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The size grading during fish farming benefits growth management and feed control, improving aquaculture efficiency. A guided live fish grading device was designed to solve the problem of high labor intensity and low efficiency in domestic live fish grading. The structural composition and working principle of the grading device were introduced, and the mechanical analysis and parameter design of the fish conveying mechanism were carried out. Based on the relationship between fish body mass and body shape parameters, the morphological data of experimental crucian carp were measured. Meanwhile, the power function fitting method was used to obtain the equation of the relationship between crucian body thickness and body weight, which serves as the basis for setting the distance between grading channels. When grading, the spacing between the guide plates on both sides of the grading channel is adjusted, and the grading channel is set to meet the fish specification requirements so that fish's body through the grading channel. Live fish grading performance experiment was carried out, with fish weight range of 0. 14-0. 33 kg and thickness range of 30-39 mm. Grading tests and effect analysis were conducted under three conditions of fish conveying speeds of 0. 15 m/ s, 0. 20 m/ s, and 0. 25 m/ s. The experimental results show that the grading accuracy can reach over 90% under normal conditions, and the appropriate grading speed and grading channel setting have higher efficiency. This guided grading device can quickly and accurately grade live fish, improving the efficiency of mechanized operations in the breeding process. [ABSTRACT FROM AUTHOR]

Copyright of Diamond & Abrasives Engineering is the property of Zhengzhou Research Institute for Abrasives & Grinding 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.)

Zacco tiaoxiensis, a new species of cyprinid fish from Tiaoxi river system in Zhejiang Province, southern China, is described. With morphological comparison, the new species is similar to Z. acanthogenys, which is widely distributed in Zhejiang Province. However, the new species could be distinguished from Z. acanthogenys by the following combination of characters: lateral- line scales comprising 41-44 (vs. 44-47), scales above lateral-line 8 (vs. 8-10), scales below lateral-line 3-4 (vs. 4-5), scales surrounding caudal peduncle 12-15 (vs. 14-17), for mature male individuals, the ventral fin reaching (vs. exceeding) the anus, etc. The morphological differences among the new species and the allopatric congener species of Z. sinensis and Z. platypus are mainly in the number of scales under the lateral line, comparable characters such as the ratio of head length to body length, and the color of the upper edge of the eyes when living. Moreover, the genetic analysis based on mitochondrial cytochrome b gene also supports that Zacco tiaoxiensis sp. nov. is a valid species. [ABSTRACT FROM AUTHOR]

The experiment was to investigate the effect of fly maggot meal replacement of fish meal on growth performance, body composition and serum biochemical indices of German mirror carp. A total of 540 German mirror carp with healthy body and neat size were randomly divided into six groups, with three replicates in each group and 30 fish in each replicate. The control group was basic diet, and the experimental groups were fed fly maggot meal to replace 20%, 40%, 60%, 80% and 100% fish meal in basic diet, respectively. The experiment lasted for 102 d. The results showed that the weight gain rate and protein efficiency of 40% group, 60% group, 80% group and 100% group were significantly lower than those of control group (P<0.05). The water content of the whole fish and fish muscle in 20% group, 40% group, 60% group, 80% group and 100% group was significantly higher than that in control group (P<0.05), the crude ash content of the whole fish in 20% group was significantly higher than that in control group (P<0.05), and the crude ash content of the whole fish in 100% group was significantly lower than that in control group, the crude ash content of fish muscle in 80% group was significantly higher than that in control group (P<0.05). The total crude protein of fish in 20% group, 40% group, 80% group and 100% group was significantly lower than that in control group (P<0.05), and the muscle crude protein of fish in 40% group and 100% group was significantly lower than that in control group (P<0.05). The serum CAT activity of fish in 20% group was significantly higher than that in control group (P<0.05), the serum SOD activity of fish in 20% group, 60% group and 80% group was significantly higher than that in control group (P<0.05), the serum MDA content of fish in 40% group, 60% group and 80% group was significantly lower than that in control group (P<0.05), the serumALT activity of fish in 60% group was significantly higher than that in control group (P<0.05), and the serum AST activity of fish in 80% group and 100% group was significantly lower than that in control group (P<0.05), the AST activity of fish serum in other experimental groups was higher than that in control group. The experiment indicates that the replacement of 20% fish meal protein by fly maggot meal can improve the activity of antioxidant enzymes in liver of German mirror carp, without affecting change the growth performance and composition of fish body. [ABSTRACT FROM AUTHOR]

【Objective】A new record species of the genus Xanthoectroma from China—Xanthoectroma aquilinum Mercet 1925 is described detailly, and the DNA bar code information of this species is also provided, which is a reference for the study of biology, ecology and molecular biology of this new record species, and also to enrich the data of the Encyrtidae.【Method】 The net-sweeped specimens were sorted, the morphological characteristics were observed and measured under a digital stereo microscope; Genomic DNA was extracted using non-damage extraction method, and the mitochondria Cytochrome Oxidase I（COI） gene of X.aquilinum was amplified with universal primers. 【Result】The main identification characteristics of female specimens were whole body yellow and with obvious sulcus; The tip of the wing was slightly more than 1/2 of the abdomen, the postmarginal vein was the same length as the marginal vein, and the abdomen was significantly longer than the sum of the head and thorax. The main identification characteristics of male specimens were that the body length was significantly shorter than that of females, the top of the head was brown, the back of the thorax was dark brown, and the end of the abdomen has obvious triangular black-brown spots. The identification characteristic figures of the new record species, as well as the COI genetic sequence, were provided, the phylogenetic tree showed that it was more closely related to Anagyrus and Aenasius.【Conclusion】The new record species is X.aquilinum Mercet 1925,upload the COI gene sequence to NCBI. [ABSTRACT FROM AUTHOR]

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.)