Four ursane type triterpenes have been isolated from the methanolic extract of the aerial parts of Agrimonia pilosa Ledeb. (Rosaceae) through repeated silica gel and reverse-phase C-18 column chromatography. Their chemical structures were elucidated as ursolic acid (1), pomolic acid (2), tormentic acid (3), and corosolic acid (4) on the basis of their MS, , and spectral data. Compounds 2 and 4 were isolated from the genes of Agrimonia for the first time.
For establishing a basal diet for the Pacific bluefin tuna Thunnus orientalis (PBT), feeding stimulants were initially identified by omission test using the synthetic extract of horse mackerel, Trachurus japonicus. Four feeding trials were conducted using juvenile PBT weighing (trial 1, 2 and 3) and (trial 4), which were originated from an artificial seedling production. The fish fed the casein diet with each test solution were added at the ratio of 100 g casein diet to 100 g jack mackerel muscle. A complete synthetic extract of jack mackerel containing all 3 fractions, amino acid, nucleotide and organic nitrogenous base, exhibited a comparable feeding stimulant activity compared to that of natural extract. The omission of nucleotide or amino acid fraction showed lower feeding activity, but the omission of other nitrogenous fraction maintained a similar feeding stimulant activity compared to that of the synthetic extract (trial 1). Inosine-5' monophosphate (IMP) was identified as a major constituent for maintaining feeding activity. The mixture of L-alanine, L-glutamic acid, L-histidine, L-lysine, taurine and IMP induced a similar feeding activity compared to that of the synthetic extract (trial 2 and 3). In trial 4, the highest feeding activity was finally obtained in the mixture of L-histidine, L-glutamine and IMP, followed by the synthetic extract, the mixture of L-lysine, L-alanine and IMP, IMP and the mixture of L-histidine, L-glutamic acid, L-lysine and L-alanine. These results revealed that the mixture of L-histidine, L-glutamic acid and IMP for the proper feeding stimulant of PBT in this study.
Conducting aquaculture while achieving the two objectives of maintaining a natural ecosystem and sustainable aquaculture can only be achieved when a production system with minimal ecological impact on the natural environment is used. aquaponics to achieve this goal can reduce the amount of water used in the aquaculture process and improve the recycling rate of abandoned materials and nutrients. This enables the combined production of a variety of fish and vegetables compatible with environmental sustainability. In this study, we aimed to examine the applicability of Aquaponics to contribute to the sustainability and environmental protection of the Korean aquaculture industry.BR The development direction of aquaponics shows two trends that focus on improving RAS technology and recycling nutrients that produce a mixture of fish and agricultural products. Both trends contributed to environmental sustainability. The potential for future breakthroughs in waste production and removal in feed production can further improve the sustainability of fish and agricultural production in aquaponics. In this study, we have studied the changes in the growth of each species, the number of fish, the number of fishes, and the number of breeding, and it has been shown that various wastes(nutrients) derived from fish are a major component explaining the ecological effects of aquaponics. Based on these results, there was no significant difference in the growth of carp in the aquaponics cultivated in Korea, but the growth of lettuce absorbed the nutrients generated in carp cultivation and increased by more than 15% Respectively. Therefore, we expect to be able to utilize aquaponics industrially using various varieties in Korea.
Artificially-produced juvenile black sea bream Acanthopagrus schlegeli (total length , body weight ) were released in eelgrass, Zostera marina bed and their initial food organism and changes of body compositions were investigated for one month after release. Predation rates in fish sampled on 1st and 3rd days were 79%, increased up to 100% on 7th and 10th days, and then decreased on 30th days as 75%. Major prey organisms was composed of mainly Amphipoda and Gastropoda. Ratio of Amphipoda and Gastropoda in stomach were highest in fish sampled on 15th and 1st days after release, respectively. Crustacea and Algae were maintained about 20% during a sampling period. Visceral weight index (VWI) offish sampled 20th and 30th after release were significantly higher than that of initial. Carcass crude protein and lipid contents of released fish were showed significantly decreasing; however carcass n-3 HUFA composition was showed increasing tendency with the passage of time after release. Eelgrass bed was supposed to be helpful for the released fish to adjust their feeding habits and biochemical metabolism to the natural environment within a short period after release.
Red sea bream Pagrus major (RSB) weighing 0.09 g were fed on test diets, composed of 65% fish meal supplemented with 0.49% Crataegi fructus (Cf) and a mixture of Massa medicata, Cf, Artemisia capillaries and Cnidium officinale (HM) or a control diet without herbs, in trial 1. After air exposure and anaesthesia treatment, higher stress tolerances were obtained in herbal groups than control group. Moreover, after challenge test with Vibrio anguillarum, mortalities of the herbal groups were lower than the control group. There was no significant difference in growth performance among the treatments. Feed efficiency (FE) of the test groups was 124–141%. In trial 2, RSB weighing 0.11 g were fed on diets composed of 35% fish meal and 30% enzyme treated fish meal (EFM) with the same herbal treatments as trial 1. The herbal groups revealed higher final body weight and specific growth rate (SGR) and lower daily feed intake than those of the control group. The FE of test groups was 172–203%. These results indicate that the dietary herbs supplementation acts not only as recovery enhancer for some rearing stresses but also as growth enhancer, which is accelerated with dietary EFM in the early juvenile stage of red sea bream.
This study aimed to investigate the productivity of red seabream (Pagrus major) raised in brass net cages and fiber net cages installed in the offshore sea with a depth of more than 35 meters. The weight gain (WG), daily growth rate (SGR), feed coefficient ratio (FCR), and survival rate (SR) of red seabream were calculated to compare the productivity of a brass net cage and a fiber net cage. The productivity of red seabream was calculated by giving weight gain (WG), feed efficienct ratio, and survival rate of 50%, 30%, and 20% weights, respectively. The growth rate, feed efficienct ratio, and survival rate of red seabream were higher in the brass net cage than in the fiber net cage, and the productivity was improved by 34.7% (P<0.05).
We investigated the growth and survival in seedling production, and growth performance was compared with the different rearing tanks and protein source of formulated feed for juvenile Pacific bluefin tuna Thunnus orientalis (PBT). The survival rate at the end of nursery culture at 30 days after hatching was , and total length and mean body weight were and , respectively. Growth performance has no significant difference in fish reared by different tanks forms for 10 days. In order to develop an artificial diet, we evaluated the dietary utility of enzyme treated fish meal (Bio-CP, BIO) for juvenile PBT. Only diet BIO sustained similar growth and higher feed efficiency, and final carcass lipid content as compared to those of Sand lance (SL) These results revealed that BIO-CP a suitable dietary protein source, could sustain growth of PBT.
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