of 75-150 g, and the production efficiency reaches 16.8 strips/min. Compared with the current commercially available deboning device, the feeding is more convenient and the production efficiency is higher. It can provide a reference for the research of Monopterus albus pretreatment device. [ABSTRACT FROM AUTHOR]

The aim of this experiment was to study the effects of stickwater hydrolysate meal on growth, intestinal digestive enzymes, serum biochemistry and immune indexes of rice field eel (Monopterus albus). Healthy rice field eel with an initial weight of (25.00±0.20) g were used as the study subjects, and three treatment groups were set up with three replicates in each group and 50 rice field eel per box. Stickwater hydrolysate meal was used to replace 0, 2.5% and 5% fishmeal in the basal diet (fishmeal content of 40%), recorded as FM, SHM2.5 and SHM5.0, respectively, and the breeding experiment lasted 56 days. The results showed that the replacement of some fish meal (SHM2.5 and SHM5.0) by stickwater hydrolysate meal did not have any significant difference on the weight gain rate (WGR) of rice field eel (P>0.05); but significantly increased the intestinal trypsin (TPS) activity (P<0.05); the replacement of some fish meal by stickwater hydrolysate meal had no significant effect on the serum total cholesterol (TC), urea nitrogen (BUN), total bile acids (TBA), glutamic-pyruvic transaminase (GPT), glutamic oxaloacetic transaminase (GOT), complement 3 (C3), malondialdehyde (MDA), alkaline phosphatase (AKP) and superoxide dismutase (SOD) of rice field eel. There were no significant differences in the levels of alkaline phosphatase, malondialdehyde and superoxide dismutase (P>0.05); the replacement of some fish meal by stickwater hydrolysate meal significantly increased the levels of serum immunoglobulin M (IGM), complement 4 (C4) and lysozyme (LZM) (P<0.05), and the levels of serum glucose (GLU), triglyceride (TG) and alkaline phosphatase in the SHM5.0 group were significantly elevated (P<0.05). The results indicated that proper replacement of fish meal by stickwater hydrolysate meal has no adverse effect on growth, feed utilization and intestinal digestive enzymes of rice field eel and will enhance the immune function of rice field eel. [ABSTRACT FROM AUTHOR]

Swamp eel (Monopterus albus) is an important freshwater culture fish in China and has the characteristic of hermaphroditism and natural sexual reversal. Currently, there is a lack of artificial varieties within swamp eel cultivation, and the fry of mainly rely on the wild catching. Gynogenesis, a method for rapidly obtaining fish population with stable heredity and excellent character, was explored in this study. Meiogynogenesis induction was established in swamp eel, resulting in the creation of three gynogenic populations characterized by deep-yellow coloration. Flow cytometry analysis showed that the cellular DNA contents of gynogenic eels were consistent with those of wild type fish, and chromosome counting confirmed the diploid nature with 48 chromosomes. Histological analysis demonstrated the development of ovaries in the gonads of gynogenic eels, indicating normal diploid functionality. Microsatellite diversity analysis showed that the effective number of alleles (Ne), Shannon's information index (I), polymorphism information content (PIC), observed heterozygosity (Ho) and expected heterozygosity (He) in gynogenic eels were significantly lower than those in the wild population. The genetic homozygosity in gynogenetic eels exhibited a significant improvement. The genetic distance increased and the genetic similarity decreased between gynogenetic groups. In summary, the gynogenetic population of the deep-yellow swamp eels provides new materials for breeding excellent varieties. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Hydrobiology is the property of Editorial Department of Journal of Hydrobiology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to solve the problems of the low feeding rate, incomplete digestion of Monopterus albus, and nitrogen pollution of water, the study aimed to isolate high-yield protease producing strains from artificially cultivated Monopterus albus, which will provide strain resources for the production of microbial proteases and the development of probiotics in the future. High-yield protease producing strains were preliminarily isolated from the artificially cultivated Monopterus albus by the combination of the transparent circle method of skimmed milk powder culture medium for primary screening and the Folin-phenol method for secondary screening to measure protease activity. The safety of the strains was tested through a hemolysis test and a drug sensitivity test, and the strains were identified by adopting a combination method of the physiological and biochemical characteristics of the strain. The fermentation conditions for protease production were optimized through single factor and orthogonal experiments. A high-yield protease producing strain named Ma-4 was screened, and it was identified as Bacillus aryabhattai, which can also produce the hydrogen peroxide enzyme. Its optimal enzyme production conditions were the fermentation time of 48 h, the fermentation temperature of 36, the optimal amount of soluble starch of 15 g/L, the optimal amount of beef powder of 15 g/L, and the pH value of 6.0. After optimization, the enzyme activity increased to 288.14 U/mL, representing a 3.34-fold improvement. The study indicates that the strain Ma-4 is a high protease-producing, catalase-producing, non-hemolytic and drug-resistant Bacillus aryabhattai, which can provide strain resources for the development of micro-ecological preparations of Monopterus albus. [ABSTRACT FROM AUTHOR]

Copyright of South China Fisheries Science is the property of South China Fisheries Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The experiment was conducted to investigate the effect of Se-Met supplementation on growth performance, selenium content in muscle tissue and serum biochemical indexes of Monopterus albus. Three hundred Monopterus albus with body weight of (27.55±0.85) g were randomly divided into five groups, with three replicates in each group and 20 Monopterus albus in each replicate. The Monopterus albus in control group were fed with basal diet, and Monopterus albus in SM1 group, SM2 group, SM3 group and SM4 group were fed with basal diet supplemented with 0.3, 0.6, 0.9 and 1.5 mg/kg Se-Met, respectively. The experiment lasted for 21 d. The results showed that compared with control group, the weight gain rate of Monopterus albus in SM2 group was significantly increased (P<0.05), and the feed coefficient was decreased (P<0.05). The content of selenium in muscle tissue of Monopterus albus in SM2 group, SM3 group and SM4 group was significantly higher than that in control group (P<0.05). The serum total cholesterol content of Monopterus albus in Se-Met groups was significantly higher than that in control group (P<0.05), the content of total cholesterol and high density lipoprotein cholesterol in SM2 group were the highest, and the content of low density lipoprotein cholesterol in SM4 group was significantly higher than that in other groups (P<0.05). The activity of serum alkaline phosphatase, glutamyltransferase, aspartate aminotransferase and alanine aminotransferase in Se-Met groups were higher than those in control group, and the activity of SM4 group was the highest. Serum IgM content of Monopterus albus in Se-Met supplemental groups was higher than that in control group. The experiment indicates that adding proper amount of Se-Met in diet can improve the growth performance, immune function and selenium content in muscle tissue of Monopterus albus, and the optimal supplemental level is 0.6 mg/kg. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Hydrobiology is the property of Editorial Department of Journal of Hydrobiology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Hydrobiology is the property of Editorial Department of Journal of Hydrobiology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Swamp eel (Monopterus albus) is one of the most important cultured fresh water species with high economic value in China, however, the present compound diets could not meet the growth and gonad development of swamp eel broodstocks, which hampered the large-scaled aquaculture of this species, therefore, the reproduction improvement of swamp eels by optimization of the compound diet formulation is on the urgent need. Antarctic krill meal is rich in sustainable resources and has the same nutritional level as fish meal, which meets the requirements of a new type of animal protein source for feed. Reports showed that Antarctic krill meal inclusion improved the growth and reproduction of several aquatic animals. In this study, two-winter-age female Monopterus albus with an initial body weight of (36.41±3.62) g was adopted. Antarctic krill meal was included to replace 0, 20%, 40%, 60%, 80%, and 100% fish meal to make 6 groups of iso-nitrogenous and iso-energetic diets. After 12 weeks of culture, the growth performance, body composition, hepatic anti-oxidant capacity and non-specific immunity, and fecundity of six groups of experimental eels were determined. The results showed that the weight gain rate (WGR) and specific growth rate (SGR) of eels had no significant differences in 20% replacement group and the control group (P>0.05). However, the further increase of Antarctic krill meal substitution (>40%) led to the growth performance reduction. In muscle, crude protein concentration was higher in 20% substitution group than the other experimental groups; no significant differences were observed in the crude lipid and ash concentrations among different groups in muscle of swamp eels (P>0.05). In ovary, the nutrient composition had no significant difference between groups of 20% substitution group and the control group (P>0.05). Concentrations of crude protein and crude lipid decreased significantly while the moisture concentration increased gradually by Antarctic krill meal substitution from 60% to 100%. The further detection of the anti-oxidant capacity of liver revealed that superoxide dismutase (SOD) activity decreased gradually albeit with the increase of malondialde-hyde (MDA) concentration in groups of Antarctic krill meal substitution higher than 40%. The catalase (CAT) activity in 100% substitution group was lower than the other five groups. The following non-specific immunity evaluation of liver suggested that no significant differences were observed between 20% substitution group and the control group in parameters of alkaline phosphatase (AKP), complement 4 (C4), and immunoglobulin M (IgM) (P>0.05). When the Antarctic krill meal substitution level were 60% or higher, the AKP activity showed the increased trend, while concentrations of C4 and IgM decreased instead. Lastly, fecundity of swamp eels in all groups were examined. The 20% Antarctic krill meal substitution did not influence fecundity parameters including gonadosomatic index (GSI), absolute fecundity, relative fecundity and serum estradiol concentration (P>0.05) in swamp eels. GSI in 80% and 100% groups were lower than that of 40% and 60% groups. From 60% to 100% substitution groups, the absolute fecundity, relative fecundity and estradiol concentrations decreased gradually with the increase of Antarctic krill meal inclusion. Egg diameters increased gradually with the increase of krill meal inclusions, but significant differences were only found from 100% group to groups of 0 and 20% (P<0.05). From the above results, it showed that the growth performance, ovarian nutrient composition, hepatic anti-oxidant capacity and non-specific immunity, and fecundity will not be influenced when 20% fish meal were replaced by Antarctic krill meal in diets of female swamp eels. Higher substitutions of Antarctic krill meal will intensify the adverse effect on this fish species. Therefore, the substitution of Antarctic krill meal of fish meal should not exceed 20% in formulated diets of female Monopterus albus. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Hydrobiology is the property of Editorial Department of Journal of Hydrobiology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The study was to investigate the effect of corn gluten meal partial replacement of fish meal on growth performance and serum indexes of Monopterus albus. 108 young Monopterus albus weighing 13 g were selected and randomly divided into three groups with three replicates in each group, and 12 Monopterus albus in each replicate. The experimental treatment groups were equal in energy and nitrogen, control group (CON group) diet contained 68% fish meal, and the experimental group replaced 10% fish meal (R1 group) and 20% fish meal (R2 group) with corn gluten meal on basis of control group feed. The experiment lasted for 56 d. The results showed that compared with CON group, the weight gain rate, specific growth rate, crude protein apparent digestibility and crude protein content in muscle of Monopterus albus in R1 group and R2 group were reduced significantly (P<0.05), feed coefficient was significantly increased (P<0.05). Serum triglyceride levels and total protein in R1 group and R2 group were significantly lower than those in CON group (P<0.05). The catalase of liver of Monopterus albus was increased significantly in R1 group and R2 group (P<0.05). The experiment indicates that replacing part of fish meal with corn gluten meal can improve serum indexes of monopterus albus and has the potential to replace part of fish meal. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of South China Fisheries Science is the property of South China Fisheries Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Environmental Science & Technology (10036504) is the property of Editorial Board of Environmental Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Henan Agricultural Sciences is the property of Editorial Board of Journal of Henan Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of South China Fisheries Science is the property of South China Fisheries Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Southern Agriculture is the property of Journal of Southern Agriculture and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)